SBC-1 Evaluation

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-02820A000900010042-5
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 2
• Document Creation Date: December 9, 2016
• Document Release Date: August 3, 2000
• Sequence Number: 42
• Content Type: REPORT

Approved For Release 2000/08/27 : CIA-RDP78-02820A000900010042-5
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ORIGINAL DOCUMENT MISSING PAGE(S):
Approved For Release 2000/08/27 : CIA-RDP78-02820A000900010042-5
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25X1A5a1
5. During the month of January the F.SB projects engineers continued
to evaluate the SBC-1. The following additional fault was found.
a. On received signals, where the suppressed carrier was
weak (but acceptable), noise in the AFC carrier chain caused the
reactance oscillator to shift erratically, causing the audio tone
outputs to shift frequency and thus cause errors in copy.
6. Three units were returned to IBsI from= We were advised by 25X1 A5a 1
that all faults had been repaired.
7. Two of the three units were rejected. The following faults were
found:
a. In one unit there was a noise burst from the AFC which
interrupted copy as described above in Para 5-a. Presumably it
was still coming from the oven.
b. In another unit the sensitivity of the AFC carrier chain
was low, and the unit would not lock in on a suppressed carrier
of -20 db.
c. The third unit was found to be in good operating condition.
8. While examing the units, an additional problem became apparent.
Several failures of the drift alarm amplifier oscillator tube, a 6U8A,
revealed that this circuit was critical enough to require "hand selection"
of the tube. Although not extensively tested, life of tubes in the
circuit seems to be shortened.
9. Conversations with U. S. NAVY personnel based at their receiving
site in Hawaii, revealed that they were having exactly the same problems
with eleven SBC-l's which they were using.
10. The SBC-1 in its present stage of manufacturing is not recommended
as a reliable unit suitable for field use.
25X1A9a
Distribution:
Origina
- Routing & File
- Monthly Report
1
- AES Chrono
1
- Project File
1
-PEI
1-TSB
Approved For Release 2000/08/27 : CIA-RDP78-0282OA000900010042-5