GENERAL: TA-1 TRANSMITTER SPECIFIC: MODULATOR (PROJECT 2515)

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03535A000600060004-4
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 9
• Document Creation Date: December 22, 2016
• Document Release Date: June 12, 2012
• Sequence Number: 4
• Publication Date: February 28, 1957
• Content Type: MISC

Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
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I-TRANSMITTAL SLIP V"' 9
FORM NO . n A 1 REPLACES FORM 36-8
rcn as 24 WHICH MAY BE USED.
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 Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
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 Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4 - -
The Files
General: TA-1 Transmitter
Specific: Modulator (Project 2515)
28 February 1957
used with any receiver, the TA-1 and receiver comprising a com-
plete radio station. The receiver supplies power to the TA-1 and
the final audio tube in the receiver is extracted and inserted in-
to the TA-1. This tube becomes the transmitter. Built into the
transmitter case is a transistorized oscillator that can serve as
a bfo in receivers lack such a eta In its present form,
the TA-1 can only be used
Il+~I RODUCTION :
The TA-1 Transmitter was designed to be
MISSION ASSIGNMW :
External Projects Section requested that an attempt be made
to design a modulator for the TA-i. EP placed no restrictions on
the size of the modulator and did not specify that it should be
either an integral part of the transmitter or a separate unit.
DISCUSSION :
25X1
25X1
The modulator for the unit may be made an integral part of
the transmitter by eliminating the modulation transformer normally
used, and by keeping the number of components to a minim. The
hand key and bfo circuitry would have to be removed to make room
for these new products.
Figure 1 in the appendix shows the circuit developed. This
circuit performed satisfactorily but has one serious fault. If
the transmitter tube is removed or the fill nt opens, the transis-
tor (953) might be damaged due to the increase in collector voltage.
The modulator may be made as a separate unit. The circuit shown
in Figure 2 should modulate the transmitter 60 to 75 percent. Two
r c bled would be necessary. One cable would be used forF-1 25X1
on TA -1 transmitters now in the field could be made vithoutftV
difficulty. A separate modulator unit would not appreciably increase
the weight or size of the completed unit.
kAF Nlb~ k an~n,',aR.~n, -4==~ 2(J/ b cmQ, .6GSr ON
I OHIO Cut! Pe ::a lb
IWASOH S ~ (3) JUST 1,itr.%`f er S
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 Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
IL
The more sates factory way to ate the transmitter is to
create a separate modulator unit. A separate unit creates no
hazard to the final transistor; its Installation is s
so that a field station could adapt it to existing t enough
matters. TA - tzs-
'.CAC : Appmdix
Lab/NCC/bao (28 Feb 57)
Distribution :
Original. ,- Lab Files
1 - Ilev/s
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 Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
-APPENDIX
2N43
2N34
953
PUSH TO TALK
-c-100
KEY B- 0+ SCREEN
GRID
FIG. I
PRESENT CIRCUIT OF TA-I MODULATOR
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 Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
2N43
211434
IOK:50K
.g+
FIG. 2
PROPOSED CIRCUIT FOR TA-11 MODULATOR
--0
SCREEN
ORID
Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
 1:1Y _xv~ u ua I l ._ _ -.J 1
Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
RS
c6
C5
C2
P-4, K 1/2 W
1.6 K 112 W
7O cbm 1/2 V
2.7 K 12W
6B x I/2 W
147 K 1/2
x00ob 1f2W
6.2 x 1/2 W
43K 2A
151 obm 1/2W
39X IV
33K 1/2W
K 1/2w
4.7K 1W
47 K 2 W
100
2$ of
.03 uf
zu
l
4vIC TAW
10 Volta
8 volts
4oo v
200 V
300 V
10 V
Maoz M2 2!!.06
952
(I)
Ti Ji) Dort 17
S1 1) = Tquae Switeb
Ins u n s
Temms Inst u1e
d ati aml c auc C
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 Declassified in Part - Sanitized Copy Approved for Release 2012/06/12 : CIA-RDP78-03535A000600060004-4
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