FAMILIARAZATION AND OPERATIONAL EVALUATION OF INFRARED VOICE EQUIPMENT

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03330A000800020014-2
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 3
• Document Creation Date: December 23, 2016
• Document Release Date: May 8, 2014
• Sequence Number: 14
• Publication Date: May 10, 1955
• Content Type: MEMO

Declassified in Part - Sanitized Copy Approved for Release 2014/05/08: CIA-RDP78-03330A000800020014-2
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MEMO FOR THE FILES
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SUBJECT: Infrared Communications Equipment Test
PURPOSE: Familiarazation and Operational Evaluation of Xnfrared
Voice Equipment.
1. During the week of let MAY a trip was made to by 50X1
to 50X1
operate and evaluate the infrared econtunications equipment. The
equipment itself consisted of two package units each package weighing
30 lbs. and consisting of a complete transmitter, receiver viewer,
power supply, and stand. Shown below are a series of drawinga giving
the alze, operational position and controls of the equipment*
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2. Tests began on the morning of arrival at approximately 1100.
Two tests were made at this time, two more in the afternoon and the
concluding two teats were made at 2300. A total of six (6) tests were
made over a 12 hour period covering both day and night conditions.
The tests were all made from the same locations and covered a distance
of 6000 feet from point to poiht. It was not possible to make any longer
tests due to lack of line of sight distances greater than the 6000 feet,
and still retain adequate security. All members of the party aligned
and operated the units.
3. Upon completion of the tests and analysis of results the
eficiencies of the equipment were discussed and the following items
are .to be improved;
STAND AND TURNTABLE
a. The present tubular legs are to be made solid at the joint
location. The slip ring broadened and the tapered part of the leg
which goes under the slip ring will be lengthened.
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Declassified in Part - Sanitized Copy Approved for Release 2014/05/08: CIA-RDP78-03330A000800020014-2
Declassified in Part - Sanitized Copy Approved for Release 2014/05/08: CIA-RDP78-03330A000800020014-2
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b. The springs holding the legs to the turntable were broken in
one case. This was believed due to their having been painted and the
action of the paint reducing the elasticity of the spring. All broken
springs are to be replaced and tested again.
c. The turntable yoke will be reduced in size and weight and a
scale for calibrated settings placed on it.
d. The present thumb screws holding the unit in the yoke will be
replaced by one thumb screw tdom the yoke side of the equipment.
e. The vertical deflection adjust screw will be changed and a
larger knob placed on it.
II. BELLOWS
a. The bleeder on the believe will be increased in size.
b. The bellows will be made of a better material than in preen,.
used. The present material has a tendency to billow and fold wrong
and under usage would crack open.
c. The braces holding the bellows open will be changed to the
sliding type and if possible will have an automatic lock on them.
III. CARRY= CASE.
a. The catches used on the carrying case will be reduced in number
and strengthened.
b. The handle of the carrying case will be increased in am
IV. EQUIPMENT*
a. A front cover for the lead sulphide cell and the viewer will
be provided.
b. A recorder jack will be placed in the equipment.
c. A key input whereby the 1000 cycle tone, may be mores keyed when
the equipment is in the transmit-find position will be added.
d. A shade or cap Will be fitted over the modulation indicator to
provide additional security for night operation.
e. The present volume 'control will be changed from liner to
logmarithmic taper.
f. A sighting device of some types either mechanical or optical
will be added to the equipment.
Declassified in Part - Sanitized Copy Approved for Release 2014/05/08: CIA-RDP78-03330A000800020014-2
Declassified in Part- Sanitized Copy Approved forRelease2014/05/08 : CIA-RDP78-03330A000800020014-2
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4. It was the general consensus of opinion of all embers of the ()
party that the equipment is a very usable item. It meets all require. -?
merits placed on it with ease. A discussion with the TSS man in charge
determined that the equipment can be realigned and repaired by competent
base station personnel. It is our belief that operationally it would
be improved by the addition of a 4 to 8 power scope on the equipment
for daytime operation. Another improvement also would be closer
mechanical tolerance on all moving parts as there is some "pier in
them at present.
5. Operationally it was found that night operation of the equip.
-merit produced optimum results both in quality of the signal and the
time required to aligh the units with each other. This was determined
from the tests when it was found that alignment at night using the
infrared scope to spot the other units beam was accomplished very easily
while alignment during the day using the 1000 cycle note was quite difficult.
At times the note would either be covered by noise or the equipment would
have to be exactly aligned to hear the note, while with the scope the
equipment could be off to a large extent but the .opposite beam would
still be visible for alignment purposes. A much morejprecise knowledge
of the physical location of the unit is needed for the daytime operation.
There is also a much higher background noise level during the day due
to sun and temperature variations, This temperature variation and sun
ambient? also introduce modulation difficulties in that the terrain over
which the beam is established must be of one type. When communications
were attempted over a concrete runway during the day a gravel lis quality
was introduced into the signal making it almost unintelligible. Repeated
realignments of the equipment did not help. When the beam was established
over the earth however the signal improved a great deal. It can there-
fore be assumed that any reflecting surface will modulate the beam to
some extent during the daY:v
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6. This equipment will be available to Commo approximately the
last of August at Which time 20 units will be turned over to us.
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50X1
50X1
Declassified in Part - Sanitized Copy Approved for Release 2014/05/08: CIA-RDP78-03330A000800020014-2