TECHNICAL PROPOSAL SYSTEM 2 FIELD-STATION EQUIPMENT

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP81B00878R000200130002-9
• Release Decision: RIFPUB
• Original Classification: S
• Document Page Count: 6
• Document Creation Date: November 16, 2016
• Document Release Date: August 16, 1999
• Sequence Number: 2
• Publication Date: September 3, 1957
• Content Type: REPORT

Approved For Release 2000/04 81 B00878R0002001300
VOLUME2
TECHNICAL PROPQSAL
FIELD-STATION EQUIPMENT
3 September 1957
CMCC Document No. 1133X5.45
Copy 1 of 6 Copies
s~PC /~ ~(~{,
COPY / OF ~'
:,(This document contains a total of 6 s.heetsy
including this title sheet. )
DracUnneNT rvo!~'
fS0 C!-fANaF iN CLASS
C7 DECLASSIFIED
GLASS. C4iANCED Td. TS S C.ry ~ ~~
iJEXT D,G~JIEVV DATE: 4
AUTtI: HR 70-
Approved For Release 2000/0 ~~~~Q0~~1~~~~36~1 26 =~'
This docemenl cenfoins infermaflen eflecfinp the nefionol dsf~nse of the United Slates within tha meaning of the Espione9e lows, Tlfle
1B, U.S.G., Seclien 79~ and 704, the tronsmisston er nvelafion el which in any manner to an enoolhorised parson is prohibited by law.
 Approved For Release 2000/0 ~ 1 B00878R000200130002-9
1. Scope
A proposal is presented for the adaptation of the existing
System 2 airborne equipment to a field=station communications
equipment. Since there is no longer a need for the System 2
navigation features, this proposal provides for the removal of
these. features. from the System 2base-station receiving
.equipment.
2. Description of the Existing System 2 Equipment
a. .System 2 is a long range digital communication. system
and ground based navigation system operating ixx t:he high=
frequency band and includes both airborne and ground-based
equipments. An air~to~ground or graund~to-air message
consists of a group of four decimal digits transmitted as a
short burst of .frequency-shift coded pulses. Received
messages are automatically printed out by a small tape
printer in the receiving equipment. The system employs
.automatic message recognition features w:hic:h provide
discrimination against the effects of atmospheric noise and
interfering radio signals. The ground~to=air communication
function, includes a discrete address function by which a given
airborne equipment prints only messages addressed to it. T:he
meanings of the decimal digit message units sent and received
=are contained. in code books :held by both parties and a given
decimal digit group may be assigned any desired meaning.
b. The System 2 airborne equipment was designed for
maximum simplicity of operation. The controls consist of an
off~on switch, frequency-channel selector switch9 three 1Q-
position message-selection switches and. a press~ta-transmit
button. which causes the selected message group to be
automatically encoded and transmitted. A fourth decimal
digit, which identifies t:he originating. aircraft, is automatically
inserted in messages. transmitted by the airborne equipment.
Approved For Release 2000 P81 B00878R000200130002-9
This document confoins Informeflon affecllnp the nelionel defense of tha United States wilhln the mooning of the Espionage lows, Tllle
18, U.S.C., Section 74~ and 794, the Ironsmission er revelelion of which in any manner fo an uneuthorixsd person Is prohibited by law.
 Approved For Release 2000/ 008788000200130002-9
c. Each base=station equipment consists of a transmitting
and. a receiving. equipment designed to operate at separate
sites. The .base.-station receiving equipment is housed in a
double cabinet which contains electronic assemblies for both
communication and navigation functions plus a small cabinet
containing power supplies.
3. General Requirements
A requirement exists. for a field~statian communication
equipment for use between fixed field stations and base
stations. This equipment must be packaged so that it can be
broken-down for- shipment in packages no larger than an.
ordinary communications receiver and which when assembled
and adjusted by trained technicians can be operated by untrained
personnel. T.he equipment must be flexible with regard to the
layout of the particular installation and with-regard to use of
whatever antenna is available. Unattended reception of incoming
messages is required. In addition, early availability of
equipments for operational use is an important requirement.
4. Structure of the Proposed Field=Statipn Equipment
a. .The System 2 airborne equipment possesses many of the
features required of the field-station equipment. The units of
the airborne equipment are packaged in extremely compact
form using miniaturized electronic circuits. The operating
controls. are extremely simple and are designed for the use of
a pilot of a single=place aircraft. Unattended reception of
messages is provided.
b. The proposed field=station equipment is based on the
maximum use of existing System Z airborne equipment designs
and concepts to minimize development costs, to provide
earliest possible delivery of equipments, and to utilize System 2
electronic and fabricated parts in production surplus. to the
greatest possible extent.
^
Approved For Release 2000/ B00878R000200130002-9
TAIs document conleins informelion offecfing the national de/ense of fhs Unifad States within the meaning of the Esplonega Laws, Tttle
IS, U.S.C., Section 793 and 794, Ih? transmission or rsveletien of which in any manner fo an unauthorized person is prohibited by law.
 Approved For Release 2000/04/ 1 B00878R000200130002-9
c. This equipment consists of three separate packages,
The main cabinet contains the rnajar. electronic assemblies,
a table-tap control bax.at the operator's position, and the
antenna coupler which will be placed at the antenna terminal..
d. The control box is a new design in which message
selection is accomplished by afour-column, 10-row keyboard
housed in a sloping-front table-top cabinet which will also
contain the printing unit, channel-selector switch, and press-
ta-transmit bar, The System 2 printing unit wall be xnadifi.ed
to facilitate loading, permit the tape to feed out, and ixa.crease
paper capacity.
e. The main cabinet contains t:he following unitse
(1) Receiver -- present System 2 design.
{2) Communication Unit -~~ present System 2 design
modified to permit operator selection of all faun
transmitted message digits and to improve circuit
performance. These modifications are based an field
experience with the- System 2 equipment and ca:nsist of
changes to the .counter and gating circuits which wall
make switching-pulse amplitude less critical., eliminate
base-clamping da.odes, and combine supply voltages for
flip-flops and their associated emitter followers.
(3) Exciter ~~- present System 2 design.
(4) Transmitter -- present System 2 circuit repackaged
to use conventional panel and chassis structure, wlxl.ch
permits replacement of the servo-tuned plate network,
with a band?,switched arrangement. The present 400-
cycle input high-voltage power supply will be replaced
by a 4570 cycle, 115230 voltage ~ 10% innput power
supply.
Approved For Release 2000/0 81 B00878R000200130002-9
This document confolns Information offacling the nalionel defense of the United States within the meaning of the Espionage lows, Title
18, U.S.C., Section 79~ end 791, fha Transmission or revelation of which in any monnar fo an unoufhorited parson is prohtblted by law.
 Approved For Release 2000/0 1 B00878R000200130002-9
(5) Power Supplies mo new design to provide the
necessary operating voltages from 4570 cycle,
115230 volt ? 10% primary power instead of 400
cycle primary power.
(6) Main Cabinet Assemblies m- new design to
provide the necessary mounting structures, air
cooling system and interconnection of units in a
customer=furnis:hed demountable rack.
f. The antenna. coupler will be the present System 2 design
modified by replacing. the complex pressurized structure .with
a simple weatherproof case.
g. Cables. wild. be provided as required for interconnecting
the major units and for primary power. Twelve feet of
cable will be provided between the main cabinet and control box
and, fifty feet of cable between the main cabinet and antenna
coupler. Twenty feet of primary power cable will. also be
provided.
5. Base~Station Receiving Equipment Modification
a. .The elimination of the requirement for navigation service
permits. rexnaval of electronic assemblies in the base~statian
receiving equipment associated with t:he.navigation function.
and their replacement by an additional set of communications
chassis to provide a dual communication. receiving equipment.
Operating. controls for this equipment will be brought down to
seated height as part of this rearrangement and digital circuit
modifications, similar to those to be made in the field
station communication unit, will be made to provide improved
performance. T:he remote operation unit,. which provides
control of the transmitting equipment from the base=station.
-receiving equipment, will be equipped with a l0~key message
selection panel to facilitate operation,
Approved For Release 2000/0 1 B00878R000200130002-9
This document centoins informotian affsctinp the nelionol defense of the United States within fhe -meaning of fhe Espione0e laws, Title
18, V.S.C., Section 703 and 704, fhe Ironsmhsloa er nvdeflon of which in any manner to an unauthorized person is prohibited by law.
 " Approved For Release 2000/Oar~~?~~1~b~1 g00878R000200130002-9
~~ ~::~~ ^
6. Protect Program
a. Preliminary design of the new units. and modifications
covered in this exhibit have already commenced under a
previous authorization,
b. Two deliverable prototypes of the field station
equipment will be constructed as part of the engineering
effort. The first prototype will be available for field
.testing on 30 December 1957. Production assembly beyond
the two. prototypes of the redesigned transmitter, new
control box and new cabinet and cable assemblies will not
commence until prototype evaluation has been completed
on 1 February 1958. Production assembly of the other
equipment units. and purchase of electronic and fabricated
parts for the redesigned and new units must commence
about 1 December 1957 to meet the delivery schedule
indicated in Volume 1 of this proposal.
c. A prototype of the base station dual receiving equipment
utilizing electronic chassis in production for the two guard=
band receiving equipments,. will be constructed as part of
the engineering program. As indicated above, this prototype
equipment will be available for delivery and evaluation on
30 December 1957.
d. Modification of the base=station equipments presently
in the field will be accornplis:hed by producing and delivering
two field modification kits which will include completely
wired double cabinets to w:hie.h existing. chassis will be
. transferred. Printed circuit assemblies will be returned to
the. factory for`rnodification. As an alternate approach,
complete base station receiving equipments may be returned
to the factory for modification.
Approved For Release 2000/ ~ 1 B00878R000200130002-9
Thic de