THE EMERGENCY TRANSMISSION FREQUENCY

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03330A004100090042-7
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: January 4, 2012
• Sequence Number: 42
• Publication Date: January 20, 1959
• Content Type: REPORT

Declassified in Part - Sanitized Copy Approved for Release 2012/01/04: CIA-RDP78-03330A004100090042-7
n t l - -
Li U-~ 20 January 1959
C? FI?LNTIAL ? 1) /
There are two so-called "emergency" modes of operation
incorporated into the AS-6 Communication package control circuits.
The first "emergency" mode is frequently referred to as
the "panic" condition. This occurs when the data collector detects a
critical change in the data being recorded and requests the communicg ion
package to make immediate transmission of the stored information to
the base station. The data is transmitted once on each of the three
frequencies selected by the long term programmer every half hour for a
maximum of three hours, or until the transmission sequency is halted
by a receipt signal from the base station.
The second "emergency" mode occurs when a failure is
detected in some part of the communication package. More specifically,
it occurs when the power amplifier fails to tune or deliver power on one
or more of the assigned channels. To help insure reliable communica-
tion a fixed tuned channel is provided in the power amplifier which is
set to one of the assigned frequencies in addition to the servo tuning
also provided for this frequency. This is called the EMERGENCY FR
FREQUENCY or EMERGENCY CHANNEL. It is the philosophy of the
use of this Emergency Channel that the discussion is primarily con-
cerned with .
The original intent was to try each of the three frequencies
(THE EMERGENCY TRANSMISSION FREQUENCY)
normally programmed for a transmission sequence and each time that
CONFIDENTIAL
Declassified in Part - Sanitized Copy Approved for Release 2012/01/04: CIA-RDP78-03330A004100090042-7
 Declassified in Part - Sanitized Copy Approved for Release 2012/01/04: CIA-RDP78-0333OA004100090042-7
'CONFIDENTIAL
failure to tune was noted to switch to the emergency frequency and
transmit there instead. - This would then require that the base station
be provided with an additional receiver rack which could always cover
the emergency frequency since a panic transmission might occur on
the emergency frequency at any time.
The approaches currently in vogue are the following:
1. To always make four transmissions - one of which
is the emergency frequency and cover the emergency frequency with
the base station for 1 hour out of every 3 by the proper programming of
See
the long term programmer. (Insert)
2. To tune up on the emergency frequency after the
normal sequence of three transmissions only if a failure to transmit
occurred on one or more of the normal transmissions frequencies.
Again, the programming of the long term programmer would vaoac cover
the emergency frequency for 1 hour out of every 3.
The last approach is the one which we are currently
constructi-ng equipment for. This approach uses the emergency
frequency the least number of times and conserve battery energy when
no equipment failure is present. Transmission on the emergency
frequency after the completion of the normal operating cycle has one
additional advantage. In the case of interrogation by the base station
it will be possible to predict when the first transmission from the field
unit should have taken place with sufficient accuracy to allow the
receiver covering that frequency to be switched to the emergency channel
INHDENTIAI<
25X1
Declassified in Part - Sanitized Copy Approved for Release 2012/01/04: CIA-RDP78-0333OA004100090042-7
 Declassified in Part - Sanitized Copy Approved for Release 2012/01/04 : CIA-RDP78-0333OA004100090042-7
in time to copy any transmission on the emergency frequency.
Certainly, the solution to the problem that is
currently employed is not an ideal one but it x1cm does appear to have
the greatest number of advantages of any system to date and does not
ax rsex require additional base station equipment.
( Insert)
This would mean that in the event of a failure of the
communication package to communicate on any of the automatically
tuned frequencies during a "panic" transmission the base station
would have the additional possibility of receiving two transmissions
on the emergency frequency during the three hour transmission
sequence.
CON A D FC-EK
Declassified in Part - Sanitized Copy Approved for Release 2012/01/04: CIA-RDP78-0333OA004100090042-7