AUDIO OSCILLATORS, IN-1 AND IN-9

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03535A000500040025-4
• Release Decision: RIPPUB
• Original Classification: S
• Document Page Count: 5
• Document Creation Date: December 27, 2016
• Document Release Date: September 13, 2012
• Sequence Number: 25
• Publication Date: December 12, 1958
• Content Type: MEMO

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Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040025-4
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FROM:
OC-SP/EA
No. 25)
SPM 8-882
DATE
12 December 1958
TO: (Officer designation, room number, and
building)
DATE
OFFICER'S
INITIALS
COMMENTS (Number each comment to show from whom
to whom. Draw a line across column after each comment.)
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Declassified in Part- Sanitized Copy Approved forRelease2012%09/13 : CIA-RDP78-03535A000500040025-4
(-)
Office Memorandum ? UNITED STATES GOVERNMENT
ti?WW111.1
TO : Chief, Engineering Staff, OC
FROM : Chief, Special Programs Staff, OC
SUBJECT: Audio Oscillators, IN-1 and IN-9
REF : Memo ENG-M8-1204, dated 12 November 1958
SPM 8-882
DATE: 12 December 1958
1. Transmitted herewith is the operational evaluation of the
IN-1, audio oscillator. A review of current operational requirements
indicate that nine (9) each units are required to fullfil REINT
commitments. It is requested that a locking device be incorporated
in the nine units to prevent accidental mietuning. This feature is
described in the evaluation report, paragraph III.
The use of the IN-9 against a system with a PRF of 10 Kc/s
could generate a readout error of 400 cycles and confuse the analyst.
It is felt that the accuracy of the IN-9 is not adequate to satisfy
current operational requirements for a reference tone oscillator,
therefore, fabrication of additional IN-9 units is not requ4ste4.
Attachment:
As stated above
Distribution:
N.Orig & 1 w/att - Addressee
DOCUMENT NO.
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C.) SEMI c.)
IN-1 AUDIO OSCILLATOR
I. 3.2222.E1L192
The IN-1 Audio Oscillator is a self-contained battery operated
unit which supplies a pulse output with repetition rates variable
from 30 to 3000 cycles per second. A Veer-Root type dial, with a
numerical range from 000 to 999, is used in conjunction with a
calibrated chart to indicate frequency. Two output jacks are pro-
vided to permit simultaneous record and aural monitor.
s
II. Tests Performed
The following tests were performed on the oscillator:
a) frequency stability
b) dial accuracy
c) dial resetability
d) mechanical inspection
The frequency stability of the unit was measured using a Berkeley
Counter at frequencies chosen at random. The measurements were made
over a period of five (5) to ten (10) minutes at room temperature only.
The dial accuracy check was also made at room temperature using the
frequency counter. The dial was set for a specific frequency, as deter-
mined from the calibrated chart, and the actual frequency was then read
on the counter. The dial resetability test WAS performed after an
elapsed time of twenty-four (214) hours, and consisted of resetting the
dial to the original position and measuring the actual frequency. The
results of these two tests are tabulated in table I. A mechanical in-
spection was made to determine the need for any changes to improve
operational use of the oscillator.
SECRET
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,sp
IN-1 AUDIO OSCILLATOR
3 December 1958
Page 2 .
III. Conclusions and Recommendations
The frequency stability of the audio oscillator was found to be
very good, with the stability well within 1% at the frequencies
checked. No frequency stability measurements were made at other than
room temperature because of insufficient time available for test.
The dial accuracy and the dial resetability are good enough for the
operational usage intended for the equipment. The mechanical design
of the unit appears to be rugged and capable of withstanding any
anticipated rough handling. One of the features of the oscillator
is its ability to be tuned with very slight pressure applied to the
knob. While this feature may be desirable in many cases, it has the
distinct disadvantage of being able to be moved unintentionally. It
is recommended that a locking device be incorporated to permit holding
the tuning knob at a specified frequency.
Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040025-4
Declassified in Pari-- Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040025-4
SP4itt71 c.)
TABLE I
Dial Reading
Frequency (Chart)
(Cps)
Frequency (Meas.)
(Cps)
Fr eq. (Meas.)
Band A
30.0
30.2
307.5
352.0
140.0
40.0
39.9
507.5
50.0
50.4
50.3
60E7.5
604,0
60.5
60.4
677.5
70.0
70.)4
730.0
80.o
80.3
772.5
90.0
90.5
90.1
807.5
100.0
101.2
101.0
907.5
150.0
152.0
957.5
200.0
202.7
203.0
987.5
250.0
2514.2
253.9
Band B
47.5
300.0
303.6
303.14
295.0
400.0
395.6
395.5
465.o
500.0
501.6
501.3
572.0
600.0
604.0
602.14
647.5
700.0
699.5
701.14
702.5
800.0
795.3
798.5
7145.0
900.0
879.0
890.2
782.0
1000.0
983.6
992.9
887.5
1500.0
1464.o
11470.0
942.5
2000.0
1954.0
1959.0
977.0
2500.0
21468.0
21469.0
999.0
3000.0
2979.0
2977.0
Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040025-4