TECHNICAL REPORT ON COLLINS REMOTE RECEIVING SYSTEM

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP82-00803R000300250002-7
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 10
• Document Creation Date: December 20, 2016
• Document Release Date: March 25, 1999
• Sequence Number: 2
• Publication Date: July 26, 1998
• Content Type: MEMO

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 OPTIONAL
MAY 1963 "'EC Approved For Release 2007/07/25: CIA-RDP82-00803R000300250002-7
OP FPM2 (41 CF.1 101-11,6
UNITED STATES GOVERNMENT
TO : Chief, Operations Group, L
FROM : Chief, Engineering Staff,
SUBJECT: Technical Report on Collins Remote Receiving System
DATE: 15 July 1971
1. Since 27 January 1971 the Collins Digital Remote Receiving
STATSPEC System has been under test between =]Headquarters and the STATSPEC
STATSPEC receiving; site, utilizing the rhombic antennas located there.
Over the twelve-month period prior to the tests, development of the
Memorandum
Collins Equipment was monitored by the
Engineering Staff and with
the cooperation of Collins Radio Company, unique requirements for
operations were designed into the system at no cost to
2. The system as tested between FBIS Headquarters (primary site)
STATSPEC and the remote site) consisted of the following equipment:
an 2 each, 65151 Collins, Solid State Receivers with direct electronic
frequency read-out at the remote sites
b., 1 each, 8311B-1 Collins Processor for controlling and tuning
receivers at the remote site.
c. 1 each, Crown Tape Recorder with special control interface
located at the remote site*
d. 2 each, t'1odel 33 Teletype machines, with appropriate modems, one
located at the remote site and one at the primary sites
e. 1 each, Contxrol Head, 514S-1, located at the primary site,
f, To sin'ulate a field bureau monitoring; installation a FSK
converter, model 28 KSR teletype machine,, monitor amplifier
control panel and IBM recording equipment were installed
in the pry site location in the Key Building.
3. The system is designed to remotely control receivers, antenna
matrices, audio lines and recording equipment from a distant point. The
control commands are relatively simple functions from the model 33 teletype
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keyboard or digital cc lands generated by movement of the control knobs
on the remote control head (5145-1) and transmitted to the 8311 processor
at the remote site. The processor in turn controls the devices can-
prising the system. Digital control information between the primary and
remote sites is transmitted in the form of eight-level ASCII code char-
acters at a bit-rate of 110/BPS. This relatively slow bit-rate requires
no special conditioning of the control line and use of a standard tele-
phone circuit is more than adequate as verified in the test. The audio
intelligence from the receiver is returned to the primary site via a
voice-quality circuit. During the tests, a 5-kHz voice-quality cry lit
was utilized between l ~nd Headquarters t however tests verified a 4-kHz
circuit would be more than adequate for returning the voice information.
4. The 6515-1 is a canpletely solid state, triple-conversionv super-
hetrodyne receiver which provides coverage from 400-kHz to 29.999 MHz.
Primarily the 6515-1 receiver is a general purpose instrument hm?ever,
for remote operations features are provided in the receiver for the in-
stallation of two additional printed circuit cards. For operation,
in addition to the existing bandpass filters, a 2.7 kHz iflter was in-
stalled to improve the performance of the receiver for standard AMA-voice
pletely fulfills this requirement and simultaneously restricts the band-
width to permit multiplexing of the control circuit on a 4 kHz voice
circuit. During the tests? the performance of the receiver exceeded
specifications and no failures were noted. A detailed technical manual
on the 6515-1 receiver will be available fry n Collins Radio in the near
futuree
reception. Experience gained by 0 during the past years has shcran
that optimum bandwidth for short-wave voice monitoring is approximately
3 kHz. The use of the 6515-.1 receiver's 2.7 kHz bandpass filter cc
- 2 .-
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5, TECINICAL TEST RESULTS. Evaluation of the Collins remote equip-
ment has been beneficial to both ~Engineeri.n; Staff and the manu-
facturer. Considerable experience in the operation of a remote system,
the equipment required, reliability and programming possibilities was
collected during the tests*
a. One major design fault in the construction of the processor.
power supply and a minor problem with the end-of-tape sensing device
caused ninety-five percent of the malfunctions in the equipment during
the test. On eight separate occasions the 83113-1 processor went into a
locked condition and failed to control the receivers and other equipment
at the remote site. This condition could be rapidly rectified by me nen-
terily removing power from the processor and then restoring it. A com-
plete investigation of the problem revealed transient voltages were reach-
ing the processor power supply from the conmuuiications lines and electrical
power system. The sensing circuits in the power supply detected these
transients as over-voltages or under-voltages and in turn attempted to
sequence the power supplies off. The processor supply was redesigned by
Collins Radio and an improved power supply installed in the processor on
6 July. The lock-up condition has not occurred since the new power supply
was installed.
b. On several occasions, the magnetic tape on the recorder was
completely rewound onto the start reel during the rewind cycle. The prob-
lem occurred because the end-of-tape sensing device failed to detect the
specially treated end-of-tape section. Investigation revealed that one
adjusting screw had been omitted during fabrication or had been lost
during shipment. Replacement of this screw and adjustment corrected the
r. lfunction.
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c. During the technical tests it became evident that one major
system improvement could be made to drastically reduce the cost of com-
minications lines for the system, especially when long distances are in-
volved between the primary and remote sites. The present system requires
one full-duplex line between the two sites which serves as a control line
between the teletype machine, control head and the processor at the re-
mote site. Only one control line is required regardless of the nurser
of receivers being controlled. However, over long distances, the cost
of the control line can be substantial because it must be assigned at all
times in the event a command is required between the two sites. Pre-
liminary tests and calculations indicate the control pulses can be trans-
mitted to and from the remotA_ processor on the same line used to ret=i
the audio intelligence from the receiver. The system of Speech-Plus is
car=nly used to transmit at least one teletype circuit, in this case the
control pulses, and a voice transmission over the same circuit. Tests to
confirm the operation of the system using one line for both voice and con-
trol pulses were under way when it became necessary to release the equip
meat for operational use. These tests will be continued when the equip-
ment is again available for experimental work" The problem of a separate
voice line and control line is not a critical one when short distances
involved between the two sites. Anticipating that remote equipment
will be very useful for covering denied areas via satellite communications
and with the advent of the assign-on-darand system presently being in-
stalled in the INTELSA'C cannon carrier circuits, efforts to combine the
voice and control information into one circuit is a worthwhile approach.
The primary advantage of the assign-on-demand system is the subscriber
pays for the circuit only during the time it is being used. The assiE,
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STATSPEC
STATSPEC
on-demand system as it affects l operation will be covered in a
separate paper in the near future. This assign-on-demand system is
considered by many in the cc nunications field as a. revolutionary step
towards reducing communications costs,
d. Because of a critical requirement to operationally monitor
a Time Division Multiplex circuit, all tests and reconfiguration ,work
on the Collins Remote System were terminated on 1 May 1971. However it
is anticipated that additional technical tests and modifications will
result in additional price reductions and a system which meets the specific
requirements of However, the system in its present configuration
is well adapted for _ usee
e. During the operational tests a number of programming improve-
merits were suggested by
id Engineering personnel. The programming
chacnges are being studied and where practical without major software
changes which would result in a large expenditure of funds, the changes
will be incorporated in the system intended for use at the
STATSPEC f. After a short training session for
personnel, a con-
STATSPEC
certed cruising program was conducted until mid-March. At that time ex-
perienced voice monitors were instructed in the operation=-cf the equipment.
These monitors made use of the equipment for several weeks in a live
monitoring experiment. Turing; late March and early April 1971, numerous
demonstrations were held for members of the intelligence corm pity, in-
cluding DIA and NSA as well as components of the Agency. The equipment
STATSPEC w,
s demonstrated to more than l0Q ~mployees, many of whom were not
acquainted with the equipment and techniques involved in voice
monitoring.
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6. Thel F ineering Staff extends its sincere appreciation
to Collins Radio personnel for their complete cooperation during the
tests. Also' personnel in the Office of Communications contributed to
the test by making available to the two 6515-1 Collins receivers
used in the system.
7. A block diagram of the system configuration is attached,
Attach:nent - 3 pages
Distribution:
Ch/Ops - 2
0/Dir = 1
0/Cameo - 1
Collins - 1
ES - 2
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