(Sanitized)

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP79T01049A002600030004-6
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 195
• Document Creation Date: December 12, 2016
• Document Release Date: March 6, 2000
• Sequence Number: 4
• Content Type: REPORT

Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
MICROWAVE COMMUNICATION EQUIPMENT
Repeater Service Unit MI-31495-A
? TECHNICAL DATA
? DESCRIPTION
? MAINTENANCE
? REPLACEMENT PARTS
RADIO CORPORATION OF AMERICA
ENGINEERING PRODUCTS DIVISION, CAMDEN, N. J.
PRINTED IN U.S. A.
SIO4
18-33231
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
TECHNICAL DATA
Power Inputt
Tube Complement
a, Filament Heaters: 14 watts at 115 v, 50/60 cycles,ac
Symbol
Type
Punction
b. Plate Supply:50. milliamps at 250'v dc
6W'
12AX7-
Calling Amplifier:
Levels:
6V2'
12ATT
Calling Gate' and Fault Lock.?
out Gate
a. Transmitting Amp. Input: Voice
6V3'
12AX7
Fault Amplifier
Output: 4 volts rms (approx.) across 60,000 ohms.
b. Receiving Amp. Input: 5 volts rms (approx.)
6V4
12AT7
Handset Amplifier and Mike
Amplifier
across 10,000 ohms
6V5
6AH6?
Fault/Ring Oteillator
Output: Handset
Weight and Dimensions:
Ringing Frequency
285 cycles
Fault Signal Frequency:
2800 cycles
Weight: 16 lbs:
Height: 83A'.'
Depth back of panel: 41/2e
Depth- front of panel: 4"
Width: Standard 19" Rack
Mounting
DESCRIPTION
The Repeater Service Unit MI-31495-A is designed
for mounting in either a standard 19" 'open rack or
cabinet and is usually used at drop or thru re-
peater stations,. This unit serves to create fault
tone signals that are transmitted to the other
stations, when the receiver or transmitter is in-
operative or other faults develop. These signals
when received at a terminal station identify the
repeater station sending the signal and the type of
fault. The unit also contains facilities for voice
communication with any or all of the stations of
a microwave system. These signals travel on the
same microwave carrier that contains the multiplex
channels.
Repeater Service Unit MI-31495-A consists of
both a receiving branch and a transmitting branch
operating in conjunction with sensing relays and a
fault code circuit.
One function of the transmitting branch is to
generate and send out pulsed tone signals whenever
either repeater transmitter and/or receiver becomes
inoperative or when any one of three other station
faults develop.
The occurrence of any one of these Units will en-
ergize a relay to start a fault signal transmission cy-
cle. It is possible for more than one station fault to
be sent during each fault transmission cycle. There
are six fault relays, 6K1, the E-W transmitter relay;
6K10 for the 'W-E transmitter; 6K3, for either
receiver/modulator; and three external fault relays
6K4, 61(5, and 6K11. Each of these relays has a con,
tact B which initiates operation of motors 6M1 and
681 through contact 6K8C and 6M1A. Motor 6M1
closes contact 6M1B to keep itself operating and
opens 6M1A in order to stop 6B1 after it completes
one revolution. 6B1 turns the commutator brush
arm through one revolutioh in about 12 seconds,
while maintaining its circuit via commutator seg-
ment Y. Relay 6K6 is energized when the brush arm
contacts a commutator segment connected to its coil.
The segments concerned with station identification
are connected directly to 6K6, while those concerned
with fault identification are connected to, 6K6
through the C contacts of their respective fault re-
lays, 6K1, 6K3, 6K4, 6K5, 61(10 and 61(11. Thus
in the event of a receiver fault, for example, 6K6
will be operated as the brush arm contacts segment
A, since the associated fault relay, 6K3, is operated
and its C contact closed. When closed, the contact
of relay 6K6 applies the 2800 cycle tone generated
by oscillator 6V5 to the transmitted service chan-
nel. One set of pulses is transmitted and a 'second
set of pulses cannot be transmitted until 6M1 has
completed its cycle about four minutes later, closing
6M1A. The transmitted service channel is fed
through filter 6FL2 to the baseband unit and from
there to the modulator in the receiver/modulator.
The service channel is transmitted On the micro-
wave carrier to all other stations of the system. The
2800 cycle tone pulses on the system operate a com-
mutator brush arm in the terminal station service
unit which is in synchronism with the commutator
brush arm of the repeater station. The action of the
Approved For Release 2001/03/04 :091A-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
a,RS-2
terminal commutator brushes lights a combination
of lamps on an indicator panel which identifies the
exact repeater station sending the fault tone and the
nature of its trouble.
In a system of 10 repeater stations or less each sta-
tion has its own two digit fault codf number. Code
number combinations are available for use when
wiring the segments of commutator 6E1 of the serv-
ice upits for their code designations. The 10 two
digit code- combinations are: 1-2, 1-3, 1-4, 1-5, 2-3,
2-4, 2-5, 3-4, 3-5, 4-5.
In systems of more than 10 stations between ter-
minals the following code combinations can be used
to supplement the above: 1-2-3, 1-2-4, 1-2-5, 1-3-4,
1-3-5, 1-4-5, 2-3-4, 2-3-5, 2-4-5, 3-4-5. The segments
corresponding to the code numbers and segment Z
are wired together as shown in the example in the
schematic of figure RS-4.
One of the commutator segments 3, 4 or 5 that is
not used for station identification is used to operate
relay 6K7 which resets 6K1 or 6K10 which would
otherwise "lock up" on a transmitter failure due to
the self-locking action of the fault relay employed
in the transmitter. Commutator segments A, B, C,
D and 6 are used to indicate the particular type of
6JI 6FLI 6V3 6VI
trouble occurring at the station. Segment A is used
to indicate receiver failure; B, transmitter failure,
and C, D, and 6 may be used for other indications
desired by the user. Contacts A of relays 6K1, 6K3
and 6K10 serve no purpose in the equipment de-
scribed in this book. At standby stations, contact C
of 6K1 and 6K10 initiate switchover operation when
either relay is operated.
The transmitting portion of the circuit consists
of a phase shift type audio oscillator 6V5 which
normally oscillates at a frequency of 2800 cycles and
is keyed on and off by relay 6K6 to transmit the
fault tone pulses. Oscillator 6V5 can also be shifted
to a frequency of 285 cycles by the operation of
calling pushbutton 6S1. Transmission of this 285
cycle tone activates buzzers in all other service units
of the system, and is used as a ringing signal to
attract the attention of the other operators. The
output of the service telephone plugged into jack
6J2 is amplified by the 6V4B audio stage and is
passed together with the ring or fault tone through
filter 6FL2 to the communication channel of the
relay system. The voltage level to filter 6FL2 from
fault oscillator 6V5 is set by OSC OUTPUT con-
trol 61144 and from service telephone amplifier
6V4B by MIKE OUTPUT control 6R48.
6V2 61(9 6L1 61(8
611 672
6JII
6R6
6J8
76365
6J3 6FL2 STK NO. 6V4 STK NO. 6J2 6R44 6SI
57533 30075
STK NO. 6R49 6V5 6K 10 6KI 6S2
54521
Figure RS-1?Repeater Service Unit, A41-31495-A?Front View
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
GAIN
RECEIVER- E.W ? ONTROL
410
MODULATOR)SERV. CH.
OUTPUT W? g GO
NTL
SERV. CHA N.
HANDSET
RECVR.- MOD.
OR 6.6. AMP
SERV. CHAN.
INPUT
N.141700.0
4-
3 KC
LOW PASS
Krim
AMPLIFIER 14--- GAIN
CONTROL
AMPLIFIER
TAP GAIN
CONTROL
TAP GAIN
CONTROL
RING)
285
CYCLE
SELACTOR
--?
(FA U LT I
2800
CYCLE
SELECTOR
SIGNAL
RELAY
LOC K
OUT
RELAY
SIGN AL
BUZ Z ER
HOLD
OUT
CIRCUIT
FROM
FAULT
SENSING
RELAYS
RELAY ? E-W TRANS.
3 KG
LOW PASS
F ILTER
265/2800
CYCLE
OSCILLATOR
FAULT
CODER
RELAY W E TRANS.
GAIN
?
ONTROL
-W RECVR.
RELAY 4
W-E RECVR.
(E
SIGNAL
PUSH
BUTTON
TEST
PUSH
BUT TON
L AY EXTERNAL
RELAY EXTERNA(.
won,
RELAY
EXTERNAL
Figure RS-2?Repeater Service Unit?Block Diagram
In the receiving section the fault/ring tone and
voice frequencies (300 cycles to 3000 cycles) are
received from both the E-W and W-E receivers and
passed through a 3000 cycle low pass filter 6FL1 to
prevent any multiplex frequencies above 3000 cycles
from entering the service unit circuits. W-E INPUT
gain control 6R5 and E-W INPUT gain control 6R6
control the voltage level to filter 617E1 from the W-E
and E-W receivers respectively. One circuit fed by
this filter is amplifier 6V1, selective to the 285 cycle
ring tone, and gate tube 6V2A which controls relay
6K9. This circuit operates a buzzer when a ring
tone (285 cycles) is present in the service signal.
A second branch of the receiving section consists
of the fault amplifier 6V3, responsive to the 2800
cycle fault tone, gate tube 6V2B and relay 6K8. Re-
ception of a 2800 cycle signal causes relay 6K8 to
operate, opening contact 6K8C which prevents the
starting of motors 6M1 and 6B1 and consequent
fault tone transmission from the station. Since as
many as 15 repeater stations may be cascaded in a
section of a system it is possible that two or more
may attempt to transmit fault signals at the same
time. This 'would result in the appearance of in-
correct information at the terminal station. Relay
61(8 therefore prevents a repeater station from start-
ing a fault transmission when any other repeater
station is sending a fault tone. In addition relay
contact 6K8A by connecting capacitors 6C9A and
6C9B to the 6V2 grid, delays the release of 6K8 for
a sufficiently long time to permit the repeater sta-
tion first sending the fault tone to complete its fault
transmission before another station starts its own
fault transmission.
The final element of the receiving branch is a
cathode follower stage which amplifies the voice
frequencies to jack 6J2 for the telephone handset
receiver. The handset signal level is set by HAND-
SET VOLUME control 6R11.
Bridge audio jack 6J12 and bridge fault jack 6J13
are provided to accommodate the addition of MI-
31072 Service Channel Bridging at junction stations.
MI-31072 permits the use of only one repeater
service unit to serve both stations of the junction.
Jacks 6J12 and 6J13 provide the means of supplying
the fault/ring tones, voice signals and fault code
information to the bridging unit and of receiving
local fault information from the bridging unit.
CONTROLS
a. The E-W INPUT and W-E INPUT controls
(6R6 and 6R5) vary the amplitude of the service
channel input to filter, 6FL1, from the E-W and W-E
receivers.
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Cl/RS-4
b. The HANDSET VOLUME control (6R11)
varies the amount of voice signal voltage applied
to the grid of handset amplifier 6V4A.
c. The HANDSET jack (6J2) is for connecting
the service channel telephone handset.
d, The OSC OUTPUT (6R44) screwdriver
control adjusts the level of the ring fault tone
oscillator output fed to low pass filter 611.2.
e. The MIKE OUTPUT screwdriver control
(6R49) adjusts the gain of microphone amplifier
6V4B.
f. The CALLING pushbutton (6S1) when
pressed changes oscillator 6V5 from a fault tone
(2800 cycle) generator to a ring tone (285 cycle)
generator and connects this fault/ring tone signal to
the low pass output filter 6112.
g. The TEST pushbutton (6S2) when pressed
causes motors 6M1 and 6B1 to run so that the op-
eration of the fault code circuits may he checked
h. The Variable Tap Resistor, 6R53, reached
from the rear of the unit, controls the amount of
dc voltage for energizing relays 6K1 and 6K10.
i. The Fault Oscillator Control 6R37 is a screw
driver adjusting variable resistor, reached from the
rear of the unit, for setting the frequency of
oscillator 6V5 to the fault tone frequency of 2800
cycles.
j. The Ring Oscillator Frequency Control 6R-11
is a screw driver adjusting variable resistor, reached
from the rear of the unit, for setting the frequency
of oscillator 6V5 to the tone frequency of 285
cycles. The adjustment is made with the CALLING
button pushed.
k. The INPUT pinjack (6J1) is for connecting
test leads to a Ballantine Model 300 voltmeter to
measure the audio signal voltage output of filter
6FI.1.
I. The OUTPUT pinjack (6J11 )is for connect-
ing test leads to a Ballantine Model 300 voltmeter
to measure the audio signal voltage output of the
fault ring tone oscillator 6V5 and microphone
amplifier 6V-iB.
STK. NO.
95342
TB2
0-1 6 R9 1-0
0-46R54).-0
046655 1-0
STK. NO.
STK. NO
95343 61(6 61(8 6C 2 1 61(9 6C98 6C8 6XV3 6R23 6R31
95344 6K5 6K7 6C 19 6XV2 6C5 6XV 1 6XV4 6)1
6.111 615
6.14
6J6
TBI
0411FM-0
046622 1-0
0466211-0
0466331-0
0466201-0
0466271-0
0466291-0
6C7 1-0
04.EL1-0
0-1 6C4
? WEI ?
? CIMI ?
olsc
0-16C 5 1-0 /1k:// / /
???
111??
It+
6JI3 6KI I /
6.1,12 6M1
0-16R13 1?o
o--1 car a) I?o
046656 f-o
0-16657 1-0
0-16614 I-0
0-16 1717 1-0
0+71-1-0
043 RI 6 1-0
6CI 1-0
046C12 1-0
? ELM ?
0-11C 13 1-0
0411:1}43
6S2
18586
&Ka /61 ,/ 61(10 6x V5
61(3 61(1 6R53
6R4 6R44 6J2 6R I I
6R49 6S1 6R37 6R30 6L2
6.18
6.13
? ran ?
0406351-0
\ 046 R501-0
0-fircn-c,
6.17
Figure R5 3?Repeater Service Unit, MI 31495 A----Rear View, Dust Cover Removed
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03104: CIA-RDP79T01049A002600030004-6
MAINTENANCE
'General Notes
Fault Relay and Commutator
a. At each routine repeater station inspection,
check the operation of the timer motor 6M1 and
6B1 and the commutator brush arm. The timer
should take four minutes and the commutator
brush arm should take 12 seconds to complete one
revolution. When the commutator brushes pass
segment ''Z" on the cominutator, 6K6 should be
? .operated.
b. -Whien faulty commutator contact becomes
. evident increase the commutator brush pressure as
? follows:
Loosen the screw holding the brush arm and
rotate the arm in the direction that will increase the
pressure of the brushes against the commutator
.13.1ate and then tighten the arm in this position.
Be certain that the pressure of the brushes against
the segments is sufficient to make positive contact.
c. A check of the proper operation of the com-
mutator assembly 6E1 in conjunction with the
terminal fault indicating equipment may be made
by simulating each of the five types of faults at
: the repeater and observing the lamp panel at the
terminal station for the proper identifying code.
The faults can be simulated by pressing the armature
of each of relays 6K1, 6K3, 6K4, 6K5 and 6K11
in turn. Use the maintenance telephone channel
for checking the results of the test at the terminal
station.
d. Adjust variable resistor 6R53 for a voltage
at 6K1 of 113 v with both transmitter output meter
relays (1M2) in the condition of having their red
and black arms touching (contacts closed).
Input Circuit
a. The?normal adjustment of the W-E and E-W
INPUT controls, 6R5 and 6R6, is the maximum
clockwise position.
b. Excess gain is available in both the calling
amplifier and fault amplifiers. If the input voltage
to these circuits is too great the connections to the
6R9, 6R54 and 6R55 or the 6R10, 6R56, 6R57
resistance networks may be reduced to a lower tap.
The input voltage to the calling amplifier will
need to be reduced if the voice signals in the
maintenance channel causes the call buzzer to
sound.
c. Adjust the HANDSET VOLUME control to
the desired listening level.
Output Circuit
The adjustment of the level of the fault and
service signals applied to the baseband or receiver/
modulator units from the repeater service unit is
described as follows:
TYPICAL REPEATER SERVICE UNIT VOLTAGES
The following are typical voltages between various tube pins and ground as read with a vacuum tube volt-
lneter. All voltages are tic unless otherwise noted.
Tube
Type
Function
Pin
#1
Pin
#2
Pin
#3
Pin
#4
Pin
#5
Pin
#6
Pin
#7
Pin
?#8 .
Pin
#9
6V1
12AX7
Calling Amp.
250
0
2.5
0
0
140
1.0
2.5
6.3
ac
6V2
12AT7
Calling Gate
Fault Lockout
250
0
8.4
0
0
250
1.0
8.4
6.3
ac
6V3
12AX7
Fault Amp. .
250
0
2.0
0
6.3
ac
6V4
12AT7
Handset - Mike
Amp.
250
0
3.0
0
0
90
0
1
6.3
ac
6V5
6AkH6
Osc.
0
1.9
6.3
0
150
150
1.9
?
ac
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Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
RS-6
Drop Repeater Station
a. The OSC OUTPUT and MIKE OUTPUT
adjustments are made as follows:
1. Connect an audio voltmeter (Ballantine
Model 300 or equivalent) to pin 6J8-2 and ground.
2. Press the CALLING button and adjust the
OSC OUTPUT Control for a meter reading of
1.32 volts.
3 Speak into the handset microphone and
adjust the MIKE OUTPUT control for a meter
reading of from 0.5 to 0.8 volt on voice peaks.
b. The audio output connections must be made
at the junction of 6R51 and 6FL2. The specified
levels cannot be obtained if the wrong output con-
nection is used.
Thru Repeater Station
a. The OSC OUTPUT and MIKE OUTPUT
adjustments are made as follows:
1. Connect the audio voltmeter (Ballantine
Model 300 or equivalent) to pin 6J8-2 and ground.
2. Press the CALLING button and adjust the
OSC OUTPUT control for a meter reading of
0.057 volt.
3. Speak into the handset microphone and
adjust the MIKE OUTPUT conteol for a meter
rearling of from 0.023 to 0.035 volt on voice peaks.
b. The audio output connection must be made
at the junction of 6R59 and 6R51. Severe overload-
ing of the modulator will result if the wrong out-
put connection is used.
REPLACEMENT PARTS LIST
REPEATER SERVICE UNIT?MI-31495-A
Symbol No.
Description
Drawing No.
Stock No.
6131
Motor, synchronous, clock type, 115 v., 60 cycle
8833318-1
95340
6C1 to 6C4
Capacitor, fixed, mica, 560 mmf -?-2%, 500 v. '
722022-553
72841
6C5
Capacitor, fixed, paper, 0.1 mf -.?10%, 400 v.
735715-175
73551
6C6
Capacitor, fixed, paper, 0.47 mf -?-20%, 200 v.
735715-33
73787
6C7
Capacitor, fixed, mica, 9100 mmf -?2%, 300 v.
722029-562
95383
6C8
Capacitor, fixed, paper, 0.01 mf -?10%, 400 v.
735715-163
73561
6C9A, 13
Capacitot, fixed, paper, 4.0 mf +20 ?10%, 100 v.
8887709-153
95341
6C10
Capacitor, fixed, paper, 0.1 mf -1-.10%, 400 v. Same as 6C5
735715-175
73551
6C11
Capacitor, dry electrolytic, 10 mf, 25 v.
442901-46
52533
6C12 to 6C14
Capacitor, fixed, mica, 1000 mmf -?-2%, 500 v.
722022-559
90003
6C15
Capacitor. fixed, paper, 0.1 trif ?-10%, 400 v. Same as 6C5
735715-175
73551
6C16
Capacitor, dry electrolytic, 10 mf, 25 v. Same as 6C11
442901-46
52533
6C17
Capacitor, fixed, paper, 0.01 mf ?-10%, 400 v. Same as 6C8
735715-163
73561
6C18
Capacitor, fixed, paper, 0.1 mf -?10%, 400 v. Same as 6C5
735715-175
73551
6C19
Capacitor, fixed, paper, 0.47 mf ?-20%, 200 v. Same as 6C6
735715-33
73787
6C20
Not used.
6C21
Capacitor, fixed, mica, 2200 mmf -.1-10%, 500 v.
727866-155
39660
6C22
Capacitor, fixed, ceramic, 1500 mmf +100 ?0%, 500 v.
449696-3
73748
6E1
Commutator Assembly?(following parts only available)
744080-502
Clip, contact brush holding clip
128727-1
95344
Contact, sliding, for code signal commutator assembly
128746-1
95343
Plate, repeater code signal commutator plate assembly, complete with
contacts and terminals
4 5 8943- 502
95342
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Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Symbol No,
Description
Drawing No.
Stock No.
6FLI
Filter, low pass, 3.6 to 100 Ws impedance 5000 ohm input and output
8833307-2
95345
6FL2
Filter, low pass, 3.6 to 100 kc/s impedance 10,000 ohm input and output
8833306-2
95346
611
Buzzer, door bell type, 8-12 v., 60 cycle
8848315-1
95347
631
Connector, female, pin jack
742565-1
93678
632
Connector, female, telephone jack
8845648-1
94232
633
Connector, male, 6 contact, chassis mtg.
181494-3
28507
634 to 637
Connector, female, 6 contact, chassis mtg.
181494-4
18534
638
Connector, male, 6 contact, chassis mtg. Same as 633
181494-3
28507 .
639
Connector, female, 6 contact, chassis tug. Same as 634
181494-4
18534
6310
Connector, male, 6 contact, chassis mtg. Same as 633
181494-3
28507
6311
Connector, female, pin jack. Same as 631
742565-1
93678
6312
Connector, male, 6 contact, chassis mtg. Same as 633
181494-3
28507
6313
Connector, female, 6 contact, chassis mtg. Same as 634
181494-4
, 18534
6K1
Relay, dc, coil, 68 v., 3 form "A" make, contacts
174913-8
95348
6K2
Not used.
61(3
Relay, ac, midget type, coil, 115 v., 50/60 cycle, 3 p.s.t. normally open
458952-2
95349
contacts
?
6K4 to 61{.7
Relay, ac, midget type, coil, 115 v., 50/60 cycle, d.p.d.t. contacts ...
458952-1
95350
6K8
Relay, dc, coil, 72 v., 2 form "C" break-make contacts
174913-7
95351
61(9
Relay, dc, coil, 41 v., 1 form "C" break-make contact
174913-6
95352
6K10
Relay, dc, coil, 68 v., 3 form "A" make contacts
174913-8
95348
6K11
Relay, ac, midget type, coil, 115 v., 50/60 cycle, d.p.d.t. contacts. Same
as 6K4
458952-1
95350
6L1
Reactor, iron core, 350 nth
88333091
95359
6L2
Reactor, air core, r-f choke, 21 microhenry
8896181-1
57918
6M1
Motor, timer, clock type, 115 v., 60 cycle, with one s.p.d.t. microswitch
attached and fixed cam with 6? notch
458949-1
95360
6121, 6R2
Resistor, fixed, composition, 3900 ohm 7_4=10%, V2 w
82283-69
502239
6R3, 6R4
Resistor, fixed, composition, 4700 ohm th-10%, V2 w
82283-70
502247
6R5, 6126
Resistor, variable, composition, 5000 ohm ?10%, 2 w.
737829-30
94039
6R7, 6R8
Resistor, fixed, composition, 5600 ohm ?-10%, V2 w
82283-71
502256
6R9, 6R10
Resistor, fixed, composition, 4700 ohm -.?-10%, I/2 w. Same as 6R3
82283-70
502247
6R11
Resistor, variable, composition, 10,000 ohm -1710%, 2 w.
737801-43
68833
6R12
Resistor, fixed, composition, 1500 ohm ?10%, 11/2 w-
82283-64
502456
6R13
Resistor, fixed, composition, 1000 ohm -2:10%, V2 w
82283-62
502210
6R14
Resistor, fixed, composition, 1 meg -?5%, I/2 w.
82283-231
502510
6R15
Resistor, fixed, composition, 270,006 ohm ?-1096, V2 w.
82283-91
502427
6R16 to 6R19
Resistor, fixed, composition, 1 meg =1:5%, 1/2 w. Same as 6R14 ..
82283-231
502510
6R20, 6R21
Resistor, fixed, composition, 56,000 ohm -?-10%, V2 w.
99126-83
28741
Approved For Release 2001/03/04: CIA-R0P79101049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
0./Rs 8
Symbol No.
6R22
6R23
6R24
6R25
6R26
6R27
6R28, 6R29
6R30
6R31
6R32
6R33
6R34
6R35
6R36
6R37
6R38
6R39, 6R40
6R41
6R42, 6RA3
6R44
6R45
6R46
6R47
6R48
6R49
6R50
6R5I
6R52
6R53
6R54
6R55
6R56
6R57
6R58
6R59
6R60
6R61
6S1
Description Drawing No.
Resistor, fixed, composition, 1000 ohm -2:5%, 1 w. 90496-159 512210
Resistor, fixed, composition, 1500 ohm J:10%, 1/2 w. Same as 6R12 82283-64 502456
Resistor, fixed, composition, 33,000 ohm -...t10%, 1/2 w. 82283-80 502333
Resistor, fixed, composition, 390,000 ohm -?-10%, 1 w.. 90496-93 32725
Resistor, fixed, composition, 2.7 meg -?-10%, 1/2 w- 82283-103 72788
Resistor, fixed, composition, 1000 ohm 175%, 1 w. Same as 6R22 90496-159 512210
Resistor, fixed, composition, 56,000 ohm -J:10%, V2 w. Same as 6R20. 99126-83 28741
Resistor, fixed, composition, 4700 ohm ?-10%, 1/2 w. Same as 6R3 82283-70 502247
Resistor, fixed, composition, 270 ohm -?-10%, 1/2 w- 82283-55 30929
Not used.
Resistor, fixed, composition, 39,000 ohm -1.-10%, 1 w- 90496-81 71084
Resistor, fixed, composition, 180 ohm -?-1004, 1 w. 735730-53 502118
Resistor, fixed, composition, 12,000 ohm -1:10%, 2 w. 99126-185 522312
Resistor, fixed, composition, 8200 ohm -?-596, V2 w- 82283-181 502282
Resistor, variable, composition, 25,000_ohm -?-10%, 2 w. 737854-4 95367
Not used.
Resistor, fixed, composition, 22,000 ohm 1/2 w. 82283-191 502322
Resistor, variable, composition, 500,000 ohm -.1:10%, 2 w 737854-5 95368
Resistor, fixed, composition, 220,000 ohm -?-5%, 1/2 w. 82283-215 502422
Resistor, variable, composition, 200,000 ohm -?-10%, 2 w 737854-6 95369
Resistor, fixed, composition, 22,000 ohm J:10% 1/2 w. 727834-78 502322
Resistor, fixed, composition, 47,000 ohm -L-10% 1/2 w. 82283-82 502347
Resistor, fixed, composition, 220 ohm -?10%, 1/2 w. 82283-54 502122
Resistor, fixed, composition, 15,000 ohm -?-10%, 1/2 w. 82283-88 502415
Resistor, variable, composition, 500,000 ohm -?--100/0, 2 w. Same as 6R41 737854-5 95368
Resistor, fixed, composition, 39,000 ohm =.1:10%, 1 w. Same as 6R33 90496-81 71084
Resistor, fixed, composition, 12,000 ohm -..L-5%? V2 w. 82283-185 502312
Not used,
Resistor, adj. wire wound, 10,000 ohms -?10%, 25 w.
Stock No.
449695-6 202931
Resistor, fixed, composition, 4700 ohm -?-10%, 1/2 w. Same as 6R3 82283-70 502247
Resistor, fixed, composition, 5600 ohm 1/2 w. Same as 6R7 82283-71 502256
Resistor, fixed, composition, 4700 ohm -?10%, V2 w. Same as 6R3 82283-70 502247
Resistor, fixed, composition, 5600 ohm -?10%, 1/2 w. Same as 6R7 82283-71 502256
Resistor, fixed, composition, 130 ohm, :L10%, 1/2 w. 82283-52 502115
Resistor, fixed, composition, 470 ohm -?-10%, 1/2 w. 727834-58 30499
Resistor, fixed, composition, 1000 ohm 1/2 w. Same as 6R13 82283-62 502210
Resistor, fixed, composition, 1000 ohm ?10%, 1/2 vv. 735730-62 502210
Switch, push leaf type, non-locking, 3 break, 1 make contacts with
black bakelite button
458953-3, 95370
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
? a-RS-9
Symbol No.
Description
Drawing No.
Stock No.
6S2
Switch, push leaf type, non-locking, break-make contact, with black
bakelite button
4589534
95386
6S3
Switch, snap action, bakelite case, s.p.d.t. contacts
8810605-1
97447
6T1
Transformer, bell ringing .
458947-1
95371
6T2
Transformer, filament
949385-1
94196
6X1 to 6X4
Socket, tube, 9 pin miniature
984055-2
56333
6X5
Socket, tube, 7 pin miniature
99370-2
53539
Miscellaneous
Knob, round bakelite (for 6R11)
712336-507 .
30075
Screw, thumb, brass, back cover holding
8886111-2
94391
Shield, tube, 7 pin miniature type
99369-2
54521
Shield, tube, 9 pin miniature type
8858642-3
57533
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
\NE )NPUT
6;,R1 rGR5, GR3
3300 5000.\ 4700
-? ?
GRB
5630
-
C,R2 6Re-, GR4
3300 5000 4-100
EW INPUT
BRIDE AUDIO
6F LI
iN OuT
470C
f ?
4
6R54700
INPUT
?
CALLING AMPL.
2 A X7
?-?
6R
270K
VAULT
AMPL
I2AX7
- ?-?
5
GRIO
4700 "t)
6R56
4700
GR57
5600
13
CAL - tNG GATE
12 AT 7 -
GC5 6CG
aimF 0 47 MF
6K9 ?
GCI 002
6RGO, 6R16 560
?
1000 ? I MEG
t 4
6R18 ' 9
iMEG.,EtRI9 '
1MEG.
6RI3
V\A-
1000
FAULT LOOKOUT GATE
1::50M140
T607
3,0
GC13
?
0.47MFT
6**3
4JI 5
9
GR23-(
1500,
G.A./V 2-A
6R 20
?
56K
1 56K I
6R22
)000 ?
Ka
608
.01 MF
A
I 50 2
6R26`,
27
MEG
HANDSET AMPL.
I 2 AT 7
3
?-
1000
P- 4
6R2B
56K
) 6R29A
6C9t,
4MF
6R25
390K
6 R24
331(
6R53
I OK
SEE N0TE.?2
HANDSET
VOLUME
SEEAOTE SRI]
10K
6R
4700
OSC
6AH6
5
9
6Y/V4-A
61'2
- 'J1
HANDSET
6R3I 6J2
3.4
270 2
5"3
(6R33
39K
6R35
I2K
6X/v5
7
4 3
SR34
10-1VV\,-?
180
6CII
IOMF
6012
1000
6R6I 6R36
1000 82776R37
25K
SEE N0TE'63
\CAM
500K
6R39
22K
6R42
220K
6CI-4-16C151_ 1
1
1?1000 O. 1.1-
m p
6C I3
1000
A
r 1-
K
-
BRIDGE FAULT
6-.13
0,20
-0 4
6K"
...11S-1 I,
(
12
-,,.A1 \.,c? N....4
l
1 /
1 k?--
4 A
I
?
CALLING
6R40 i..t. ?
22K GSI I SEE R44
I ..-..
2.00n
VS' t
GR43 1 6C2I
i .
12200
220K
-._
OUT
UT
GCle
DAMP
GJII .6FL2
6R46 6
47K 1P4 OUT
r-
ORBS ERN
OSC
OUTPUT
6R45
22K
470
THRU
RPTR
I2K )DROP
RPTR.
MIKE
AMPL. GCI7
1(.0[MF
tira
391, 6R48 0
C 150K z-
616Y,'44
7
10 MF
M KE
OUTPUT
W-E E-V4 W-E
PEC/MOD REC/ TRANS
6J4 6,15
101 20r--' ?0)21 --67-q-i ?Ot 20-
]4U- 41 -0340 -0340
105 40 05 -II 05 60 05 60
E-W W-E
TRANS t/i.1 B PLUG
6,J7 mue, 6.J3
? 4,
E-W
BB PLJG
GJEt
2 111
6cr2 I
14 a1-
1510.,---
SI
16511
??
TERM
6J9 I I
GE4
' I
-I- 0 -,--- b
. B I , f
4
1 /
_ -
- ----'--- +--,. ; ---.?
1 I .1 1 .--0.----t-- -_-_,
1- 1 IT? 611.4
I I
4 Ci.j) 6K5
I 1
?
!
- - t- - t_ _ _ _
1
6K11
1
Z'
worl t (4_7
LE
INRI 04- --4----
1111. or)
? B
TEST
652
- o D--
C ;KG
c
4
L
r
6 s.7
OPEN
FOR FT2
(1--, ALL CAPACITOR VALUES GIVEN IN MMF AND ALL RESISTOR
VALUES GIVEN IN OHMS UNLESS OTHERWISE SPECIFIED
NOTES:
I-COMMUTATOR SHOWN CONNECTED FOR. REPEATER
STATION NO.i (CODE 12).
2-WHEN USED IN CONJUNCTION WITH MI-31072, SERVICE
CHANNEL BRIDGING UNIT, JUMPERS FROM PINI TO PIN2
AND PIN 570 PIN6 OF 6JI2 ARE REMOVED.
3-ARROWS BESIDE RESISTORS INDICATE CLOCKWISE
ROTATION OF POTENTIOMETERS.
SAME AS PART I EXCEPT OPEN CIRCUIT BETAEEN
MiN AND MAKE CIRCUIT BETwEEN 6J3 FIN 6
ALSO OPEN CIRCUIT BETWEEN OP AND MAKE
CONNECTION BETWEEN OE M.
D 629526-9
Figure RS-4?Repeater Service Unit, MI-31495- A?Sc hematic Diagram
?
L1-1,410-5
r-'64-611.6-
62-81[11- 4
142-4,52-2
?-61.643-9
17
202-6137 1
r- el - 6PC 1 -7
669
5 so
4 2 5.6,15-5
1269
r: 405-6J125
5
1-1639A11- 1
r-164-6.11- 1
1019
.7-84 WU
6944-3
51-1
6-6146,
2-672.5
44135.6
1264
37
IFL1
7-24
a; OUT k 3 k
71
1
RS-14
,---916 646- 4714
65
H
101t
"316-
, 90643-2 '
89445-4
0108
126.647- I 2 6J?
1075
41 -4511? 2
21-6(1-X
22-4.19
1-4
3-67112
,164-47 - 3,
65-6611 -5,
1
F21-662-1
2.22-676-4
4444,3
25472- I
5 6K4.
411-4,.J9-2
172-621-2
- 162,696-2
, 07 T"''
.-.44002 GrEt
I-4.63 2
1074
1073 CAI
404411694
3-61 Ll- I
229-66., 4
- 19-661 3
30-6113
2201-?19.1
6-4435',
.133-EL I-C
42 6
67463 -6
- -4
4-4.12-5
3-647-2
4 -644-5
47-6.J7-6
e3 4,J4- 4
126
1007 10041
5)-{-614291-4
46- 475-1
- ?44-4161-3I 61-65-6s a- 7
?47-4453-3
83-fiR11- 2
04.6-L2.-1
95-6)14)
68-6./7-2
k2I- 629-4
1 10
619
r91-6.113-4
i-169-425-7
'7-664 -1
-61135-
1-151-6147-7
1017
1262,
6:7
1000
1023 1009,
,4C,4
67 61131-4
05-41134
W6405-641-
4.17
1251
,016 (2
5.113
291
172-611 -6
IS, -641-7
54-6S2.2-,
65-4113. 5 -
127
- - - - - - -
6526, 6c. 1.--4
L-204-615.2 _ ? - - -
r-66-445
-105
4O404-6..112 5:1r .414) 0
...it!,14
40
7-
3.53 5 j
-^ 68-4,1
, 4-21,22.. 76&6
88 15 314 -502.
vx,RE. NO
,t.c.,_Isivr '
DE SCRIPT iON
PS NO OR '
02LAWING 410-01393
,7t1,1 110
wItee Nos
NOT USED
c
?Lop Ans, cONDUCTOR
I7 7/010
314
' -C 6v,i52,sEs,....
P5 724 1
6,
t,- 34 w ..
80
41-47
RED
63
131U
---
66
65
81-67
CAR
.....
,.._.__ 0'06
,
.226
t41-148
ILL-
RE15/153A. -
64
a
1320/6611
82
_
i_ iv-i-rz
18-92
%._44624'
83
_,,--
YEL/PILD
84
2011006
',LA.
35/9
4 - I.___AL
22r232
241
371:. 7/010
P5724
9)724-5
-1
V
224
661194.1214. 16/010
67
400-405
. tot!: ,Elb,.1 zo
.9017 CAS-2 StRELOAp.L ..e 6455,91
',NNE? C?(* 94,192 .0)2 IAA 85105
54
012,7,,E.---4. ----
t
716,12515, 353
60
,25. - 510 4...6 'MS 71)150.46 ,0
42 1,0 ..en,n
18
-192-4,13-3
-no.6K3? 7
,,, 934-696 3 iosi 6610 , ,,_ , .. e :
,-.231-6411- 5- -
21.0-620::::1-,
---,_
651
J2
679, -IC -
27- 631
6C ,6
Z__75 4
-1.6-n}-,025 ,
_
9 4
z1
P50
0
00
-
;
237
-I -
N07ES ,r, _ ARE ../..,16E 14.1.. 4113-E TE--7,947.5N.
Z50._117EX. A - E. E.17.2 74_ C5NNECT,INE :$ING TEN& 91, AL
70 BE IN ACCORLANCE 40 76 RCA STANDARD PRA.C.T.CE,
3(6211 66711 5510-10 _57164C0120 ITEN192
4 CONNECTION 310011417 37 A 007 06 835 v+182 IRO,: AT F 71467 THESE
CONNECTIONS ARE MADE 137 ONE PIECE OF WIRE
575
GC.
6_112-1 i
E
Figure RS-5?Repeoter Service Unit, MI-j1495-A?Connection Diagram
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
703
MICROWAVE COMMUNICATION EQUIPMENT
Repenter Service Unit MI-31495-C
? TECHNICAL DATA
? DESCRIPTION
? MAINTENANCE
? REPLACEMENT PARTS
RADIO CORPORATION OF AMERICA
COMMERCIAL ELECTRONIC PRODUCTS, CAMDEN, N. J.
PRINTED IN U. S. A.
DU 567
v
18-33231-3
Approved For Release 2001/03/04: gA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
)CRS-1
TECHNICAL DATA
Power Input:
Tube Complement
a. Filament Heaters: 14 watts at 115 v, 50/60 cycles ac
Symbol
Type
Function
b. Plate Supply:50 milliamps at 250 v dc
6VI
12AX7
Calling Amplifier
Levels:
6V2
12AT7
Calling Gate and Fault Lock-
out Gate
a. Transmitting Amp. Input: Voice
6V3
12AX7
Fault Amplifier
Output: 4 volts rms (approx.) across 60,000 ohms
b. Receiving Amp. Input: 5 volts rms (approx.)
6V4
12AT7
Handset Amplifier and Mike
Amplifier
across 10,000 ohms
6V5
6AH6
Fault/Ring Oscillator
Output: Handset
Weight and Dimensions:
Ringing Frequency:
285 cycles
Fault Signal Frequency:
2800 cycles
Weight: 16 lbs.
Height: 83/4"
Depth back of panel: 41/2"
Depth front of panel: 4"
Width: Standard 19" Rack Mounting
DESCRIPTION
The Repeater Service Unit is designed for
mounting in either a standard 19" open rack or
cabinet and is usually used at drop or thru re-
peater stations. This unit serves to create fault
tone signals that are transmitted to the other
stations, when the receiver or transmitter is in-
operative or other faults develop. These signals
when received at a terminal station identify the
repeater station sending the signal and the type of
fault. The unit also contains facilities for voice
communication with any or all of the stations of
a microwave system. These signals travel on the
same microwave carrier that contains the multiplex
channels.
Repeater Service Unit consists of both a receiv-
ing branch and a transmitting branch operating
in conjunction with sensing relays and a fault code
circuit.
One function of the transmitting branch is to
generate and send out pulsed tone signals whenever
either repeater transmitter and/or receiver becomes
inoperative or when any one of three other station
faults develop.,
The occurrence of any one of these faults will en-
ergize a relay to start a fault signal transmission cy-
cle. It is possible for more than one station fault to
be sent during each fault transmission cycle. There
are six fault relays, 6K1, the E-W transmitter relay;
6K10 for the W-E transmitter; 6K3, for either
receiver/modulator; and three external fault relays
6K4, 610, and 6K11. Each of these relays has a con-
giasiSP0Vg8' fls:14)WseTgIrteNitAitefV etk-
6B1 through contact 6K8C and 6M1A. Motor 6M1
closes contact 6M1B to keep itself operating and
opens 6M1A in order to stop 6B1 after it completes
one revolution. 6B1 turns the commutator brush
arm through one revolution in about 12 seconds,
while maintaining its circuit via commutator seg-
ment Y. Relay 6K6 is energized when the brush arm
contacts a commutator segment connected to its coil.
The segments concerned with station identification
are connected directly to 6K6, while those concerned
with fault identification are connected to 6K6
through the C contacts of their respective fault re-
lays, 6K1, 6K3, 6K4, 6K5, 6K10 and 6K11. Thus
in the event of a receiver fault, for example, 6K6
will be operated as the brush arm contacts segment
? A, since the associated fault relay, 6K3, is operated
and its C contact closed. When closed, the contact
of relay 6K6 applies the 2800 cycle tone generated
by oscillator 6V5 to the transmitted service chan-
nel. One set of pulses is transmitted and a second
set of pulses cannot be transmitted until 6M1 has
completed its cycle about four minutes later, closing
6M1A. The transmitted service channel is fed
through filter 6FL2 to the baseband unit and from
there to the modulator in the receiver/modulator
at a drop repeater station or directly from 6FL2 to
the modulator at a thru repeater station. The serv-
ice channel is transmitted on the microwave car-
rier to all other stations of the system. The 2800
cycle tone pulses on the system operate a commu-
tator brush arm in the terminal station service unit
which is in synchronism with the commutator
brush arm of the repeater station. The action of the
RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
.13 RS-2
terminal commutator brushes lights a combination
of lamps on an indicator panel which identifies the
exact repeater station sending the fault tone and the
nature of its trouble.
In a system of 10 repeater stations or less each sta-
tion has its own two digit fault code number. Code
number combinations are available for use when
wiring the segments of commutator 6E1 of the serv-
ice units for their code designations. The 10 two
digit code combinations are: 1-2, 1-3, 1-4, 1-5, 2-3,
2-4, 2-5, 3-4, 3-5, 4-5.
In systems of more than 10 stations between ter-
minals the following code combinations can be used
to supplement the above: 1-2-3, 1-2-4, 1-2-5, 1-3-4,
1-3-5, 1-4-5, 2-3-4, 2-3-5, 2-4-5, 3-4-5. The segments
corresponding to the code numbers and segment Z
are wired together as shown in the example in the
schematic of figure RS-4.
One of the commutator segments that is not
used for station identification is used to operate re-
lay 6K7 which resets 61(1 or 6K10 which would
otherwise "lock up" on a transmitter failure due to
the self-locking action of the fault relay employed
in the transmitter. Commutator segments A, B, C,
D and 6 are used to indicate the particular type of
trouble occurring at the station. Segment A is used
to indicate receiver failure; B, transmitter failure,
and C, D, and 6 may be used for other indications
desired by the user. Contacts A of relays 6K1, 6K3
and 6K10 serve no purpose in the equipment de-
scribed in this book. At standby stations, contact C
of 6K1 and 6K10 initiate switchover operation when
either relay is operated.
The transmitting portion of the circuit consists
of a phase shift type audio oscillator 6V5 which
normally oscillates at a frequency of 2800 cycles and
is keyed on and off by relay 6K6 to transmit the
fault tone pulses. Oscillator 6V5 can also be shifted
to a frequency of 285 cycles by the operation of
calling pushbutton 6S1. Transmission of this 285
cycle tone activates buzzers in all other service units
of the system, and is used as a ringing signal to
attract the attention of the other operators. The
output of the service telephone plugged into jack
6J2 is amplified by the 6V4B audio stage and is
passed together with the ring or fault tone through
filter 6FL2 to the communication channel of the
relay system. The voltage level to filter 6FL2 from
fault oscillator 6V5 is set by OSC OUTPUT con-
trol 6R44 and from service telephone amplifier
6V4B by MIKE OUTPUT control 6R49.
6J3 6FL2
6V4 STK NO. 6J2
30075
6R44 6SI STK NO. 6R49 ,,6V5 61(10
54521
6KI
6S2
6T2
6J9
6JI0
6JI2
6113
Figure RS-1?Repeater Service Unit?Front View
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
5 RS-3
RECEIVER, E-W
MODULATOR
SERV. CH.
OUTPUT
SERV, CHAN.
HANDSET
W-2 ?.4
GAIN
CONTROL
RECUR.- MOD.
OR 8.8. AMP.
SERV. CHAN.
INPUT
P.141700.0
GAIN F.
ONTROL
3 KC
LOW PASS
PILTER
(RING)
285
CYCLE
SELECTOR
SIGNAL
RELAY
SIGNAL
BUZZER
TAP GAIN
CONTROL
GAIN
O OLH
(FAULT)
2800
CYCLE
SELECTOR
LOCK
OUT
RELAY
HOLD
OUT
CIRCUIT
AMPLIFIER 14_ GAIN
CONTROL
TAP GAIN
CONTROL
AMPLIFIER
3 KC
LOW PASS
FILTER
GAIN
? 1......_CONTROL
FROM
FAULT'
RELAY E-W TRANS.
205/2800
FAULT
RELAY W-E TRANS
CYCLE
OSCILLATOR
CODER
SENSING
RELAYS
E-W REGVR.
RELAY
( W-E REGVR.
SIGNAL
PUSH
BUTTON
TEST
PUSH
BUTTON
--I RELAY diI--?--EXTERNAL
.011
RELAY
REL AY
EXTERNAL
EXTERNAL
"6"
Figure RS-2?Repeater Service Unit?Block Diagram
In the receiving section the fault/ring tone and
voice frequencies (300 cycles to 3000 cycles) are
received from both the E-W and W-E receivers and
passed through a 3000 cycle low pass filter 6FL1 to
prevent any multiplex frequencies above 3000 cycles
from entering the service unit circuits. W-E INPUT
gain control 6R5 and E-W INPUT gain control 6R6
control the voltage level to filter 6FL1 from the W-E
and E-W receivers respectively. One circuit fed by
this filter is amplifier 6V1, selective to the 285 cycle
ring tone, and gate tube 6V2A which controls relay
6K9. This circuit operates a buzzer when a ring
tone (285 cycles) is present in the service signal.
A second branch of the receiving section consists
of the fault amplifier 6V3, responsive to the 2800
cycle fault tone, gate tube 6V2B and relay 6K8. Re-
ception of a 2800 cycle signal causes relay 6K8 to
operate, opening contact 6K8C which prevents the
starting of motOrs 6M1 and 6B1 and consequent
fault tone transmission from the station. Since as
many as 15 repeater stations may be cascaded in a
section of a system it is possible that two or more
may attempt to transmit fault signals at the same
time. This would result in the appearance of in-
correct information at the terminal station. Relay
6K8 therefore prevents a repeater station from start-
ing a fault transmission when any other repeater
station is sending a fault tone. In addition relay
contact 6K8A by connecting capacitors 6C9A and
6C9B to the 6V2 grid, delays the release of 6K8 for
a sufficiently long time to permit the repeater sta-
tion firs sending the fault tone to complete its fault
transmission before another station starts its own
fault transmission.
The final element of the receiving branch is a
cathode follower stage which amplifies the voice
frequencies to jack 6J2 for the telephone handset
receiver. The handset signal level is set by HAND-
SET VOLUME control 6R11.
Bridge audio jack 6J12 and bridge fault jack 6J13
are provided to accommodate the addition of a
Service Channel Bridging Unit at junction stations.
The service channel bridge permits the use of only
one repeater service unit to serve both stations of
the junction. Jacks 6J12 and 6J13 provide the
means of supplying the fault/ring tones, voice
signals and fault code information to the bridging
unit and of receiving local fault information from
the bridging unit.
CONTROLS
a. The E-W INPUT and W-E INPUT controls
(6R6 and 6R5) vary the amplitude of the service
channel input to filter, 6FL1, from the E-W and W-E
receivers.
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
ffiRS-4
b. The HANDSET VOLUME control (6R11)
varies the amount of voice signal voltage applied
to the grid of handset amplifier 6V4A.
c. The HANDSET jack (6J2) is for connecting
the service channel telephone handset.
d. The OSC OUTPUT (6R44) screwdriver
control adjusts the level of the ring/fault tone
oscillator output fed to low pass filter 6FL2.
e. The MIKE OUTPUT screwdriver control
(6R49) adjusts the gain of microphone amplifier
6V4B.
f. The CALLING pushbutton (6S1) when
pressed changes oscillator 6V5 from a fault tone
(2800 cycle) generator to a ring tone (285 cycle)
generator and connects this fault ring tone signal to
the low pass output filter 6FL2.
g. The TEST pushbutton (6S2) when pressed
causes motors 6M1 and 6B1 to run so that the op-
eration of the fault code circuits may be checked
h. The Variable Tap Resistor, 6R53, reached
from the rear of the unit, controls the amount of
dc voltage for energizing relays 6K1 and 6K10.
i. The Fault Oscillator Control 6R37 is a screw
driver adjusting variable resistor, reached from the
rear of the unit, for setting the frequency of
oscillator 6V5 to the fault tone frequency of 2800
cycles.
j. The Ring Oscillator Frequency Control 6R41
is a screw driver adjusting variable resistor, reached
from the rear of the unit, for setting the frequency
of oscillator 6V5 to the tone frequency of 285
cycles. The adjustment is made with the CALLING
button pushed.
k. The INPUT pinjack (6J1) is for connecting
test leads to a Ballantine Model 300 voltmeter to
measure the audio signal voltage output of filter
6FL1.
1. The OUTPUT pinjack (6J11 ) is for connect-
ing test leads to a Ballantine Model 300 voltmeter
to measure the audio signal voltage output of the
fault/ring tone oscillator 6V5 and microphone
amplifier 6V4B.
STK. NO. STK. NO.
95342 STK. NO 95343 64(6
95344 6K5
TB2
0-1 6R9 1-0
0-113654 H)
? 011111 ?
0-16613 1-0
0-16 R101-0
0-113R 561-0
0-16 IR 57 1-0
0-46R14 1-0
o--16a171-0
? ESA ?
? 11113 ?
eci )-4)
0-4ecl2 I-0
? ELM. ?
0-Cfni-0
o-I6c15 1-0
6J11 6J5
6J4 6J6
TB
0-riiPS51-0
0-16622 1-0
0-161721 1-0
0-1617281-0
0-11512271-0
76566
0-1 6C4 1-0
(3-11TiT1-0
eFo-nWn--o
6JI3
6J12
64( I I 64(4 611 64(10
652 64(3 64(1 61253 61449 6S1
61444
6R37
6RI I 6J8
61230 6L2 6J3
6J7
Figure RS-3?Repeater Service Unit?Rear View, Dust Cover Removed
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
!k
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
MAINTENANCE
General Notes
fault Relay and Commutator
a. At each routine repeater station inspection,
check the operation of the timer motor 6M1 and
6B1 and the commutator brush arm. The timer
should take four minutes and the commutator
brush arm should take 12 seconds to complete one
revolution. When the commutator brushes pass
segment "Z" on the commutator, 6K6 should be
operated.
b. When faulty commutator contact becomes
evident increase the commutator brush pressure as
follows:
Loosen the screw holding the brush arm and
rotate the arm in the direction that will increase the
pressure of the brushes against the commutator
plate and then tighten the arm in this position.
Be certain that the pressure of the brushes against
the segments is sufficient to .make positive contact.
c. A check of the proper operation of the com-
mutator assembly 6E1 in conjunction with the
terminal fault indicating equipment may be made
by simulating each of the five types of faults at
the repeater and observing the lamp panel at the
terminal station for the proper identifying code.
The faults can be simulated by pressing the armature
of each of relays 6K1, 610, 6K4, 6K5, 6K10 and
eRS-5
6K11 in turn. Use the maintenance telephone
channel for checking the results of the test at the
terminal station.
d. Adjust variable resistor 6R53 for a voltage
at 6K1 of 113 v with both transmitter output meter
relays (1M2) in the condition of having their red
and black arms touching (contacts closed).
Input Circuit
a. The normal adjustment of the W-E and E-W
INPUT controls, 6R5 and 6R6, is the maximum
clockwise position.
b. Excess gain is available in both the calling
amplifier and fault amplifiers. If the input voltage
to these circuits is too great the connections to the
6R9, 6R54 and 6R5.5 or the 6R10, 6R56, 6R57
resistance networks may be reduced to a lower tap.
The input voltage to the calling amplifier will
need to be reduced if the voice signals in the
maintenance channel causes the call buzzer to
sound.
c. Adjust the HANDSET VOLUME control to
the desired listening level.
Output Circuit
The adjustment of the level of the fault and
service signals applied to the baseband or receiver/
modulator units from the repeater service unit is
described as follows:
TYPICAL REPEATER SERVICE UNIT VOLTAGES
The following are typical voltages between various tube pins and ground as read with a vacuum tube volt-
meter. All voltages are dc unless otherwise noted.
Tube
Type
Function
Pin
#1
Pin
#2
Pin
#3
Pin
#4
Pin
#5
Pin
#6
Pin
#7
Pin
#8
Pin
#9
6V1
12AX7
Calling Amp.
250
0
2.5
0
0
150
1.0
2.5
6.3
ac
6V2
12AT7
Calling Gate
Fault Lockout
250 '
0
8.4
0
0
250
1.0
8.4
6.3
ac
6V3
12AX7
Fault Amp.
250
0
2.0
0
0
?
?
?
6.3
ac
6V4
12AT7
Handset - Mike
Amp.
250
0
4.0
0
0
80
0
1
6.3
ac
6V5
6AI-16
Osc.
0
1.9
6.3
6.3
150
150
1.9
?
?
ac
ac
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
RS-6
Drop Repeater Station
a. The OSC OUTPUT and MIKE OUTPUT
adjustments are made as follows:
1. Connect an audio voltmeter (Ballantine
Model 300 or equivalent) to pin 6J8-2 and ground.
2. Press the CALLING button and adjust
the OSC OUTPUT control for a meter reading of:
(a) 1.32 volts when used with Baseband Unit
MI-31493.
(b) 0.325 volts when used with Baseband Unit
MI-31120 or MI-31910.
3. Speak into the handset microphone and
adjust the MIKE OUTPUT control for a meter
reading of from:
(a) 0.5 to 0.8 volts when used with Baseband
Unit MI-31493.
(b) 0.12 to 0.2 volts when used with Baseband
Unit MI-31120 or MI-31910.
b. At stations where Baseband Unit MI-31493 is
used, the repeater service unit output connection is
REPLACEMENT
to be made at the junction of 6R63 and the "OUT"
terminal of 6FL2. At stations where Baseband Unit
MI-31120 or MI-31910 is used, the repeater service
unit output connection is to be made at the junction
of 6R63 and 6R62. The specified levels cannot be
obtained if the wrong output connection is used.
Thru Repeater Station
a. The OSC OUTPUT and MIKE OUTPUT
adjustments are made as follows:
1. Connect the audio voltmeter (Ballantine
Model 300 or equivalent) to pin 638-2 and ground.
2. Press the CALLING button and adjust the
OSC OUTPUT control for a meter reading of
0.057 volt.
3. Speak into the handset microphone and
adjust, the MIKE OUTPUT control for a meter
reading of from 0.023 to 0.035 volt on voice peaks.
b. The audio output connection must be made
at the junction of 6R59 and 6R62. Severe overload-
ing of the modulator will result if the wrong out-
put connection is used.
PARTS LIST
Symbol No.
Description
Drawing No.
Stock No.
6B1
Motor, synchronous, clock type, 115 v., 60 cycle
8833318-1
95340
6C1 to 6C4
Capacitor, fixed, mica, 560 mmf -?2%, 500 v.
722022-553
72841
6C5
Capacitor, fixed, paper, 0.1 mf -?10%, 400 v.
735715-175
73551
6C6
Capacitor, fixed, paper, 0.47 mf -?2096, 200 v.
735715-33
73787
67
Capacitor, fixed, mica, 9100 mmf -.1-2%, 300 v.722029-562
95383
6C8
Capacitor, fixed, mica, 10,000 mmf -?200/c, 300 v.
727865-71
92036
6C9A, B
Capacitor, fixed, paper, 4.0 mf +20 ?10%, 100 v.
8887709-153
95341
6C10
Capacitor, fixed, paper, 0.1 mf -?10%, 400 v. Same as 6C5
735715-175
73551
6C11
Capacitor, dry electrolytic, 10 mf, 25 v.
442901-46
52533
6C12 to 6C14
Capacitor, fixed, mica, 220 mmf -.?2%, 500 V.
727853-331
71014
6C15
Capacitor, fixed, paper, 0.1 mf 1.-10%, 400 v. Same as 6C5
735715-175
73551
6C16
Capacitor, dry electrolytic, 10 mf, 25 v. Same as 6C11
442901-46
52533
6C17
Capacitor, fixed, paper, 0.01 mf -?10%, 400 v. .
735715-163
73561
6C18
Capacitor, fixed, paper, 0.1 mf -...I:10%, 400 v. Same as 6C5
735715-175
73551
6C19
Capacitor, fixed, paper, 0.47 mf -.?20%, 200 v. Same as 6C6
735715-33
73787
6C20
Not used.
6C21
Capacitor, fixed, mica, 2200 mmf -_1:10%, 500 v.
727866-155
39660
6C22
Capacitor, fixed, ceramic, 1500 ma +100 ?0%, 500 v.
449696-3
73748
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
/5 RS-7
Symbol No,
Description
Drawing No.
Stock No.
6E1
Commutator Assembly?(following parts only available)
744080-$02
Clip, contact brush holding clip (Part of 6E1)
128727-1 .
95344
Contact, sliding, for code signal commutator assembly (Part of 6E1)
1287464
95343
Plate, repeater code signal commutator plate assembly, complete with
contacts and terminals (Part of 6E1)
458943-502
95342
6FL1
Filter, low pass, 3.6 to 100 kc/s impedance 5000 ohm input and output
8833307-2
95345
6FL2
Filter, low pass, 3.6 to 100 kc/s impedance 10,000 ohm input and output
8833306-2
95346
611
Buzzer, door bell type, 8-12 v., 60 cycle
8848315-3
95347
,
631
Connector, female, pin jack ,
742565-1
93678 '
632
Connector, female, telephone jack
8845648-1
94232
633
Connector, male, 6 contact, chassis mtg.
181494-3
28507
634 to 637
Connector, female, 6 contact, chassis mtg.
181494-4
18534
638
Connector, male, 6 contact, chassis mtg. Same as 633
181494-3
28507
639
Connector, female, 6 contact, chassis mtg. Same as 634
181494-4
18534
6J10
Connector, male, 6 contact, chassis mtg. Same as 633
181494-3
28507
6J11
Connector, female, pin jack. Same as 6J1
742565-1
93678
6312
Connector, male, 6 contact, chassis mtg. Same as 6J3
181494-3
28507
6313
Connector, female, 6 contact, chassis mtg. Same as 634
181494-4
18534
61(1
Relay, dc, coil, 68 v., 3 form "A" make, contacts
174913-8
95348
6K2
Not used.
61(3
Relay, ac, midget type, coil, 115 v., 50/60 cycle, 3 p.s.t. normally open
contacts
458952-2
95349
6K4 to 6K7
Relay, ac, midget type, coil, 115 v., 50/60 cycle, d.p.d.t. contacts ..
458952-1
95350
61(8
Relay, dc, coil, 72 v., 2 form "C" break-make contacts
174913-7
95351
61(9
Relay, dc, coil, 41 v., 1 form "C" break-make contact
174913-6
95352
61(10
Relay, dc, coil, 68 v., 3 form "A" make contacts. Same as 6K1
174913-8
95348
61(11
Relay, ac, midget type, coil, 115 v., 50/60 cycle, d.p.d.t. contacts. Same
as 61(4 ?
458952-1
95350
6L1
Reactor, iron core, 350 mh at 35 ma
8833309-1
95359
6L2
Reactor, air core, r-f choke, 21 microhenry, 600 ma, 20-60 mc
8896181-1 .
57918
6M1
Motor, timer, clock type, 115 v., 60 cycle, with one s.p.d.t. microswitch
attached and fixed cam with 60 notch
458949-1
95360
6R1, 6R2
Resistor, fixed, composition, 3900 ohm -?1096, 1/2 w.
735730-69 .
502239
6R3, 6R4
Resistor, fixed, composition, 4700 ohm -2-.40%, V2 w.
735730-70
502247
6R5, 6R6
Resistor, variable, composition, 5000 ohm -2:1096, 2 w
737829-30
94039
6R7, 6R8
Resistor, fixed, composition, 5600 ohm -2:10%, V2 Nv-
735730-71
502256
6R9, 6R10
Resistor, fixed, composition, 4700 ohm -?10%, 1/2 w. Same as 6R3 .
735730-70
502247
6E11
?
Resistor, variable, composition, 10,000 ohm -2:10%, 2 w.
737801-43
205064
6R12
Resistor, fixed, composition, 1500 ohm ?10%, 1/2 w.
735730-64
502215
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6 .
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
J3 RS-8
Symbol No.
Description
Drawing No.
Stock No.
6R13
Resistor, fixed, composition, 1000 ohm ?1096, ;oi w.
735730-62
502210
6R14
Resistor, fixed, composition, 1 meg --t.-5%, 1/2 w.
735730-231
? 502510
6R15
Resistor, fixed, composition, 270,000 ohm -L-10%, 1/2 w.
735730-91
502427
6R16 to 6R19
Resistor, fixed, composition, 1 meg -?5%, 1/2 w. Same as 6R14
735730-231
502510
6R20, 6R21
Resistor, fixed, composition, 56,000 ohm -?10%, 2 w.
99126-83
522356
6R22
Resistor, fixed, composition, 1000 ohm J.:5%, 1 w
90496-159
512210
6R23
Resistor, fixed, composition, 1500 ohm ?-10%, 1/2 w. Same as 6R12
735730-64
502215
6R24
Resistor, fixed, composition, 33,000 ohm -L-10%, 1/2 w.
735730-80
502333
6R25
Resistor, fixed, composition, 390,000 ohm -?1096, 1 w.
90496-93
512439
6R26
Resistor, fixed, composition, 2.7 meg ?10%, 1/2 w
735730-103
72788
6R27
Resistor, fixed, composition, 1000 ohm -?596, 1 w. Same as 6R22
90496-159
512210
6R28, 6R29
Resistor, fixed, composition, 56,000 ohm -1:10%, 2 w. Same as 6R20.
99126-83
522356
6R30
ikesistor, fixed, composition, 4700 ohm -L-1096, 1/2 w. Same as 6R3
735730-70
502247
6R31
Resistor, fixed, composition, 270 ohm :1--10%, 1/2 w.
735730-55
502127
6R32
Not used.
6R33
Resistor, fixed, composition, 39,000 ohm -L-1096, 1 w?
90496-81
512339
6R34
Resistor, fixed, composition, 180 ohm -L-10%, V2 w?
735730-53
502118
.
6R35
Resistor, fixed, composition, 12,000 ohm -?5%, 2 w.
99126-185
522312
6R36
Resistor, fixed, composition, 22,000 ohm -1-.5%. 1/2 w
735730-191.
502322
6R37
Resistor, variable, composition, 500,000 ohm ?-10%, 2 vv.
737854-5
95368
6R38
Not used.
6R39, 6R40
Resistor, fixed, composition, 100,000 ohm -?-5%, 1/2 w
735730-207
502410
6R41
Resistor, variable, composition, 2.5 meg., -L-10%, 2 w.
737885-12
97031
6R42, 6R43
Resistor, fixed, composition, 1.2 meg., -?-5%, v2 w.
735730-233
502512
6R44
Resistor, variable, composition, 200,000 ohm -?10%, 2 w.
737854-6
95369
6R45
Resistor, fixed, composition, 22,000 ohm -L-10%, 1/2 w.
735730-78
502322
6R46
Resistor, fixed, composition, 47,000 ohm -?-10%, 1/2 w.
735730-82
502347
6R47
Resistor, fixed, composition, 220 ohm -?10%, 1/2 w. . .. .
735730-54
502122
6R48
Resistor, fixed, ccinposition, 150,000 ohm -L-10%, 1/2 w.
735730-88
502415
6R49
Resistor, variable, composition, 500,000 ohm -L-1096, 2 w.
737854-5
95368
6R50
Resistor, fixed, compositicn, 39,000 ohm -?1070, 1 w. Same as 6R33 .
90496-81
512339
6R51
Not used.
6R52
Not used.
6R53
Resistor, adj. wire wound, 10,000 ohms -L-10%, 25 w.
44%95-6
202931
6R54
Resistor, fixed, composition, 4700 ohm ?10%, 1/2 w. Same as 6R3
735730-70
502247
6R55
Resistor, fixed, composition, 5600 ohm -?10%, 1/2 w. Same as 6R7
735730-71
502256
6R56
Resistor, fixed, composition, 4700 ohm -.1-10%, 1/2 w. Same as 6R3 .
735730-70 .
502247
6R57
Resistor, fixed, composition, 5600 ohm -L-10%, 1/2 w. Same as 6R7 .
735730-71
502256
6R58
Resistor, fixed, composition, 150 ohm -?-100/0, 1/2 w.
715730-52
502115
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
RS-9
Symbol No.
Description
Drawing No.
Stock No.
6R59
Resistor, fixed, composition, 470 ohm ?10%, 1/2 w.
735730-58
502147
6R60
Resistor, fixed, composition, 1000 ohm 104/6, 46 w. Same et 6R13 .
735730-62
502210
6R61
Resistor, fixed, composition, 1000 ohm 1;1096, 1/2 w. Same as 61113?
735730-62
502210
6R62
Resistor, fixed, composition, 1500 ohm -?10%, 1/2 w. Same as 6R.12
735730-64
502215
R63
Resistor, fixed, composition, 10,000 ohm ?-10%, 1/2 w.
735730-74
502310
. SI
Switch, push leaf type, non-locking, 3 break, 1 make contacts with
black bakelite button
458953-3
95370
S2
Switch, push leaf type, non-locking, break-make contact, with black
bakelite button
458953-1
95386
S3
Switch, snap action, bakelite case, s.p.d.t. contacts (Part of 6M1)
8810605-1
97447
6T1
Transformer, bell ringing
458947-1
95371
6T2
Transformer, filament
949385-1
94196
6X1 to 6X4
Socket, tube, 9 pin miniature
984055-2
94880
6X5
Socket, tube, 7 pin miniature
737867-18
94879
Miscellaneous
Knob, round bakelite (for 6R11)
712336-507
30075
Lubricant, 5/8 oz. vial of molycote, type Z
891997-33
208040
?
Screw, thumb, brass, back cover holding8886111-2
94391
Shield, tube, 7 pin miniature type
99369-2
54521
Shield, tube, 9 pin miniature type
8858642-3
56359
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
WE INPUT
612I E.R5 Gr.R3
3900 5000 4700
5600
6R 7
6RB
5600
SEE
NOTE
.3
6F LI
IN OUT
CR2 6RE, GR4
3900 5000 4700
EW 11-,puT
BRIDGE AsiDi0
6JI2`
5
SEE NOTE
CALLING
12A27
4700
P 9
6R 54
4700
INPUT
6R5 5
5600
6 RIO
4700
GR 56
4700
CALL INS GATE
I2AT7
GRI5
70K
4
FAULT
MPL
I 2 AX7
4
1
GCS 6C6 A._ -
A 0.4.710T
tlimF
6CI ."-'; :2
:F --I f--
6R16 560 560 6pr, I 7
i MEG
8 10001 I ksE
6R18
9
GRI2 -r546.?C41
500
6Ri3 16,1)114 L - 56?7'
IV\NO- _ I MEN ?
G
OO
IME
CRI9
MEG
r
4 5
9
c-AL,LT LO:..FOUT GATE
AL'
350mH
64V s
6C7
9100
6C8
?11
.01 MF
GCI9
0.4 7MF
2R363
Vv?
150
3
4 5
91
3
6R21
4-'s."\n/-4
58K
6c/22
11000
GK8
- -1- ?
X./V 2-8 I
_
A 1
0+
b 6R2e
-?-?W
? 56R29
6K
GQ9A{ GC9 V\
56K
4NF 4MF
OSC
641-16
6R35
6R33
39K 6X/V5
I2K
4, P57
5600
6R 23
,500
6R26 G,R27
47 1000
MEG
HANDSET AMPL
12AT-7
GR25
390K
35K
HANDSET Gx/V4-A
VOLUMESEE4OTE6Ril HANDSET
41.7ROC, SI
6R 31 6
10K
6c12
600
TO.TMF
4 3
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Figure RS-4?Repeater Service Unit?Schematic Diagram
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
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Figure RS-5--Repeater Service Unit-Wiring Diagram
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6 _
MICROWAVE COMMUNICATION EQUIPMENT
utt, 1 Serico V rit
llQ lad 112E- 14101
? TECHNICAL DATA
? DESCRIPTION
? MAINTENANCE
? REPLACEMENT PARTS
RADIO CORPORATION OF AMERICA
COMMERCIAL ELECTRONIC PRODUCTS, CAMDEN, N. J.
Printed in U.S.A. 18-33232-2
DU 566 ? 567
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
0
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
NOTICE
This Instruction Book, IB-33232-2, contains in-
structions for Terminal Service Unit MI-31496 and
MI-31496-A. Although the material is presented
in terms of MI-31496 the information contained
in this book pertains to both MI-31496 and
MI-31496-A except where noted.
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6 c TS-1
TECHNICAL DATA
Power input:
a. Filament Heaters: 14 watts at 115 v, 50/60 cycles ac
b. Plate Supply: 70 milli:Imps at 250 v dc
Levels:
a. Transmitting Amp.:
Input: Telephone handset
Output: 6 v (approx.) rens across 60,000 ohms
b. Receiving Amp.:
Input: 5 v (approx.) runs across 10,000 ohms
Output: Handset
Ringing Frequency:
285 cycles
Fault Signal Frequency:
2800 cycles
Tube Complement:
Symbol Type
7V1 12AX7
7V2 12AT7
7V3 12AX7
7V4 12AT7
7V5 6AH6
7V6 OB2
Weight and Dimensions:
Weight: 16 lbs.
Height: 83,4"
Depth back of panel:
Depth front of panel:
Width: Standard 19"
Function
Calling Amplifier
Calling Gate and Fault Gate
Fault Amplifier
Handset Amplifier and Mike
Amplifier
Ring/Tone Oscillator
Voltage Regulator
41/2"
4"
Rack Mounting
DESCRIPTION
The Terminal Service Unit MI-31496 is designed
for mounting in either a standard 19" open rack or
cabinet and is installed in any station where station
fault identification is required. It contains the fa-
cilities for indicating the fault signals transmitted
from the repeater stations. A lamp panel indicates
which station is sending the fault signals and the
nature of the trouble. It is possible to identify up to
five faults from any one repeater station. It also in-
dicates the failure of the terminal transmitter or re-
ceiver. The unit also contains the voice channel
equipment for party line ringing and conversation
with the repeater stations.
Service channel signals (fault tone, ring tone and
voice signals-300 cycle to 3kc) from the repeater
service units located at the unattended repeater sta-
tions are transmitted along with the multiplex sig-
nals and when received at the terminal are separated
from the multiplex signals and channelled to the ter-
minal service unit. These service channel signals
are first passed through filter 7FL1 which serves to
eliminate any frequency higher than 3000 cycles
which may be present due to multiplex transmission
along the system. The signal voltage input to filter.
7FL1 is adjusted by means of INPUT CONTROL
7R1. The signals from 7FL1 feed through separate
audio amplifier circuits. One circuit, consisting of
calling amplifier 7V1 and calling gate 7V2A, is a
selective amplifier and gate tube tuned to 28.5 cycles,
the ring tone signal frequency. Its selective circuit
consists of a parallel "T" bandstop filter as a feed
back element for the second section of the 12AX7
twin triode (7V1). The presence of a 285 cycle
ring tone pulse in the input of this calling circuit
energizes relay 7K1 in the plate circuit of calling
gate 7V2A which operates buzzer 7113 thereby at-
tracting the attention of the operator or mainte-
nance man. This alerts the terminal station per-
sonnel that a party line call is being made from
another station. The party line voice signals of the
service channel from filter 7FL1 are amplified by the
cathode follower circuit of 7V4A before passing to
the receiver of the telephone handset MI-31019-A
plugged into jack 7J2. Handset volume control
7R21 sets the level of voice signals to the handset.
The presence of fault tone signals at 2800 cycles
in the output of 7171.1 will activate the circuit con-
sisting of fault amplifier 7V3 and -fault gate com-
prised of gate tube 7V2Il and relay 7K2. A 2800
cycle fault tone pulse will cause a large voltage to
be developed in the plate circuit of amplifier 7V3
by the high impedance of the parallel circuit com-
posed of reactor 7L1 and capacitor 7C7 resonant at
2800 cycles. This voltage applied to the grid of
7V2B, which is normally biased at cutoff, will cause
plate airrent to flow and energize relay 7K2. Thus
on the arrival of a fault tone signal from one of the
repeater stations, relay 71(2 will close its contacts
7K2A, 7K2B and 7K2C which cause the following
action to ensue: Relay contact 7K2B will energize
relay 7K3 and close contact 7K3A which operates
buzzer 7113 to attract the attention of the operator.
Approved For Release 2091/03/04: CIA-RDP79T01049A002600030004-6
CI1S-2 Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
7J8 7JI 7V.1
7F LI
STK
56333
7FL 2
7L1 71 GAIN
SERV. CHAN. CONTROL
OUT
SERV. CHAN.
HANDSET
GAIN
CONTROL
RECEIVER -
MODULATOR
OR
BASEBAND AMP.
SERV. CHAR.
I NPUT
?3 KC
LOW
PASS
FILTER
AMPLIFIER 14 GAIN
CONTROL
MICROPHONE
AMPLIFIER
3 KC
LOW PASS
F ILTER
(R I NG)
TAP
GAIN
CONTROL
285
CYCLE
SELECTOR
SIGNAL
RELAY
7KI
SIGNAL
BUZZER
(FAULT)
2800
CYCLE
SELECTOR
RELAY
7 K 3
I A
2B
3C
4 '
ST
BR
LAMP
BANK
FROM
TRANS.
AND
REC.
FAULT
SENSING
RELAYS
TAP
GAIN
CONTROL
RELAY
7 K 2
FA ULT
DECODER
285
C YC LE
OSCILLATOR
SIGNAL
PUSH
BUTTON
TEST
PUSH
BUTTON
4
11-149598*1
Figure TS-2?Terminal Service Unit?Block Diagram
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
C? TS-4 Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
nolocked so that the needle will be free to rise when
the transmitter is again operating. A single push
of buzzer release 7S4 with switch 7S5 closed will
not keep 7K3 released because local faults en-
ergizing 7K5 or 7K6 are continuing voltages and
.not coded pulses. With 755 closed BUZZER RE.
LEASE 7S4 must be held as long as the local fault
lasts to keep the buzzer silenced. After a local
fault has caused an indicator lamp to be lit and the
buzzer to sound, opening TERMINAL FAULT
switch 7S5 will permit the light to be extinguished
and allow the buzzer to be silenced when the LIGHT
RELEASE button and the BUZZER RELEASE
button are pressed. Control 7R56 is set at 113
volts when 1M2 and 7K6 are operated.
In the transmitting portion of the unit, the 285
cycle ring tone signal for calling the repeater sta-
tions is produced in audio oscillator 7V5 and is
transmitted whenever calling button 7S1 is pressed.
The voice frequencies from the service channel tele-
phone handset are amplified in 7V4B. Both the
voice and ring tone signals are passed through filter
7FL2 before delivery to the baseband unit. The
amplitude of ring tone and voice signals are regu-
lated by oscillator output control 7R32 and micro-
phone output control 7R35 respectively. Filter
7FL2 is a low-pass filter which prevents transmis-
sion of any signals having frequencies higher than
3000 cycles which would interfere with the multi-
plex carrier channels.
CONTROLS
a. The INPUT CONTROL (7R1) , varies the
amplitude of the service signal input to the 3000
cycle low-pass filter 7FL1,
b. The INPUT pinjack (7J1) is for connecting
test leads to a Ballantine Model 300 voltmeter to
measure the audio signal voltage output of filter
7FL1.
c. The OUTPUT pinjack ( 7J8) is for connect-
ing test leads to a Ballantine Model 300 voltmeter
MAI NTE
General Notes
Fault Indicating Section
a. A test of the condition of the neon bulbs of
the lamp indicating panel and the operation of
the commutator assembly should be made daily.
Press LIGHT TEST switch, 7S3, and hold depressed.
Ensure that the lamps come on in the following
order: 1, A, 2, B, 3, C, 4, D, 5,-6. The lamps R and
T should come on immediately when 7S3 is de-
pressed. Continue to hold 7S3 depressed and when
to measure the audio signal voltage output of the
ring tone oscillator 7V5 and microphone amplifier
7V4B.
d. The HANDSET VOLUME control (7R21)
varies the amount of voice signal voltage applied
to the grid of handset amplifier 7V4A.
e. The HANDSET jack (732) is for connecting
the service channel telephone handset.
f. The OSCILLATOR OUTPUT screwdriver
control (7R32) adjusts the level of the ring tone
oscillator output fed to low-pass filter 7FL2.
g. The MIKE OUTPUT screwdriver control
(7R35) adjusts the gain of microphone amplifier
7V4B.
h. The CALLING pushbutton (7S1) when
pressed connects the output of the ring tone oscil-
lator (285 cycles) to the service channel output of
the unit. This signal energizes the buzzers at all
other stations.
i. The TERMINAL FAULTS switch (7S5)
breaks the energizing circuit of both relays 7K5 and
7K6 to allow the (T) and/or (R) fault lamps to
be turned off by pressing the LIGHT RELEASE
button and to allow the alarm buzzer to be quieted
by pressing the BUZZER RELEASE button.
j. The BUZZER RELEASE (7S4)? when pressed
opens the 7K3 relay circuit breaking the 115 v ac
circuit to the buzzer causing it to stop operating.
k. The LIGHT RELEASE (7S2) when pressed
closes the circuit of relay 7K4 which opens a contact
that wipes off any previous lamp indications show-
ing on the lamp indicator panel.
1. The LIGHT TEST pushbutton (753) when
pressed runs the fault commutator motor through its
cycle causing the indicator lamps to light in
sequence and reveal any neon bulb not operating.
7S3 must be held in for the duration of the test.
m. The RING TONE OSCILLATOR frequency
control 7R29 is a screwdriver adjustable poten-
tiometer, reached from the rear of the unit, for set-
ting the frequency of the oscillator 7V5 to the ring
tone frequency of 285 cycles.
NANCE
the commutator starts on its second revolution en-
sure that relay 7K4 extinguishes all the lamps, and
that they relight in the above order. Release 7S3
when the lamp, "6" comes on, and the commutator
brush arm will come to rest in its stop position.
Press LIGHT RELEASE switch, 7S2, and ensure that
all lamps are extinguished.
b. Before replacing a lamp that fails to light it
should first be determined if the commutator is at
fault. A bad commutator brush contact or dirty
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
? Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6 QTS-5
segment may cause a bulb not to light or it may
cause loss of synchronism between the repeater and
terminal commutator brush arms which will give
a false indication. If faulty brush contact causes
trouble, this can be corrected by performing the fol-
lowing adjustment:
Loosen the screw holding the brush arm and
rotate it in the direction that will increase the
pressure of the brushes against the commutator
plate and then tighten the arm in this position.
Be sure that the pressure of the brushes against
the segments is sufficient to make positive contact.
c. Check-the action of the receiver fault relay.
7K5 by removing 2V1 the first i-f tube of the
receiver/modulator. (Be certain that the TERMI-
NAL FAULTS switch 7S5 is in the ON position.)
This will energize relay 7K5, which, if operating
normally, will cause the buzzer to sound and light
indicator lamp R. After replacing 2V1, press the
LIGHT RELEASE switch 7S2 to check the operation
of light release relay 7K4. Lamp R should be ex-
tinguished. Also press the BUZZER RELEASE
switch 7S4 to silence the buzzer.
Input Circuit
-a. See that the INPUT CONTROL 7R1 is
turned to the maximum clockwise position.
b. If the calling buzzer has a tendency to sound
when voice signals are being received, the input
voltage to calling amplifier 7V1 must be reduced
by moving the grid input connection to the next
lower tap of the 7R3, 7R58, 7R59 resistance network.
c. The normal connection to the control grid
of fault amplifier 7V3 is at the junction of 7R15 of
the resistance network and 7J1 as shown on the
terminal service unit schematic. If voice signals
cause the commutator brush arm to turn, and cause
the lamps to light, the fault amplifier gain can be
reduced by moving the control grid connection to a
lower tap on the 7R15, 7R60, 7R61 network.
d. Adjust the HANDSET VOLUME control to
the desired listening level. ?
e. To check the proper operation of relays 7K1
and 7K2 and the amplifier circuits associated with
them, send out a calling tone and a simulated fault
tone from a repeater station and observe whether
or not the buzzer sounds and the commutator motor
runs.
Output Circuit
a. The adjustment of the level of the service
signals applied to the baseband unit from the ter-
minal service unit is made as follows:
1. Connect an audio voltmeter (Ballantine
Model 300 or equivalent) to pin 7J5-2 and ground.
2. Press the CALLING button and adjust the
OSC OUTPUT control for a meter reading of:
(a) 1.32 volts when used with Baseband Unit
MI-31493.
(b) 0.325 volts when used with Baseband Unit
MI-31120.
3. Speak into the handset microphone and
adjust the MIKE OUTPUT control for a meter
reading of from:
(a) 0.5 to 0.8 volts when used with Baseband
Unit MI-31493.
(b) 0.12 to 0.2 volts when used with Baseband
Unit MI-31120.
b. Adjust 7R56 so that the voltage to 7K6 is
113 v with the transmitter output meter-relay
( 1M2) in the condition of having its red and black
arms touching (contacts closed).
c. At stations where Baseband Unit MI-31493 is
used, the terminal service unit output connection is
to be made at the junction of 7R69 and the "OUT"
terminal of 7FL2. At stations where Baseband Unit
MI-31120 is used, the terminal service unit output
connection is to be made at the junction of 7R69
and 7R68. The specified levels cannot be obtained
if the wrong output connection is used.
TYPICAL TERMINAL SERVICE UNIT VOLTAGES
The following are typical voltages between various tube pins and ground as read with a vacuum tube volt-
meter. All voltages are dc unless otherwise noted.
Tube
Type
Function
Pin
#1
Pin
#2
Pin
#3
Pin
#4
Pin
#5
Pin
#6
Pin
#7
Pin
#8
Pin
#9
7V1
12AX7
Calling Amp.
250
0
2.5
0
0
140
1.0
2.5
6.3 a.c.
7V2
12AT7
Calling, Fault
Gate . . .
248
0
5.9
0
0
250
1.0
8.4
6.3 a.c.
7V3
12AX7
Fault Amp.
250
0
2.0
0
0
-
-
-
6.3 a.c.
7V4
12A'F7
Handset, Mi ke
Amp!. . .
250
0
3.0
0
0
95
0
1
6.3 a.c.
7V5
6A116
Osc
-0.8
1.8
-
6.3 a.c.
150
150
1.8
-
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
C1TS-6
Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
7C5 7R16 7P13 7RI4 7R2 7R19
7R 3 ?RI 7FL I
R18
R20
7 R38
FL 2
7C7
7C3
7C 4
7R10
--7R11
R53
7J 3
7C II
7CI6
J4
7R26
7R62 7RE 4 7C9 /
7R83 7R55 7R56
7R27
7R36 ?R34 7R37
7C17 7R22
7C10 7CI8
Figure TS-3?Terminal Service Unit?Rear View, Dust Cover Removed
7J5
7R 39
71279
7K
7X V3
7 X V2
7J1
7R58
7R 5
7 R 60
7S3 754 7S5
7C12
R 30
7 C13
7 R31
TTI 7R35 7R32 7J2 7XV5 7R2 C14
7 K 2 781 7R29 7R21 7R1 7R64 C15
11293
Figure TS-4?Terminal Service Unit?Rear View, Dust Cover Removed
Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6 C-Ts4
REPLACEMENT PARTS LIST
Symbol No.
Description
Drawing No.
Stock No.
7B1
Motor, synchronous, clock type, 115 v., 60 cycle, 5 rpm, counter
clockwise
88333184
95340
7C1 to 7C4
Capacitor, fixed, mica, 560 mmf -?2%, 500 v.
722022-553
72841
7C5
Capacitor, fixed, paper, 0.1 mf -?100/0, 400 v.
735715-175
73551
7C6
Capacitor, fixed, paper, 0.47 mf -?20%, 200 v.
735715-33
73787
7C7
Capacitor, fixed, mica, 9100 mmf :4:2%, 300 v.
722029-562
95383
7C8
Capacitor, fixed, mica, 0.01 mf -?-10%, 400 v.
727865-71
92036
7C9
Capacitor, fixed, paper, 0.47 mf -2:20%, 200 v. Same as 7C6
735715-33
73787
7C10
Capacitor, fixed, paper, 0.1 mf -?10%, 400 v. Same as 7C5
735715-175
73551
7C11
Capacitor, dry electrolytic, 10 mf, 25 v.
442901-46
52533
7C12 to 7C14
Capacitor, fixed, mica, 1000 mmf ?..2%, 500 v.
722022-559
90003
7C15
Capacitor, fixed, paper, 0.1 mf -?-10%, 400 v. Same as 7C5
735715-175
73551
7C16
Capacitor, dry electrolytic, 10 mf, 25 v. Same as 7C11
442901-46
52533
7C17
Capacitor, fixed, paper, 0.01 mf -.?10%, 400 v.
735715-163
73561
7C18
Capacitor, fixed, paper, 0.1 mf -?10%, 400 v. Same as 7C5
735715-175
73551
7C19
Not used.
7E1
Commutator Assembly?(following parts only stocked)
744080-501
Plate, terminal code signal commutator plate assembly, complete with
contacts and terminals
458943-501
95384
Clip, contact brush holding clip
128727-1
95344
. Contact, sliding, for code signal commutator assembly
128746-1
95343
7FL1
Filter, low pass, 3.6 to 100 kc/s impedance 5000 ohm
8833307-2
95345
7FL2
Filter, low pass, 3.6 to 100 kc/s impedance 10,000 ohm
8833306-2
95346
711 to 7112
Lamp, neon pigtail type
87229144
95385
7113
Buzzer, door bell type 8-12 v., 60 cycle
8848315-3
95347
7J1
Connector, female, pin jack
742565-1
93678
7J2
Connector, female, telephone jack
8845648-1
94232
7J3, 7J4
Connector, female, 6 contact, chassis mtg.
181494-4
18534
7J5
Connector, male, 6 contact, chassis mtg.
181494-3
28507
7J6
?
Connector, female, 6 contact, chassis mtg. Same as 7J3181494-4
18534
7J7
Connector, male, 6 contact, chassis mtg. Same as 7J5
181494-3
28507
7.18
Connector, female, pin jack. Same as 7J1
742565-1
93678
7K1
Relay, dc, coil 41 v., 1 form "C" break-make contact
174913-6
95352
7K2
Relay, dc, coil 68 v., 3 form "A" make contacts
174913-8
95348
7K3, 7K4
Relay, ac, midget type, coil 115 v. 50/60 cycle, dpdt contacts
458952-1
95350
7K5
Relay, ac, midget type, coil 115v., 50/60 cycle, 3 p.s.t., normally open
contacts .
458952-2
95349
7K6
Relay, dc, coil 68 v., 3 form "A" make contacts. Same as 7K2
174913-8
95348
7L1
Reactor, iron core, 350 mh
8833309-1
95359
7R1
Resistor, variable, compositicn, 2000 ohm -.1.7.10%, 2 w.
737829-29
51925
7R2
Resistor, fixed, composition, 2200 ohm -?10%, 1/2 w.
735730-66
502222
7R3
Resistor, fixed, composition, 4700 ohrn ?-10%, 1/2 w.
735730-70
502247
7R4
Resistor, fixed, composition, 1500 ohm ?-10%, 1/2 w.
735730-64
502215
7R5
?
Resistor, fixed, composition, 1000 ohm ?-10%, V2 w.735730-62
502210
7R6
Resistor, fixed, composition, 1. meg J:5% 1/2 w.
735730-231
502510
7R7
Resistor, fixed, composition, 270,000 ohm J:1004, 1/2 w.
735730-91 .
502427
7R8 to 7R11
Resistor, fixed, composition, 1 meg -...t5%, 1/2 w. Same as 7R6
735730-231
502510
7R12
Resistor, fixed, composition, 1000 ohm :0%, 1 w.
90496159
512210
7R13, 7R14
Resistor, fixed, composition, 56,000 ohm -?10%, 2 w
99126-83
28741
7R15
Resistor, fixed, composition, 4700 ohm ?1096, 1/2 w. Same as 7R3
735730-70
502247
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
6,pproved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Symbol No.
Description
Drawing No.
Stock No.
71(16
Resistor, fixed, composition, 1500 ohm -?-10%, 1/2 w. Same as 7R4
735730-64
502215
71(17
Resistor, fixed, composition, 1 meg ??5%, 1/2 w. Same as 71(6
735730-231
502510
7R18
Resistor, fixed, composition, 680 ohm -115%, 1 V.
90496-155
512168
7R19, 71(20
Resistor, fixed, composition, 56,000 ohm ?109(s, 2 w. Same as 71(13
99126.83
28741
71(21
Resistor, variable, composition, 10,000 ohm -?10%, 2 W.
737801-43
68833
7R22
Resistor, fixed, composition, 4700 ohm ?.10%, V2 w. Same as 7113 .. ?
735730-70
502247 ?
71(23
Resistor, fixed, composition, 270 ohm -?.10%, 1/2 V.
735730-55
502127
7R24
Not used.
71(25
Resistor, fixed, composition, 39,000 ohm -1:100/0, 1 w.
90496-81
512339
7R26
Resistor, fixed, composition, 10,000 ohm -1:10%, 2 w.
99126-74
522310
7R27
Resistor, fixed, composition, 150 ohm -.1-1096, 1 w
90496-52
512115
7R28
Not used.
7R29
Resistor, variable, composition, 500,000 ohm ?-10%, 2 w.
737854-5
95368
71(30, 71131
Resistor, fixed, composition, 270,000 ohm ?1096, 1/2 w. Same as 7R7
735730-91
502427
7R32
Resistor, variable, composition, 200,000 ?10%, 2 w:
737854-6
95369
7R33
.ohm
Resistor, fixed, composition, 22,000 ohm zi....10%, 1/2 w.
735730-78
502322
7R34
Resistor, fixed, composition, 47,000 ohm -.?:10%, 1/2 w.
735730-87
502347
71(35
Resistor, variable, composition, 500,000 ohm -?10%, 2 w. Same as 7R29
737854-5
95368
71(36
Resistor, fixed, composition, 150,000 ohm ?1096, 1/2 w.
735731/.88
502415
71(37
Resistor, fixed, composition, 220 ohm ?1096, 1/2 w.
735730-54
502122
7R38
Resister, fixed, composition, 12,000 ohm th-5%, 1/2 w. (for MI-31496
only)
82283-185
502312
7R39
Resistor, fixed, composition, 39,000 ohm ?100/0, 1 w. Same as 71(25
90496-81
512339
7R40 --
Not used.
7R41 to 71(52
' Resistor, fixed, compesition, 82,000 ohm :1:10%, 1/2 w.
735730-85
502382
71(53
Resistor, fixed, composition, 6800 ohm ?:10%, 1/2 w
735730.72
502268
7R54, 7R55
Resistor, fixed, composition, 18,000 ohm ?-10%, 2 w.
99126-77
522318
71(56 I
Resistor, adj. wire wound, 10,000 ohm ?10%, 25 w i
449695-6
202931
71(57
Resistor, fixed, composition, 68,000 ohm -.1:10%, Y2 w.
735730-84
502368
7R58
Resistor, fixed, composition, 4700 ohm ?10%, 1/2 w. Same as 7R3 -
735730-70
502247
71(59
Resistor, fixed, compcsitien, 5600 ohm ?10%, 1/2 w.
735730-71
502256
7R60
Resistor, fixed, composition, 4700 ohm -?10%, V2 w. Same as 7R3 ..
735730-70
502247
7R61
Resistor, fixed, composit:on, 5600 omh -.L-10%, 1/2 w. *Same as 71(59 ? ?
735730-71
502256
71(62, 7R63
Resistor, fixed, composition, 68,000 ohm ??10.76, 1/2 w. Same as 7R57..
735730-84
502368
7R64
Resistor, fixed, composition, 2200 ohm :1.:10%, 1/2 w. Same as 71(2 ...
735730-66
502222
7R65
Resistor, fixed, composition, 150 ohm -?-10%, 1/2 V.
82283-52
502115
71(66, 71(67
Resistor, fixed, composition, 1000 ohm ?10%, 1/2 w. Same as 711.5 ...
735730-62
502210
7R68
Resistor, fixed, composition, 1800 ohm ?-10%, 1/2 w. (for MI-31496-A
only)
735730-65
502218
71169
Resistor, fixed, composition, 10,000 ohm,.?-10%, 1/2 w. (for MI-31496-A
only)
735730-74
502310
7S1, 7S2
Switch, push, leaf type, form "C" break-make contacts
458953-1
95386
7S3
Switch, push, leaf type, 4 make contacts
458953-2
95387
7S4
Switch, push, leaf type, form "C" break-snake contacts. Same as 7S1
458953-1
95386
7S5
Switch, lever, telephone type, one way locking dpst normally closed
8833320-1
95388
7T1
Transformer, bell ringing
458947-1
95371
7T2
Transformer, filament
949385-1
94196
7XV1 to 7XV4
Socket, tube, 9 pin miniature
984055-2
56333
7XV5, 7XV6
Socket, tube, 7 pin miniature
99370-2
94879
Knob, round black bakelite, for 7R21
712336-507
30075
Screw, thumb, brass, back cover holding
8886111-2
94391
Shield, tube, 7 pin, miniature, 13/4" lg.
99369-2
54521
Shield, tube, 7 pin, miniature, 21/4" lg.
99369-3
57540
Shield, tube, 9 pin, miniature, 11Mo" lg.
-
8858642-3
56359
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
6
7R1
2000
INPUT
CONTROL
7
39K
7FLI
7 R64
2200
7 R2
2200
05C.
6 AH
7R5
47o
7
47R58
"--< 00
7.11
INPUT
60
CALLING AMPL.
12 A K7
7 WO
7R7
2701( 7c5
I(
0.114F.
7CI 7c2
X X
560 560
7R67 7R
1000 I
E 17C5
560 7R10
51" 7R4 IM
1500-1-
7 560 4
7R5 R6
7L1
035 MH.
FAULT AMPL.
12AX7
7R15
4700
7 R60
4700
I MEG
FAULT GATE
CALLING GATE
12.AT7
7 X/V5
7c.7 7C.3 71(2
.0091 0.47W T
MF
7 R6 I
56Oct 7 Ri6
1500
4
5
7 7x/v28
MIME
7 R 17
1VAEG.
7R65
2
HANDSET AMPL.
12 AT 7
HANDSET
VOLUME
7 R21
oac
7 R2
4700
4
7R18
680
IRI41S
56K
7R 20
S Vv
56 vs.
? - -
7 X/V4 A
?R23
270
HANDSET
7J2
7T COMMON
1
LIGHT
RELEASE
752
L--0 0
_ _ L
? 1
1 7 K4
/
X ? C-)
7R54
I8K
LIGHT TEST-1,- --1
753A_
?o o---
7 57
68K
7R62
68 K
7 63
A
-11
-E110
1
_a_
7R53 68K
I8K
REG.
OB2
7 X/V6
?1
A
0
C-TS-9, TS-10
SEE DV/G.0-744085.
-_-_-_-_-__
717
711
?719
0713
/10
? 714
5
L _
711
A
REG.
7C17?
= .01 mF
MIKE ANfPL.
7R21
10K 10K
GA
7X
7C 10
`0.11,48low
I so
7 7
1
i000
K -
7C12
1000
7c18
CALLING 0.1MF
X 17C I4
1000 OUTPUT )1
7crS .__<
1000 7J8 7 FL2.
7R31
270K OUTPUT
05C. 7R34 0 0?
47K
7R32
T T
20oK
7FCS,
UK
SEE NOTE -..,8
Re.61%7
c7R29, < ,Rac,
yQ 270 K
? *
NOTE"!
FOR USE 7R38.0L-IIF 71R4.8 4 7RG9.
FOR 10.-5 CwitT 7R38, AI3O 7R69 7RG9
SHOWN,
RECiPINI
7J3
F-01
4o?
. 5 69
I
TRANS.
7,14-
-ji
--0 31 4C
7R39
39K
7R36
0'4B 50K
;r
?\
11 I
7C16 7R37
IOMF. 220
7R35
300K
MIKE
OUTPUT
?--7-4- 8
Lt. 0
A
;o
r-
7K3
8 r-
7E1 /
o
711.3.
/6
T1
BUZZER RELEASE
Zs 411_
-Co
B. RPLUG TERM. PWRPLv6
7J5 7J6 7J7
?12 11 11 20 lie II 2.50V
14 31-- --D3 4U-1 14 *-
1651 5 6D? i11' 51.
7 BI
IN/1
His LINE P-2 ONLY
ico
75 5 TERMINAL m t
FAULTS 1
0--r9
I 7K5(- 1
1
....- I
I
?fily7 K6
7R36
OK
r-
, , CAPACITOR VALUES GIVEN IN NAME AND ALL
RWEISSEIST5OpRaVcAIFLUIEEDS. GIVEN IN OHMS UNLESS OTNER-
SEE NOTE "I.
F.:vE,EASc, e' Rci.9,7)V.. 13EETT--1 :e*-LN 7CitIRC.I.j[ N T BETWEE : FEI(N
P2 OEJ
( 3 P-I EA.:EPT SEE NCE-1.
FL3 LtEZ, ON ^-^.-'1,196-A
Figure TS-5?Terminal Service Unit, MI-31496?Schematic Diagram
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
694
6021
20/
?
7/-7175.1
170- 75%7-4
/57-7174-1
I
30,5 "?CUP?--70-7X2-
/9-72/5-7
-66 -753-J-00 E.:(/-75 0 -7
/460-7127,17-?
.-/25-753-7
,4
'Oa
4 k
4
r
-
a.
L.
7/-752-2
62 755-2
70 77254
--7
\
.47-771-/
?- /0 - 70C/-5
(11
. ?
k?".
,
4 ,
"
Z......4 769 ' ......1 i t.L- 7210--
.75 '
.11
i I
475- 717135-1 -,
I. 21/ ,gitiri 1.1
90 772 7
52-7712
e-//s..7rer-111
/2 7A-/-/
yre.t
/7 7//5
J- 72 /-55"
-7rAe-es
7787-24-,
//dr 7/21,10
1`-/7.2am,
io.?-772?. 45
?.1
abrAtn
Approved F
49A002600030004-6
47'7N .
0.1",?"'11.-%
nziRi
!yis.,Y4;51
z?It'' 5 -1:
t
.*
i
P
I,-
-R1-0,1GRN
war-eon
1,41/41-000RRER w,R0- 032 DIA
,NNED COPRCR WIRE 010 0/A
..
^
,
.0,
n
r,
k
,
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44
i
4
RPv-atR 15313
?WRE-
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1
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INA
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ilE,Iii
Irrni
, 1,1,..1t.
l'
,...
' ...
Z.' I -S.L
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
MICROWAVE COMMUNICATION EQUIPMENT
T.O. 31R5-4-A-21
Power. Supply MI-31494-B
? TECHNICAL DATA
? DESCRIPTION
* MAINTENANCE
? REPLACEMENT PARTS
RADIO CORPORATION OF AMERICA
COMMUNICATION PRODUCTS. DEPARTMENT, CAMDEN, NEW JERSEY
PRINTED IN U.S.A.
DU 539
11.33230.2
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
-ApprOVid-Fol; Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
\J)PS.1
TECHNICAL DATA
Power Inputs
95 to 125 volts rine 50/60 cycles, 1000 watts
Power Output':
500 volts Ile at full load of 600 ma
ripple: 1.0 volts rms max.
250 volts dc at full load of 500 ma
ripple: 0.030 volts rms max.
115 v ac 50/60 cycles 300w Local Supply Voltage' '
115 v ac 50/60 cycles ?596, 250 W, controlled by auto.
transformer taps.
Weight and Dimensions:
Weight: 275 lbs. packed
225 lbs. net
Height: 14"
Depth Back of Panel:
Depth Front of Panel:
12"
Width: Standard 19" Rack Mounting
Tube Complement
Symbol Type
5V1 3B28
5V2 3B28
5V3 31328
5V4 3B28
Fuses:
Symbol Rating
?
.2 amp.
.2 amp.
.3 amp.
.8 amp.
.8 amp.
5F6
5F7
5F8
5F9
5F10
5F11
5F12
5F13
5F14
5F15
5F16
5F17
5F18
*Refer to the Replacement Part List.
Function
H.V. Rectifier
H.V. Rectifier
L.V. Rectifier
L.V. Rectifier
Circuit
ac common
ac for 250 V. supply
ac for 500 v supply
250 v dc
ac regulated
250 v dc.
500 v dc
ac regulated
ac unregulated
250 v dc.
500 v dc
ac regulated
ac unregulated
DESCRIPTION
The Power Supply MI-31494-B is built for instal-
lation in either a standard 19" open rack or cabinet
and is used in both terminal and repeater stations.
It operates from a 115 v ac, 50-60 cycle source and
supplies 250 v and 500 v dc and 115 v ac to the
other rack units.
Power Supply MI-31494-B has two separate recti-
fying sections each employing two 3B28 rectifier
tubes in a full wave rectifier circuit. Separate high
voltage transformers, 5T3 and 5T2, are provided
for each rectifier section. Rectifier filament voltage
is supplied by a third transformer 5T1, the primary
of which is tapped to permit adjustment of the
regulated ac to 115 volts for several different line
voltages. These primary taps also permit adjustment
of the voltage supplied to the primary of each high
voltage transformer, so that each rectifier output
voltage can be adjusted to near its nominal value for
various values of line voltage and load current.
Each section employs double choke filtering as-
suring a dc voltage with extremely low ripple
content. The ac input circuit and all the ac and
dc output circuits are protected by fuses.
Time delay relay 5K3 is provided to prevent ap-
plication of plate voltage to the rectifier tubes be-
fore the filaments are emitting properly. The
rectifier tubes may be damaged and the' fuses blown
if the filaments are not warmed up before the high
voltage is applied. When line switch 5S1 is closed,
relay 5K3 operates after a time delay of from 20
to 40 seconds. This allows sufficient time for the
filaments to warm up before high voltage is applied
to the plates.
5K3 will not release until from 2 to 3 seconds
has elapsed after opening line switch 5S1. This
prevents sharp drops in line voltage from releas-
ing 5K3 which would cause 20 to 40 second periods
during which the station is not operating.
The voltages available for the other rack units
are 250 and 500 volts dc and 115 volts ac. Plug 5P1
provides the means for making the input connection
to the primary tap of filament transformer 5T1
which best accommodates the actual ac input
voltage. This will also adjust the 115 v ac at termi-
nals 5 and 6 of jacks 5J2, 5J3 and 5J4. 5TB1 pro-
vides a means of changing the ac input to the
+250 v and +500 v rectifying sections. This
permits these supplies to be adjusted to deliver near
their nominal output voltages for different values
of output current.
If the line voltage is not subject to rapid
transients, and if its variation is not greater than
?5% from nominal, this supply can be connected
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
--A) PS-2
Approved For Release Z/0/43111R53444179T01049A002600030004-6
5V2 STK *33286 5 3 504 5M1
5V1
1352
5 X2
681
5X1
5X6
Sc'
5C2
5X7
KX8
508 5013 STK *332813
3TK * 23216
STK *95380 895381
(PART OF 5 X 5)
5 X 10
5 XI3
5 X12
5 X14
5X 17
5 X18
5X16
5V3
5 V4
5X3
5X9
8 XII
8X4
SKIS
5J5
BJ2
5J3
5.11
SPI
5,14
70410
Figure PS-I?Power Supply,
directly to the line. If these conditions are not
adhered to, however, an ac regulating transformer
should be used between the line and the power
supply input.
CONTROLS
a. The LINE switch 5S1 is a double pole single
throw switch which connects and disconnects all
input power.
MI-31494-8?Front View
b. The TRANS TUNE switch 5S2 closes and
opens the 115 vac supply to the primary of trans-
former 5T3 of the 500 volt rectifier section.
c. Lamp 511 illuminates the red jewel on the
fuse panel indicating that the power supply unit is
receiving 115 v ac from its power source, and that
line switch 5S1 is "ON."
d. Hour meter 5M1 registers the total time that
the unit has been in operation.
MAINTENANCE
more than 0.030 volt for the 250 v dc supply the
condition of the filter capacitors 5C1 thru 5C6
should be checked and the faulty capacitor or
capacitors replaced.
c. Check the rectifier filament voltages to see
that they are approximately 2.5 volts.
d. The recommended fuse type for 5F6, 7 and 8
is the Bussman Fusetron Type FNM and for 5F9
thru 5F18 is either Sussman Fusetron Type MDM
or LittleFuk 4AG Slo-Blo.
General Notes
a, Measure the voltage at terminal 5-6 of jacks
5J2, 5J3 or 5J4 periodically to see that the correct
connection in plug 5P1 is being used. Also check
the dc output voltages to see that the proper con-
nections to 5TB1 are beats used.
b. If an objectional 120 cycle hum develops in
the equipment, check the ripple voltage in both
the 500 v and 250 v dc outputs. If the ripple voltage
is greater than 1 volt for the 500 v dc supply or
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
Typical Power Supply Voltage and Current
Readings
The following are dc voltages measured between
the listed points and ground, The input line
voltage for these measurements is 115 v, and the
jumper in 5P1 is connected from Pin 6 to Pin 1.
For the full load condition the 5T2 input is con-
nected to the 115 v tap, on terminal board 5TB1.
For the minimum load condition the 5T2 input is
connected to the 105 v tap on 5TB1. 5T3 input
is connected through switch 5S2 to the 115 volt
tap on 5TB1 under other load conditions.
D. C. Voltages
Point
Full Load
Voltage
'
Min. Load Voltage
Pin 4, 5V1-5V2
564
564
High Side, 5C1 .
533
557
Pin 2, 5J4
500
550
Pin 2, 5J3
, 500
550
Pia 4, 5V3, 5V4
300
283
High Side, 5C3
275
270
Pin 1, 5J4
250
250
with proper 5Th1
connections
Pin 1, 5J3
250
250
with proper 5TB1
connections
PS-3
The following are the rms ac voltages and cur-
rents measured between various points in the power
supply. These readings were taken with the same
?
conditions exisiting as described for the dc voltage
measurements.
A.C. R.M.S. Voltages
Voltmeter .
Position
Full Load
Voltage
Min. Load Voltage
Across primary 5T3 ...
115
115
Plate 5V1 to ground ...
645
650
Plate 5V2 to ground ...
645
650
Across primary 5T2 ...
115
115
Plate 5V3 to ground ...
370
330
Plate 5V4 to ground ...
370
330
Pin 3 to Pin 5, 5J1 ...
95
95
Pin 4 to Pin 5, 5J1 ..
105
105
Pin 1 to Pin 5, 5J1 ...
115
115
Pin 2 to Pin 5, 5J1 . . .
125
125
Pin 5 to Pin 6, 5J2-3-4 .
115
115
Pin 5 to Pin 4, 5J3-4 ..
115
115 '
A.C. R.M.S. Currents
Ammeter
Position
Full Load
Current
.
Min. Load Current
Across Fuse Holder 5X8
(5F8 removed)
Across Fuse Holder 5X7
( 5F7 removed)
Across Fuse Holder 5X6
( 5F6 removed)
3.7 amps.
1.8 amps.
8.2 amps.
1.1 amps.
.92 amps.
?
REPLACEMENT PARTS LIST
Symbol No.
Description
Drawing No.
Stock No.
,5C1-,--5C2---
- Capacitor, fixed, paper, 10 mf., -?-20%, 1000 v.
984619-117
18118
5C3 to 5C6
Capacitor, fixed, paper, 10 mf., -I:20%, 600 v.
984619-108
18501
5F1 to 5F5 ,
5F6
Not used.
Fuse, cartridge, 8 amp., 250 v. (for use at all non-standby terminal or
repeater stations and junction terminal or repeater stations, not utilizing
baseband bridge M1-3n51)
8835339-3
95105
5F6
Fuse, cartridge, 10 amp., 250 v. (for use at all standby stations and non-
standby junction stations utilizing the baseband bridge MI-31150`
8835339-6
96162
5F7
Fuse, cartridge, 2 amp., 250 v. (for terminal or repeater station only)
8835339-1
95107
5F7
Fuse, cartridge 2.5 amp., 250 v. (for terminal or repeater station with
standby only)a
8835339-4
96160
5F8
Fuse, cartridge, 4 amp., 250 v. (for terminal or repeater station only)
8835339-2
95106
5178
Fuse, cartridge, 5 amp., 250 v. (for terminal or repeater station with standby
only)
8835339-5
96161
5F9
Fuse, cartridge, 0.2 amp., 250 v. (for terminal or repeater station only) .
8835338-2
95109
5F10
Fuse, cartridge, 0.5 amp., 250 v. (for terminal stations with terminal service
unit, junction terminal or repeater stations with filter gind relay panels,
or service channel bridge)
8835338-8
56069
,
?
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6 ?
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
PS-4
App
?
T.O. 311R5-4-A-21
Symbol No.
Description
,
Drawing No.
Stock No.
5F10
Fuse' cartridge, 1.25 amp., 125 v. (for terminal stations svith service channel
unit and indicon decoder, repeater stations vvith service channel unit
?
and indicon coder or decoder)
8835338-12
215880
5F10
Fuse, cartridge, 0.8 amp., 250 v. (for repeater station with repeater service
unit)
8835338-4
95111
5F10
Fuse, cartridge, 2.5 amp., 125 v. (for junction terminal or repeater stations
with baseband bridge MI-31151 and relay panel or service channel
bridge)
8835338-11
97440
5F11
Fuse, cartridge, 0.2 amp., 250 v. ((or terminal or repeater station only)
Same as 5F9
8835338-2
95109
5F12 ,
Fuse, cartridge, 0.3 amp., 250 v. (for terminal or repeater station only)
8835338-3
'95110
5F13, 5F14
Fuse, cartridge, 0.8 amp., 250 v. (for terminal or repeater station only)
8835338-4
95111
5F15
Fuse, cartridge, 0.2 amp., 250 v. (for terminal or repeater station only)
Same as 5F9
8835338-2
95109
5F15
Fuse, cartridge, 0.8 amp., 250 v. (for terminal or repeater station with
standby only) Same as 5F13
8835338-4
95111
5F16
Fuse, cartridge, 0.3 amp., 250 v. (for repeater station only) Same as 5F12
8835338-3
95110
5F16
Fuse, cartridge, 0.8 amp., 250 v. (for repeater station with standby only)
Same as 5F13
8835338-4
95111
5F17 .
Fuse, cartridge, 0.3 amp., 250 v. (for terminal station only) Same as 5F12
8835338-3
95110
5F17
Fuse, cartridge, 0.8 amp., 250 v. (for repeater station only) Same as 5F13
8835338-4
95111
5F17
Fuse, cartridge, 2.5 amp., 125 v. (for terminal or repeater station with
standby only) ,
883533841
97446
5F18
..
Fuse, cartridge, 0.8 amp., 250 v. (for repeater station only) Same as 5F13
8835338-4
95111
5F18
Fuse, cartridge, 2.0 amp., 125 v. (for terminal or repeater station with
standby only)
8835338-5
95557
511
Lamp, pilot light, 120 v., 0.05 amps., 6w. clear candlelabra screw base
61114-9
23216
5J1 to 5J4
Connector, female, 6 contact, chassis mtg. .?
181494-4
18534
5J5
Connector, male, 6 contact, chassis mtg.
181494-3
28507
5K3
Relay, ac, time delay, coil 115 v., 50/60 cy., 3.5 to 5 watts
4708774
204348
5L1, 5L2
Reactor, iron core, 5 henry
949378-1
95372
5L3, 5L4
Reactor, iron core, 10 henry _
949379-1
95373
5M1
Meter, elapsed time, 0-99,999 hours
88333174
95389
5P1
Connector, male, 6 contact, cable mtg.
181494-2
28454
5R1
Resistor, fixed, wire wound, 500 ohms, ?-5%, 10 w.
8817663-14
96267
5R2
Resistor, variable, wire wound, 500 ohms, ?10%, 25 w
108406-5
95374
5R3
Resistor, fixed, wire wound, 50,000 ohms, ?10%, 100w.
449695-18
98116
5R4
Resistor, fixed, wire wound, 25,000 ohms, ?10%, 50 w
182120-12
98117
5S1, 5S2
Switch, toggle, DPST, 15 amps., 125 v., 10 amps., 250 v
449663-109
56882
5T1
Transformer, filament
9493754
95376
5T2
Transformer, plate, pri. 115/124 v., sec. 355-0-355 v.
949376-1 .
95377
5T3
Transformer, plate, pri. 124 v., sec. 645-0-645 v
949377-1
95378
5X1 to 5X4
Socket, tube, for UX-4 pin tubes, with underwriters shield, brkt. type and
upright panel mtg. (special) i
8843563.1
93654
5X5
Pilot light assy. (red )
458948-1
5X6 to 5X8
Holder, fuse, panel mtg., for 11/2" lg. x 1302" dia. fuse
88718274
95379
5X9 to 5X18
Fuse, holder, cartridge, panel mtg. for 11/4" x 9/32" dia. fuses
99088-1
58933
Socket, pilot light socket only less lamp and jewel (pt. of 5X5)
4589484
95380
Jewel, pilot light red jewel only, less socket and lamp (pt. of 5X5)
458948-1
95381
0
Miscellaneous '
Connector, tube cap, with 36" cable
896952-502
33288
Approved For Release 2001/03+46Clehlitqa0.1449A002600030004-6
? .?????
PS-5
Figure PS-2?Power Supply, Ml-31494-8?Reor View, Dust Cover Removed
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
SP)
STB 1 0
14
S52
sfc ,5
.06)0
1
3828
573
3828
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Figure P5-3?Power Supply, MI-31494-B----Schematic Diagram
a
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
5LZ
a
11
I I
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SP
T.O. 31R5-4-A-21
Lir
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Figure PS-4?Power Supply, MI-31494-B--Connection Diagram
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
MICROWAVE COMMUNICATION EQUIPMENT
T.O. 31R5-4.A-21
Terminal AFC Unit MI-31492C
? TECHNICAL DATA
? DESCRIPTION
? MAINTENANCE
? REPLACEMENT PARTS
RADIO CORPORATION OF AMERICA
COMMUNICATION PRODUCTS DEPARTMENT, CAMDEN, NEW JERSEY
PRINTED u5p rN o v
D u s4
. .
edFor Release 2001/03/04: CIA-RDP79T01049A00260003000U228-2
D
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
gAFC-i
TECHNICAL DATA
Power Input
a. Filament Heaters: 19 watts at 115 v, 50/60
cycles ac
b. Plate Supply: 95 milliamps at 250 v dc
Crystals
Symbol Type
3CR I 1N21B
3Y1 MI-31687?*
(See Note)
Function
AFC Mixer
Beating Oscillator
I-F Frequency
20 mc
Tube Complement
?
Bandwidth
Symbol
Type
Function
2 mc
3V1
6CB6
First i-f Amplifier
3V2
6CB6
Second i-f Amplifier
3V3
6CB6
Third i-f Amplifier
Required IR-F Input
1 mw
3V4
3V5
6C136
GALS
Fourth i-f Amplifier
Discriminator
3V6
12AT7
Oscillator/Multiplier
110 MC Output
3V7
6U8
55 MC Amplifier and
Multiplier
2 volt
3V8
6CB6
55 MC Oscillator
3V9
6AH6
Reactance Control
Weight and Dimensions
Weight--7 lbs.
Height-51A,,
Depth Back of Panel: 27/8"/
Depth Front of Panel: 21/2"
Width-19" Rack Mounting
NOTE: The letter-number suffix (*) of the
MI-31687 crystal series is determined by the sys-
tem frequency assignment. Consult the system
instructions for Typical System Frequencies.
DESCRIPTION
The Terminal AFC Unit (MI-31492-C) is designed ?
for mounting in either a standard 19" open rack or
cabinet. It is mounted adjacent to the transmitter
unit and is used in terminal stations only. This unit
keeps the terminal transmitter stabilized at its as-
signed frequency. This is extremely important because
the frequency of the whole relay chain is controlled
by the terminal station transmitter frequency.
The transmitter frequency is compared with a
reference frequency from a quartz crystal controlled
oscillator. The error voltage is used to change the
frequency of a 55 mc oscillator, the frequency of
which is doubled in the multiplier stage. The mul-
tiplier output changes the receiver/modulator 1-F
mixer frequency which corrects the transmitter
carrier frequency.
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Releaa03titill440/11RDP79To1049A002600030004-6
AFC-2
I. The basic control frequency of the Terminal
AFC Unit M1-31492-C is generated by the crystal con-
trolled oscillator/multiplier 3V6. The frequency of
the quartz crystal 3Y1 of the crystal oscillator 3V6
is calculated from the following equation:
F F
Fc ? '
2X
where: F,. is the frequency of the quartz crystal
3Y1 of the crystal oscillator
F, is the transmitted frequency
Fr is the received frequency
X is the multiple of the crystal frequency
and is found in the following table:
F, F,
Range
Value of X
of
2
1720 MC to 1840 111C
44
1841 mc to 2000 mc
48
2001 mc to 2160 mc
52
2161 MC to 2320 mc
56
2321 mc to 2470 MC
60
2471 mc to 2640 111C
64
2641 mc to 2680 mc
68
Refer to the systems book for Typical System
Frequencies.
2. The oscillator/multiplier 3V6 generates the
heteroOning frequency required in the 3Z1 mixer
cavity. The plate circuit of the oscillator section
of 3V6 is tuned to the frequency of the crystal (3Y1).
The plate circuit of the multiplier section of 3V6 is
tuned to the 4th harmonic of the crystal. The output
of this stage is fed to the 1N21B crystal in the resonant
mixer cavity 3Z1. The other mixer frequency is
a sample of the microwave transmitter output
which is fed by coaxial cable to the R.F. CARRIER
INPUT terminal 3J1 of mixer cavity 3Z1. The trans-
mitter frequency is heterodyned with a high order har-
monic of the crystal multiplier to produce a differ-
ence frequency of 20 mc. The actual harmonic used
may be from the 11th to the 17th depending on the
3V9 3J3 3V5 3V4 3J9 3V3 3V2
3VI 3J2 3Z1 31I
3V8 3V7 3J7 3J8 3YI
Figure AFC-1?Terminal AFC Unit, MI-31492-8 and MI-37492-C----Front View
Approved For Release 2001103104: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
frequency of the transmitter. The harmonic used
is found by dividing the value of X in the equa-
tion, by four. The adjustable screw in the cavity
tunes it to the frequency of the signal from the
transmitter and the adjustable loop inside terminal
3J1 controls the amount of the signal input.
With the transmitter operating on its specified
frequency the i-f output of 3Z1 is 20 mc. The
mixer output is amplified through four i-f stages
and then applied to discriminator 3V5 which is
tuned to 20 mc. A 20 mc signal will cause a 0
discriminator output. Any variation of the trans-
mitter frequency will change the frequency of the
i-f input to 3V5 with a resultant dc discriminator
output voltage. The dc voltage from 3V5 is applied
to the reactance circuit of 3V9 which changes the
frequency of the 55 mc oscillator (3V8) relative
to the amount of dc applied to 3V9 from the dis-
criminator. The 55 mc output of 3V8 is doubled
in the amplifier/multiplier stage 3V7. A change
in the 110 mc output of 3V7 occurs only if the trans-
mitter output frequency tends to drift. The 110
mc output of 3V7 is fed to mixer 2V10 in the
receiver/modulator unit.
In the receiver/modulator unit the 110 mc out-
put of the AFC unit heterodynes with the 40 mc
f-m signal in mixer stage 2V10 to produce the 70
mc subcarrier which modulates the microwave
carrier. Any variation in the 110 mc output fre-
quency of the AFC unit will cause 2V10 to either
increase or decrease the frequency of the 70 mc
signal carrier. Any fluctuation (increase or de-
crease) in the transmitter local oscillator (1V2)
frequency will be compensated for in the trans-
mitter mixer stage (1V3) by a corresponding
decrease or increase in the 70 mc carrier frequency,
thereby correcting the transmitted microwave car-
rier frequency. (Refer to the terminal station block
diagram of the system book for the automatic fre-
quency control circuit.)
CONTROLS
fl")
EAFC-3
6-7-8 section of 3V6) to the 4th harmonic of the
crystal oscillator.
d. The MIXER XTAL pin jack 3J2 is used to
connect meter 1M1 to indicate when the multiplier
stage (6-7-8 of 3V6) is tuned to the 4th harmonic
of the crystal oscillator.
e. The crystal mixer cavity R.F. CARRIER IN-
PUT terminal 3J1 is the receptacle for connecting
the cable which supplies a sample of the output
frequency from the transmitter.
a?TheXTAtOSC tuning screw is for adjusting
the plate peaking coil 3L22 of the crystal oscillator
(the 1-2-3 section of 3V6) to the crystal frequency.
b. The OSC GRID pin jack 3J4 is used to con-
nect meter 1M1 to indicate when the crystal oscil-
lator (1-2-3 of 3V6) is tuned (by the XTAL OSC
screw) to the frequency of the crystal 3V1.
c. The MULT tuning screws of coils 3L21 and
3L17 are for adjusting the multiplier stage (the
Approved For Release 2001/03/04: CIA
f. The tuning screw of the crystal mixer cavity is
for resonating the cavity to the frequency of the
transmitter.
g.
The LIMITER pin jack 3J9 is for connecting
meter 1M1 to show when the crystal mixer cavity is
tuned to resonance at the transmitter frequency.
h. The DISC pin jack 3J3 is used to connect
meter 1M1 when checking the discriminator dc
voltage output when tuning the AFC and trans-
mitter.
i. The 55 MC OSC tuning screw of coil 3L24 is
for adjusting the frequency of the 55 mc oscillator
3V8.
j. The 55 MC OSC GRID pin jack 3J7 is used to
connect meter 1M1 to check the grid current when
adjusting 3V8 to 55 mc with the 55 MC OSC tuning
screw.
k. The 55 MC AMP tuning screw of coil 3L23 is
for adjusting the frequency of the 55 mc amplifier
stage ( the pentode section, elements 7-2-3-6, of
3V7).
1. The MULT 3T3 tuning screw of transformer
3T3 is for adjusting the frequency of the 110 mc
amplifier stage ( the triode section, elements 8-9-1,
of 3V7).
m. The 110 MC OUTPUT jack 3J8 is used to
connect the output of the 110 mc multiplier stage
(3V7-8-9-1) to the 110 MC INPUT jack of the
receiver.
-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
AFC-4
MAINTENANCE
General Notes
a. To check the operation of the AFC unit
connect the test meter, IMI, test lead to the "DISC"
jack. 1M1 should read zero. When the transmitter
oscillator cavity is squeezed, the 1M1 reading
should increase to approximately 50 pa if the AFC
unit is working properly.
b. If the transmitter r-f output fails completely
one of the possible causes could be the failure of
the terminal AFC unit to deliver a 110 mc signal
to the modulator i-f mixer of the receiver/modula-
tor. There is no 70 mc drive to the transmitter
during the absence of the 110 mc frequency from
the terminal AFC unit.
c. If the terminal AFC unit is the cause of the
transmitter failure, check the tubes and replace the
ones that are bad. The four i-f tubes and discrimi-
nator tube (3V1 thru 3V5) can be changed without
retuning any of the circuits. If the oscillator/multi-
plier tube 3V6 is changed, tuning coils 3L21, 3L22,
3L17, 3L16, 3L15 and 3C39 should be repeaked as
follows:
1. Connect the transmitter test meter 1M1 to
the OSC GRID 3J4 and tune the XTAL OSC con-
trol 3L22 for maximum grid current. A reading
of at least 70 iLa should be obtained.
2. Connect meter 1M1 to the MIXER XTAL
jack 3J2 and tune the MULT controls 3L21 and
3L17 for maximum current. Since this is a double
tuned circuit it is advisable to keep the cores at
about the same depth, when tuning over any great
range, in order to get an initial reading to
maximize. The meter reading should be 25 pa or
more. (To obtain a peak indication when tuning
this circuit it may be necessary to remove the r-f
cable connecting the transmitter output to the crys-
tal cavity on the terminal AFC unit. The cable
should be replaced immediately after peaking the
circuit.)
d. If either the 55 mc oscillator, 110 mc multi-
plier or reactance tube (3V8, 3V7, 3V9) is changed,
the tuned circuits of these stages should be retuned
as described in the CIRCUIT ALIGNMENT section,
and the operation of the AFC system checked as
follows:
Check the terminal AFC unit discriminator read-
ing by connecting the test meter INC to the jack
marked "DISCR". If the meter reading is not zero,
adjust the 55 MC OSC control 3L24 very slowly
until the meter reads zero. The transmitter AFC
motor may run when the 55 mc oscillator frequency
is changed slightly. After a slight change in the fre-
quency of the 55 mc oscillator is made, wait for the
AFC tuning motor indicator light to go out before
continuing adjustment. Keep adjusting 3L24 in this
manner until the DISC reading is zero. If this ad-
justment is considerably off the correct point, a zero
discriminator current will also be observed, but in
this case of improper adjustment, there will be a
very small reading of limiter current on this unit
instead of the normal value of 25 p.a or more. After
the zero reading is reached tune the 55 MC AMP and
MULT 3T3 controls for maximum output at 3J8
as described in item (b) of the 55 MC Oscil-
lator/Multiplier Circuit test in the following CIR-
CUIT ALIGNMENT section.
CIRCUIT ALIGNMENT
The following headings contain detailed align-
ment and test procedure for all the circuits of the
terminal AFC unit. These tests and alignments
should be made with the unit on a test bench. The
test items specified in the following procedures re-
fer to the test equipment items listed in the test
equipment tables of the system instructions. Use test
item 19 to supply power to operate the terminal
AFC unit.
Crystal Oscillator Circuit Test
Connect the microammeter to 3J4 (OSC GRID)
and adjust the XTAL OSC control 3L22 for maxi-
mum grid current as indicated on the meter. A cur-
rent reading of 80 ixa or more indicates satisfactory
operation.
Multiplier Circuit Tuning Adjustment
Connect the microammeter to 3J2 (MIXER
CRYSTAL) and tune the MULT controls 3L21.
and 3L17 for maximum current. A reading of 50 I.La
is adequate. Be sure the current can be maximized
by tuning either coil.
55 Mc Oscillator/Multiplier Circuit Test
a. Connect the microammeter to 3J7. Ground
the junction of 3R35 and 3R37. With the core of
3L25 in the mid-position adjust the 55 MC OSC
Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
Approved For Release 2001/130 :ifitgX1M1049A002600030004-6
3T1 3R39 3CRI 3C3 3R3 3R30
3R4 3C35 3L201 3.12 3VX1
FAFC-5
3R7 3L3 5R11 3VX3 3J9 3R38 3R15 3VX4 3L6
3 L 2 3VX 2 31.13 3C9 3C11 3I4 3 R 41 3C36 3C15 3V X5
? 3,15 3L17 3C42 3R I 5 3C69
3L26 3 21 3L12 3.14 311 2 3 X6 3-6
8 3 8 3-12 3C12 3,18 3 6 8
3L22 R9 3CI0 311I3 3C14 3-18 3X V7 3C58 3 23
77449
Figure AFC-2?Terminal AFC Unit, M1-31492-C?Rear View, Dust Cover Removed
control 3L24 for a frequency of 55 mc. (Use test
item 13). Adjust 3L25 for a reading of 55 ?a. Re-
adjust the frequency, if necessary, to 55 mc zt0.1
mc.
b. Connect the r-f voltmeter (test item 22) to the
110 MC OUTPUT jack 3J8 and adjust the 55 MC
AMP Control 3L23 and the MULT 3T3 control for
maximum output. A reading of at least 2 volts must
be obtained.
Discriminator and I-F Alignment
a. Connect the CRO to 3V5-5.
b. Connect the 20 mc sweep generator (test item
18) output to 3V4-1.
c. Adjust 3L5, 3L6, and 3L8 for the correct dis-
criminator response. No great amount of time
should be spent in obtaining exact linearity. It is
essential that the alignment be such that the dis-
criminator peaks are 3 mc apart and that cross-
over is located at 20 mc. Remove the sweep gen-
erator and oscilloscope.
d. Connect the microammeter to the LIMITER
jack 3J9.
e. Connect the signal generator (test item 16)
to 3V3-1 and set it for exactly 20 mc.
f. Tune 3L4 for a maximum meter reading. Re-
duce the signal generator output for a meter reading
of approximately 50 ?a.
g. Move the signal generator to 3V2-1 and tune
3L3 for a maximum reading at 3J9. Adjust the
signal generator for a meter reading at 3J9 of ap-
proximately 50 "Aa.
3V X9
31,167
31.24
3L25
3.13
3R68
3VX8
31.26
31_5
7
h. Move the signal generator to 3V1-1 and tune
3L2 for a maximum reading at 3J9. Adjust the
signal generator for a meter reading at 3J9 of ap-
proximately 50 0.
i. Connect the Voltohmyst probe to 3V5-1. Use
the most sensitive scale. While maintaining the
signal generator output to produce limiter satura-
tion, tune 3L6, 3L7 and 3L8 so the crossover voltage
is exactly at 20 mc and the two peaks are at 18.5
and 21.5 mc -?0.2 mc and of approximately equal
amplitude. Coil 3L7 controls the amplitude, 3L6
the high frequency peak and 3L8 the low frequency
peak. Remove the signal generator, microammeter
and Voltohmyst.
I.F. Gain Measurement
a. Connect
ITER).
the microammeter to 3J0 (LIM-
b. Remove the 1N21B from its socket.
c. Connect the 20 mc signal generator to the low
end of 3L1.
d. With sufficient output to get a small reading
on the microammeter tune 3L1 for a maximum re-
sponse at 20 mc.
e. It should now require not more than 2000 IA,
to obtain a reading of 1001a at 3J9 (LIMITER).
Reactance Tube Sensitivity Test
a. Connect the Voltohmyst to the DISC jack 3J3
with the signal generator connected as in (c) of the
I-F Gain Measurement test.
b. Tune the signal generator to 20 mc for a zero
reading at 3J3.
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31 R5-4-A-21
AFC-6
c. With the conditions as above, tune the 55 MC
OSC control 3L24 for a 55 mc ?-0.1 mc frequency
reading. Measure the frequency at the 110 MC
OUTPUT jack 3J8 using tOSC it4501 13.
d. Change the frequency of the 20 mc signal gen-
erator until the Voltohmyst reads 1 volt and again
measure the frequency at 3J8. The difference be-
tween this measurement and that at (c) should not
be less than ? 1 mc.
R-F Mixer Circuit Test
a. Replace the 1N21B.
b. Orient the plane of the loop on 3J1 (R-F
CARRIER INPUT) perpendicular to the long axis
of 3Z1.
c. With the unit operating normally, connect
the 2700 mc signal generator (test item 17) to R-F
CARRIER INPUT 3J1.
d. Connect the microammeter to 3J9 (LIM-
ITER).
e. With the signal generator set for approxi-
mately 1 milliwatt output, tuning the signal gen-
erator to the correct frequency should give a re-
sponse in the i-f amplifier as indicated on the
microammeter.
NOTE: There are several frequencies that will
give a response. For a given crystal frequency,
signal generator frequencies at which a re-
sponse will be obtained are equal to the crys-
tal frequency, in megacycles, multiplied by 44,
48, 52, 56, 60, 64 or 68 with 20 mc added or
subtracted from the product.
f. 3Z1 should be tuned for a maximum i-f
response. The reading at 339 must be at least
40 ma.
g. Retune 3L1 for maximum response.
TYPICAL TERMINAL AFC VOLTAGE AND METER READINGS
The following are approximate voltages existing between the indicated tube pins and ground as meas-
ured with a Voltohmyst with 100,000 ohms in series with the measuring probe. All voltages are dc unless
otherwise noted.
Tube
Type
Function
Pin
#1
Pin
#2
Pin
#3
Pin
#4
Pin
#5
Pin
#6
Pin
#7
Pin
#8
Pin
#9
3V1
6CB6
1-F Ampl.
0
2
6.3 ac
0
210
140
0
?
3V2
6CB6,
1-F Ampl. ,
0
2
6.3 ac
0
210
140
0
?
?
3V3
6CB6
I-F Ampl.
0
2
6.3 ac
0
210
140
0
?
?
3V4
6CB6
Limiter
0
1.2
6.3 ac
0
60
80
0
?
?
3V5
6AL5
Detector
0
var*
6.3 ac
0
var*
0
var.*
?
3V6
12A1C7
Crystal Osc./Mult.
180
0
2.7 ac
0
0
220
0
9.6
6.3 ac
3V7
6U8
55 mc Amp./110
mc Mult.
130
0
110
0
6.3 ac
200
1.6
2.5
0
3V8
12AT7
55 mc Osc.
160
0
0
0
0
160
0
0
6.3 ac
3V9
6AH6
React.
var*
3.3
6.3 ac
0
160
140
3.3
?
var*?variable with signal level and frequency.
The following are typical meter readings obtained using the 200 microampere test meter (1M1) in the
transmitter unit.
Mixer Xtal. (3J2) ? ?15 to ?75 tut
Disc. (3.113) ? zero for on-frequency operation; up to off scale plus or minus for off-frequency
operation
Osc. Grid (3J4) ? ?110 pa
55 mc Os. Grid (3J7) ? ?45 pa
Limiter (3J9) ? ?25 pa
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
'FC-7
REPLACEMENT PARTS LIST
TERMINAL AFC UNIT-MI-31492-C
Symbol No,
Description
Drawing No..
_
Stock No.
3C1, 3C2, 3C3
Capacitor, fixed ceramic, 1500 mmf, +100 -0%, 500 v.
449696-3
73748
3C4
Capacitor, fixed ceramic, 220 mmf, -1:20%, 500 v.
735717-133
10 20 15
3C5, 3C6, 3C7
Capacitor, fixed ceramic, 1500 mmf, +100 -0%, 500 v. Same as 3C1
449696-3
73748
3C8
Capacitor, fixed ceramic, 220 mmf, -?-20%, 500 v. Same as 3C4
735717-133
1020 15
3C9, 3C10, 3C11
Capacitor, fixed ceramic, 1500 mmf. +100 -0%, 500 v. Same as 3C1
449696-3
73748
3C12
Capacitor, fixed ceramic, 220 mmf, -?20%, 500 v. Same as 3C4
735717-133
10 20 15
3C13, 3C14
Capacitor, fixed ceramic, 1500 mmf, +100 -0%, 500 v. Same as 3C1
449696-3
73748
3C15
Capacitor, fixed ceramic, 15 mmf, ?20%, 500 v.
735717-119
94195
3C16
Capacitor, fixed ceramic, 4700 mmf, :000 -0%, 500 v.
990119-11
73473
3C17 to 3C27
Not used.
3C28
Capacitor, fixed ceramic, 1500 mmf. +100 -0%, 500 v. Same as 3C1
449696-3
73748
3C29
Not used.
3C30
Capacitor, fixed ceramic, 1500 mmf, +100 -096, 500 v. Same as 3C1
449696-3
73748
3C31, 3C32, 3C33
Not used.
3C34
Capacitor, fixed paper, 0.1 mf, -?10%, 400 v.
735715-175
73551
3C35
Part of 3Z1.
3C36
Capacitor, fixed ceramic, 1500 mmf, +100 -0%, 500 v. Same as 3C1
449696-3
73748
3C37 to 3C41
Not used.
3C42
Capacitor, fixed mica, 8 mmf, -?-5%, 300 v.
748252-308
205068
3C43
Capacitor, fixed mica, 10 mmf, -?-5%, 300 v.
748252-310
59905
3C44 to 3C49
Not used.
3C50
Capacitor, fixed ceramic, 1.5 mmf, -?-0.25 mmf, 500 v.
722401-54
78928
3C51, 3C52, 3C53
Capacitor, fixed ceramic, 820 mmf, +100 -0%, 500 v.
449696-1
94190
3C54
Capacitor, fixed ceramic, 27 mmf, -_1:5%, 500 v.
90575-219
79488
3C55
Capacitor, fixed ceramic, 820 mmf, +100 -0%, 500 v. Same as 3C51
4496964
94190
3C56
Capacitor, fixed ceramic, 8 mmf, -?0.5.mmf, 500 v.
90575-207
99600
3C57
Capacitor, fixed ceramic, 820 mmf, +100 -0%, 500 v. Same as 3C51
449696-1
94190
3C58
Capacitor, fixed ceramic, 100 mmf, -?-20%, 500 v.
735717-129
10 185 3
3C59, 3C60
Capacitor, fixed ceramic, 820 mmf, +100 -0%, 500 v. .Same as 3C51
449696-1
94190
3C61
Capacitor, fixed ceramic, 470 mmf, Li:20%, 500 v.
735717-637
75198
3C62, 3C63
Capacitor, fixed ceramic, 820 mmf, +100 -0%, 500 v. Same as 3C51
449696-1
94190
3C64
Capacitor, fixed ceramic, 100 mmf, -?-20%, 500 v. Same as 3C58
735717-129
10 1853
3C65
Capacitor, fixed ceramic, 820 mmf, +100 -0%, 500 v. Same as 3C51
449696-1
. 94190
3C66
Capacitor, fixed ceramic, 100 mmf, -?-20%, 500 v. Same as 3C58
735717-129
10 1853
3C67
Capacitor, fixed ceramic, 470 mmf, -1:20%, 500 v. Same as 3C61 . .
735717-637
75198
3C68
Capacitor, fixed ceramic, 820 mmf, +100 -0%, 500 v. Same as 3C51
449696-1
94190
3C69
Capacitor, fixed ceramic, 10 mmf, ?0.5 mmf, 500 v.
90575-209
98225
3CR1
Rectifier, germanium diode
1N2113
67876
331
Connector, female, coaxial, coupling loop assembly, chassis mtg. ...
8834436-501
94231
3J2, 333, 334
Connector, female, pin jack
742565-1
93678
3J5
Connector, male, 6 contact, chassis mtg.
181494-3
28507
336
Not used.
317
Connector, female, pin jack. Same as 3J2
742565-1
93678
3J8
Connector, female, coaxial, chassis mtg.
8845666-1
94205
3J9
Connector, female, pin jack. Same as 332
742565-1
93678
...--
-
Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
AFC-8
Symbol No.
Description
Drawing No.
Stock No.
3L1
Coil, adj. iron core
629132-507
94240
3L2, 3L3, 31.4
Coil, adj. iron core
629132-508
94250
3L5
Coil, adj. iron core
629132-501
94251
3L6
Coil, adj. iron core
629132-505
94236
3L7
Reactor, r-f choke, 50 microhenrys
8834437-502
94242
3L8
Coil, adj. iron core. Same as 3L5
629132-501
94251
3L9, 3L10, 3L11
Not used.
3L12
Reactor, r-f choke, 2.4 microhenrys ?
8834424-501
94040
3L13
Reactor, r-f choke, 2.4 microhenrys. Same as 3L12
8834424-501
94040
3L14 to 3L16
.
Not used.
3L17
Coil, adj. core, mult. plate tuning, 160 mc. .
8864102-4
204735
3L18, 3L19
Not used.
3L20
Reactor, r-f choke, 6.8 microhenrys
941524-245
217800
3L21
Coil, adj. core, mult plate tuning, 160 mc. Same as 3L17
48864102-4
204735
31.22
Coil, adj. core, osc. plate tuning, 40 mc.
8864102-2
204736
3L23
Coil, adj. core, 55 mc. plate output tuning
88641014
204737
3L24
Coil, adj. core, osc. plate tuning, 55 mc.
8864102-3
204738
3L25
Coil, adj. core, osc. grid tuning, 55 mc.
629132-517
94245
3L26
Reactor, r-f choke, 6.8 microhenrys. Same as 3L20
941524 245
217800
3L27
Reactor, r-f choke, 2.4 microhenrys. Same as 3L12
8834424-501
94040
3L28 ?
-..,
Reactor, r-f choke, 39 microhenrys
473909-39
205859
3R1, 3R2
Not used.
3R3 ,
Resistor, fixed composition, 180 ohm, -?100/0, 1/2 w.
82283-53
3R4
Resistor, fixed composition, 47,000 ohm, 71..--10%, 1 w.
90496-82
3R5
Resistor, fixed composition, 4700 ohm, -?-10%, 1 w.
9049647
3R6
Resistor, fixed composition, 1500 ohm. -?.1096, 1/2 w.
82283-64
3R7
Resistor, fixed composition, 180 ohm, -1-..10%, 1/2 w. Same as 3R3 ...
82283-53
3R8
Resistor, fixed composition, 47,000 ohm, -?10%, 1 w. Same as 3R4
90496-82
3R9
fixed composition, 4700 ohm, -?-200/0, 1 w. Same as 3R5 2 .
90496-17
3R10 - -- -
_Resistor,
Resistor, fixed composition, 1500 ohm, ?-10%, 1/2 w. Same as 3R6
82283-64
3R11
Resistor, fixed composition, 180 ohm, -?-10%, 1/2 w. Same as 3R3
82283-53
3R12
Resistor, fixed composition, 47,000 ohm, -1:10%, 1 w. Same as 3R4 .
90496-82
3R13
Resistor, fixed composition, 4700 ohm, .-L-20%, 1 w. Same as 3R5
90496-17
3R14
Not used.
3R15
Resistor, fixed composition, 180 ohm, -?-10%, 1/2 w. Same as 3R3 ...
82283-53
3R16
Resistor, fixed composition, 22,000 ohm, -1-20%, 2 w.
99126-21
3R17
Resistor, fixed composition, 4700 ohm, ?10%, 1/2 w.
82283-70
3R18, 3R19
Resistor, fixed composition, 27,000 ohm, 1.-10%, 1/2 w.
.
82283-79
3R20 to 31129
Not used.
3R30
Resistor, fixed composition, 27,000 ohm, ?1096, 1/2 w. Same as 3R18
82283-79
3R31 to 3R34
Not used.
3R35
Resistor, fixed composit:on, 4700 ohm, ?1070, V2 w. Same as 3R17
82283-70
3R36
Not used.
3R37
Resistor, fixed composition, 1 meg. ?,200/0, 1/2 w.
82283-31
3R38
Resistor, fixed composition, 100 ohm, -?.5%, 1/2 w-
82283-135
3R39
Resistor, fixed composition, 3900 ohm, -?-10%, 1/2 w.
82283-69
3R40
Resistor, fixed composition, 33 ohm, -L-10%, 1/2 w. (part of 331 assy) .
82283-44
3R41
Resistor, fixed composition, 3900 ohm,;-_109f2, 1/2 w. Same as 3R39
82283-69
3R42
Resistor, fixed composition, 3300 ohm, ?1096, 1 w.
90496-68
3R43,?
to 3R49
Not used.
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
T.O. 31R5-4-A-21
,e-AFC-9
Symbol No.
Description
Drawing No.
-Stock No.
3R50
Resistor, fixed composition, 10 ohm, ?109fi, 1/2 w.
82283-38
31131
Resistor, fixed composition, 27,000 ohm, -?1004, 1/2 w. Same as 3R18
82283-79
3R52
Resistor, fixed composition, 100 ohm, -1-.10%, 1/2 w.
82283-50
3R53
Resistor. fixed composition, 1000 ohm, ?10%, 1/2 w.
82283-62 '
3R54
Resistor, fixed composition, 270 ohm, -1:10%, 1/2 w.
82283-55
3R55, 3R56
Resistor, fixed composition, 8200 ohm, :OM 2 w.
99126-73
3R57
Resistor, fixed composition, 390 ohm, -?-1004, 1/2 w.
82283-57
3R58
Resistor, fi,ed composition, 180 ohm, ?10%, 1/2 w. Same as 3R3
82283-53
3R59
Resistor, fi d composition, 6800 ohm, ??10%, 1/2 w?
82283-72
3R60
Resistor, fixed composition, 68,000 ohm, ?1096, 1/2 w.
82283-84
3R61
Resistor, fixed composition, 5600 ohm, -.1-1096, 1/2 w.
82283-71
3R62
Resistor, fixed composition, 22,000 ohm, ?.10%, 1/2 w.
82283-78
3R63
Resistor, fixed composition, 1500 ohm, J-1096, 1/2 w. Same as 3R6 .
82283-64
3R64
Resistor, fixecicomposition, 180 ohm, ?10%, 1/2 w. Same as 3R3
82283-53
3R65
Resistor, fixed composition, 1000 ohm, ?1096, 1/2 w. Same as 3R53
82283-62
3R66
Resistor, fixed composition, 4700 ohm, ?109(2, 2 w.
99126-70
3R67
Resistor, fixed composition, 47,000 ohm, ?1096, 1 w. Same as 3R4
90496-82
3R68
Resistor, fixed composition, 100,000 ohm, ?1096, 1/2 w. ...... ,
82283-86
3T1
Transformer, filament
949385-1
94196
3T2
Not used.
3T3
Transformer, adj. core, multiplier output, 110 mc.
8864100-1
204739
3X1 to 3X5
Socket, 7 pin min. 4
737867-18
94879
3X6, 3X7, 3X8
Socket, 9 pin min.
984055-2
94880
3X9
Socket, 7 pin min. Same as 3X1
737867-18
94879
3X10
Socket, crystal, 2 contact, steatite
8885952-1
79970
3Z1
Cavity Assembly (associated parts below)
458907-501
Core, brass tuning core, 5/8-24 thread, 1146- lg., 1Z1 tuning
8831031-1
95393
Contact: beryllium copper, for 1Z1
8834416-1
94390
Pt. of 3C35
Insulator: teflon coated glass fabric, 13'j8" x lin" x .010" thick
8834415-1
94389
Washer, spring, 7/8" OD x 2162- ID x 0.025" thick beryllium copper,
tuning core tension
8831068-2
95394
Nut, hex, brass Y8-24 thread, tuning core locking ?
874927-6
95395
Miscellaneous -
Connector, male, coaxial, cable mtg.
8898625-501
54392
Screw, thumb #10-32 thread, back panel holding
8886111-2
94391
Shield, tube, 7 pin min., 1Y8" lg. ?
99369-1
53016
Shield, tube, 7 pin min., 13/4" lg.
99369-2
54521
Shield, tube, 9 pin min., 13j0" lg. . i
8858642-3
56359
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
3J1
3R40
33
15T IF
CB6
3V/X I
2 HD.
6C B6
3RD.
CBG
3V/X9
0
cv 7
T.O. 31R5-4-A-21
4 TH 1.F
6C56
3 L5
3 x 4
3L1
3R16
22K
2W
DIscR
6 AL 5
3V/XS
5-AFC- 11, AFC-1 2
tt
c.3Le
31t19
3L7
050 UH 2'K
ItE 3"
Z7K
3R18
3C30
1500
3C62
820
?
I. 5
3C50
3LI7
3J5 3C43
10
3C16
4700
3R30
3JS >
27K
53mc OC REACT
12AT7 SANG
3V/X8 3V/X9
3R35
4700
3R68
100K
3C.68
820
470
3L26
66UH
3L2.8
39uH.
31.27
Z. 4%.M.
V6
V3
V4
at co CM?
3L12. 3C28 -DU
2.41)11 1500 2.4011
V
9
4 4 5 4 5
3RG6
3R67
4700 47K
'V\At
ALL CAPACrtOR VALUES GIVEN IN uUF ALL RESISTOR
VALUES GIVEN IN OHMS KT 1/2W UNLESS OTHERWISE SPECIFIED
C -751277-5
Figure AFC-5?Terminal AFC Unit, MI-3/492-C?Schematic Diagram
T.O. 31R5-44-21
AFC- 13, AFC- 14
NOTES'
NUMBERS IN WIRES ARE WIRE NUMBERS (SEE TABLE)
Z. WIRES IN CABLES #4 ANRE/Ve/P1BERS AND oe-sr/A697vows
AT EAGY/ END.
3. WHERE A TINNED COPPER WIRE PASSES TNRU A SOLDER LUG
A HEAVY Dor /ND/CATES TNAT IT SHOULD BE SOLDERED TO THE LUG.
4. SOLDER ALL ELECTRICAL CONNECT/ONS US/NG PT SO,
5. SOLDER LUGS ON COILS ARE DELINEATED FOR COAIYEN/E/VCE IN
SHOWING CONNECTIONS
WIRE TABLE
88 34 402-504
' WIRE No
(ma(IsivE)
DESCRIPTION
R5 NUMBER OR
DRAWING NO.
PARTS LIST
/TEN NO.
Woe hos
NOT USED
CCI OR AND CONDUCTOR
/ TO 7
WHT-BRN /0/0/0
WHT-RED /0,10/0
P5-805-8
PS-1305-8
57
58
/3 70 /6
2/
WHT- RED 7/0/0
PS- e 05- 6
6!
i
24
WHT-YEZ/BLK 7/0/0
NWT 7/7575?
PS- 45 05- 6
PS- s05-6
60
59
27
30
BRAID CABLE 7 2.1,7;TAS3
PS-499-53
SS"
3370 46
1_81.ACX
TINNED COPPER Ase/Rf,m2Lt
As- /05
.57
.57 70 66
/Ns. TUBING .0420.
PS-8
56
0-6366/2 -I
Figure AFC-6?Terminal AFC Unit, MI-31492-C--Connection Diagram
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
MICROWAVE COMMUNICATION EQUIPMENT
eceiver / Modulator MI-31102-B
? TECHNICAL DATA
? DESCRIPTION
? MAINTENANCE
? REPLACEMENT PARTS
RADIO- CORPORATION OF AMERICA
COMMERCIAL ELECTRONIC PRODUCTS, CAMDEN, N. J.
PRINTED IN U. L A.
IB-3322.7-2
517
Approved For Release 2001/03/04 : CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
'AM-1
TECHNICAL DATA
Power Input:
a. Filament Heaters: 35 watts at 115 v, 50/60 cycle ac
b. Plate Supply: 130 milliony. at 250 v de
Frequency Range
2450-2700 megacycles
Receiver Band Width
6 megacycles
Receiver Noise Figure
12 db
I.F. Frequency
30 mc
R.F. Input impltdanee
50 ohms
Carrier Operated Relay Sensitivity
C/N = 12 db max.
Baseband Output for ?I.5 me Peak Deviation
1.2 v rms
Baseband Output Frequency Range
3 kc to 160 kc
Service Channel Output for ?75 kc Peak Deviation
7 v rms
Service Channel Frequency Response
-- 300 cps to 3 kc ?2 db
Service Channel Signal-to-Noise Ratio
(below -?75 kc peak deviation)
35 db
Modulator Input for -?-1.5 mc Peak Deviation
Crystals
Symbol Type
2CR1 1N21B
2CR2 CK705
2CR3 CK705
2CR4 CK705
2CR5 CK705
2CR6 CK705
2CR7 CK705
Tube Complement
Symbol Type
2V1 6CB6
2V2 6CB6
2V3 6CB6
2V4 6CB6
2V5 6CB6
2V6 6CB6
2V7 6CB6
2V8 6036
2V9 6AL5
2V10 6AS6
2V11 6CB6
2V12 6AH6
2V13 12AT7
2V14 12AT7
2V15 6CB6
2V16 12AT7
2V17 12AX7
2V18 12AT7
Function
RP Mixer
RF Rectifier
First Limiter
First Limiter
Second Limiter
Second Limiter
RF Rectifier
Function
First i-f Amplifier
Second i-f Amplifier
Third i-f Amplifier
Fourth i-f Amplifier
Fifth i-f Amplifier
Sixth i-f Amplifier
First Limiter
Second Limiter
Discriminator
Modulator Mixer
70 MC Amplifier
FM Modulator
40 MC Oscillator
Fault Oscillator
Baseband Amplifier
Service Channel Amplifier
Lockout Amplifier
Lockout Amplifier
0.85 v
Relays
Symbol
2K1
2K2
2K3
Function
Receiver Fault
Noise Suppression
Standby Lockout/Loss-of-Signal Remote-
Indication
Weight and Dimensions
Weight-15 lbs.
Height-83A"
Depth back of panel: 21/8"
Depth front of panel: 4"
Width: 19" Rack Mounting
DESCRIPTION
The Receiver/Modulator is designed for mount-
ing in either a standard 19" open rack or cabinet
and is used in both terminal and repeater stations.
The unit has two main functions. The receiver
section amplifies and demodulates the incoming
f-m signal from a terminal or repeater station and
delivers the .3 to 160 kc information to the base-
band and/or service units. The modulator section
provides the transmitter with a 70 mc f-m carrier,
modulated with the .3 to 160 kc multiplex and
service channel signals. In a receiver at a repeater
station the modulation on this 70 mc carrier also
includes the incoming modulation on the 30 mc
i-f signal.
Receiver
In the receiving section the incoming microwave
signal is first converted to a 30 mc i-f. This is
accomplished by mixing the microwave signal with
a sample of the transmitter local oscill?ator fre-
quency. These two frequencies are always 30 mc
apart in accordance with the system plan. Refer to
the system instructions for Typical Systems Fre-
quencies. This mixing is done in mixer cavity 2Z1
which receives the microwave signal through a co-
axial cable from the receiving filter unit. This
cable is connected to cavity terminal 2J1 on the
back of the chassis. A sample of the transmitter
local oscillator frequency is fed by means of a
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
RM-2
STK. NO
54420 2V9 !VS
2V10
244
2J5
2 JS
STK.'NO.
54521
2V15
2RI40
2V15
STK NO.
57533
2VI4
2J13
2.112
2V4 2V1 2V2 2 VI 2 I
7831$
2VII 21148 2V13 2.114 2C I-A 2J7 EVI2 2R115 2JI5 V17 IVIS 2.19 2K3
2C71-13
2C71- C
2J2
2 J3
2K1
291
2TI
RJR
Figure PM- 1?Receiver/Modulator?Front View
coaxial cable from terminal 1J1 of the transmitter
to terminal 2J2, labeled LOCAL OSC., of the mixer
cavity 2Z1. The difference frequency is generated
by the mixer cavity crystal 1N21B and delivered
to the grid of the first 30 mc i-f stage. The screw-
driver adjusting control on the front of 2Z1
resonates the cavity to the correct frequency.
Coupling loop 2J2 couples the local oscillator
energy into the mixer cavity. The 30 mc output
of cavity 2Z1 is amplified by 6 stages (2V1 thru
2V6) of i-f amplifiers to a sufficiently high level
so that proper limiting action can take place in
the two limiting stages 2V7 and 2V8. Each of the
two limiting stages contain dual limiting circuits.
Besides the limiting that occurs in the electron
tubes, additional limiting action is performed in
the circuits containing crystals 2CR3 and 2CR4 of
the 1st limiter stage and crystals 2CR5 and 2CR6
of the 2nd limiter stage. The 30 mc output of the
2nd limiter stage is fed to discriminator 2V9 where
the f-m signal is demodulated and the 300 cycle to
164) kc component delivered to baseband amplifier
2V15. The output of 2V15 is delivered to the base-
hand unit through 2J12-5 at all terminal and drop
repeater stations. A portion of the output of 2V15
is applied to service channel amplifier 2V16. At
stations using a Repeater Service Unit MI-31495 or
Terminal Service Unit MI-31496 the output of 2V16
is supplied directly to the service unit through
2J13-2. At terminal and drop repeater stations
using the indicon service channel system, signals
to Service Channel Unit MI-31140 are supplied by
the baseband unit through 4J3-5. At thru repeater
stations using the indicon service channel system
the output of 2V16 is supplied to Service Channel
Unit MI-31140 through 2J12-5. A connection to
terminal 1 of jack 2J13 from the discriminator out-
put provides the dc amplifier of the transmitter
AFC circuit with the dc correction voltage when
the transmitter local oscillator drifts off frequency.
Modulator
In the modulator section, mixer 2V10 produces
the 70 mc i-f signal which modulates the transmitter
microwave carrier. Amplifier 2V11 amplifies the
70 mc i-f output of the modulator i-f mixer which
is then coupled by coaxial cable to the transmitter
by means of 70 MC OUTPUT jack 2J9. The source
of the two signals that supply modulator i-f mixer
2V10 with its heterodyning frequencies differ for
each type of station as follows:
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
a. At a terminal station the 70 mc subcarrier
output of the modulator i-f mixer 2V10 is the dif-
ference frequency of a 110 mc and a 40 mc signal.
The 40 mc signal is the output of oscillator 2V13
and contains the multiplex and service channel sig.
nals from the baseband unit. The 110 mc frequency
is received from the terminal AFC and is coupled
through a coaxial cable to the 110 MC INPUT jack
2J8 of the receiver/modulator. At terminal stations
only, internal bus connection "P" must be made to
jack 2J8, connection "0" made at jack 2312, coil
2L47 shorted, and connection "L" omitted. (The
letters "P", "0" and "L" refer to connections found
on the receiver/modulator schematic of figure
RM-11.) Adding connection "P" feeds the 110 mc
frequency from the terminal AFC unit to the modu-
lator if mixer 2V10. Removing connection "L" dis-
connects the receiver 30 mc signal from 2V10.
Shorting 2L47 prevents 2V14 from operating as a
110 mc oscillator. Adding connection "0" main-
tains the proper baseband output load impedance
when only one receiver/modulator unit is used as
RM-3
at a terminal station. The amount of baseband
signal applied to 2V12 is determined by the setting
of Modulator Gain control 2R109 which is adjusted
at the factory so that the modulation sensitivity of
all receiver/modulator units will be the dame.
b. At drop repeater stations the 70 mc subcarrier
output of the modulator i-f mixer 2V10 is the sum
frequency of a 30 mc and a 40 mc signal. The signal
from the 40 mc oscillator 2V13 and frequency modu-
lator 2V12 contains the 300 cycle to 160 kc multi-
plex and service channel frequencies added at this
station. The 30 mc signal comes from the receiver
1st limiter stage output and contains the intelligence
modulated on the received microwave signal.
c. The modulator section of a thru repeater sta-
tion is the same as that of a drop repeater station ex-
cept the 40 mc oscillator signal to the modulator-
mixer stage 2V10 contain only 300 cycles to 3 kc
service channel information (voice communication
and fault tone pulses) from the service milt.
In repeater stations the 30 mc frequency 'to the
modulator mixer stage 2V10 comes from the 1st
MULTIPLEX e SERVICE
CHANNEL SIGNALS
F ROM BASEBAND 2JI2-2
0
(4l-2)
MAT I PL Ex (SERVICE
CHANNEL SIGNALS
TO BAsE BAND 2012-5
J 1-5)
FREQUENCY
MODULATOR
(I) 641-16
(2vi2)
a 132
AUDIO TO TERMINAL
SERVICE uNIT(703-2)
OR LOSS-OF-SINAL ,
INDICATION TO SERviCE
cmANNEL UNIT(3J-) \R
:LOSS -OR- SIGNAL
REMOTE-INDICATION
usv AC HI
To TERMINAL
sERV10E uNilt./3. 4624)13-4
SERvICE
CHANNEL
AMPLIFIER
()12477
(vi)
300N TO3KC
BASEBAND
AmPuFIER
(I)GCB6
(2 V 15)
40 MC.
OSCILLATOR
(I) I2AT 7
(aM)
C
MODULATOR
IF MIXER
(I) GASG
(2V 10)
tno Mc P.
70 MC LE
AmPLIFIER
(i)cCB6
(2vi i)
low oRpa TO
2,19 TRANSMITTER
IQ
(us)
J
2.113 FROM AFC UNIT
0-
OC TOCOATROL LOCAL OC
2JI3 -I AFC MO1'012 (ROUTED VIA
SERVICE UNIAJ3-1)
RECEIVER ANTENNA I
2JI INPUT FROM
NIPLEX F ILlc ER
LOCAL OSCILLATOR
FREQUENCY FROM,
TRANSMITTER uNIT
SEE NOTE')
OR TO SERVICE
CHANNEL UNIT
(23JS-4) RECEIVER
RELAY
2K3
(NOTE 2)
30 MC
DISCRIMINATOR
(1)GALS
(2V9)
SQUELCH
TWO 30MC
LIMITERS
(2)6CBG
(2V7e2V0
SIX
30 MC IF.
AMPLIFIERS
()GCBC
(ZVI THRU
2VG)
RECEIVE
R. F.
MIXER
(011421-B
CRYSTAL
(2C RI)
115 V
AC HI
RFLAY
2K2
(SLAVE OF
2K I)
4
FAULT
RELAY
2KI
EQuIPMENT ?TN; DISABLING
FAULT (NS VAC HI)
ac.
AMPLIFIER
(012AT7
(2v14)
LOCKOUT
OIRCuiT
0)12AX7(2 No7)
0)I2AT (2y18)
CRYSTAL
EX705(2ERT)
NOTES:
I-AT STATIONS USING A TERMINAL SERVICE UNIT, rt IS CONNECTED TO 2013-2 e ?R IS
OPEN. AT STATIONS USING A SERVICE CHANNEL UNIT, 'IV IS CONNECTED TO 2013-2
'Q" IS OPEN.
2-RELAY 2K3 IS CONTROLLED BY THE LOCKOUT CIRCUIT.
C 769/3 7-0
TO TRANSMITTER
VIA TERMINAL
uNI1(703-5,?)
OR SERVICE-
CHANNEL (NIT
Figure RM-2?Receiver/Modulator?Block Diagram?Terminal Station
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
Approved For Release 2001/03/04: CIA-RDP79T01049A002600030004-6
RM-4
limiter (2V7) output circuit. Be certain that
internal connection "L" is made when the receiver/-
modulator is used in either a drop repeater or a
thru repeater station and removed when used at a
terminal station.
Operation of Relays 2K1, ZKZ and 2K3
If the i-f amplifier strip fails to function or the
incoming signal fades below threshold or is lost
completely, the positive d-c voltage (from crystal
2CR2 of the 6th receiver i-f stage) normally present
at pin 2 of 2V14 is greatly reduced, causing the
6-7-8 section to 2V14 to conduct.
At a drop or thru repeater station the 6-7-8 sec-
tion of 2V14 is a 110 mc oscillator which supplies
one of the two heterodyning frequencies to 2V10.
The 110 mc frequency is heterodyned with the 40
*mc oscillator output providing a 70 mc frequency
(110 mc ? 40 mc) to keep the transmitter radiating
a quieted carrier. Relay 2K1 in the plate circuit
of the 6-7-8 section of 2V14 is energized when 2V14
starts oscillating.
At a terminal station the 110 mc output of 2V14
is not required. Tube 2V14 is changed to a d-c
amplifier by shorting out plate coil -21.47. When
2V14 is operated by an i-f failure or loss-of-signal,
relay 2K1 is energized.
Relay ZK1 Operation
Contact 3-4 closes, energizing relay 2K2.
Relay 2K2 Operation
1. Contact 2-4 opens, breaking the B+ circuit to
limiters 2V7 and 2V8.
2. Contact 2-3 closes, grounding the plate and
screen circuits of limiters 2V7 and 2V8. This, in
conjunction with the action of contact 2-4, disables
limiters 2V7 and 2V8. With no input to dis-
criminator 2V9 and mixer 2V10, any noise voltage
MULTIPLEX SERVICE
CHANNEL SIGNALS
FROM 645E0 AND 2,J12-2
0
(4J1-2 OR 4.)2-2)
MULTIPLEX (SERVICE
CHANNEL SIGNALS
TO BASEBAND 202-5
FREQUENCY
MODULATOR
???
6.41-16
(2VI2)
Es.
(4.11-5 OR 4)2-S)
2 Jr,13-2
AUDIO TO REPEATER 1.4
SERVICE UNIT (EJ4-2
OR 6)5-2)OR LOSS-OF-
SIGNAL INDICATION
To SERVICE CI-IANNAL IR-
UNIT(23J4-2 OR 23,150
LOSS- OP- SIGNAL
;
REMOTE-viDiCATION
lisv Ac HI
To REPEATER SEInicE L ?
UNIT (G../4-4 oR Go5-4)_2J13-4
oR-ro SERVICE
CHANNEL UNIT
(23.14-4 OR 23)5-4) RECEIVER
EQUIPMENT
FAULT (I 15 VAC 141)
SERVICE
CHANNEL
AMPLIFIER
(012AT7
(2v16)
300K TO=
BASEBAND
AMPLIFIER
60136
(2 V Is)
40 MC.
OSCILLATOR
(I) I2AT 7
(2v13)
110 MC
(NOTE '3)
DC
MODULATOR
LE MIXER
(I) GASC
(2V0)
30 PAC
?
70 MC IF
AMPLIFIER
(I)CCBG
(2v1I)
SEE NOTE1
RELAY
2K3
(NOTE "2)
30 MC
DisCRIADNAToR
(I)GAL
(2V9)
TWO 30MC
LIMITERS
(2) 6C8C
(2%17(20)
SQUELCH
TONIC DRIVE TO
2L/9 TRANSMITTER
0
(1..1
DC TO CONTROL LOCAL
OSC AFC MOTOR
(PoUTED VIA SERVICE
2J13-1 uNIT)4..M.I OR CoS-I)
0
SIX RECEIVER
3omC I.P. R.F
AMPLIFIERS MIXER
(E)6CBG MIN2 I 5
(2 v1 THRU CRYSTAL
2 VG) (EC R1)
113 V
AC HI
RELAY
21