VARIABLE FREQUENCY AUDIO OSCILLATOR, IN-1

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03535A000500040014-6
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 3
• Document Creation Date: December 27, 2016
• Document Release Date: September 13, 2012
• Sequence Number: 14
• Publication Date: July 1, 1959
• Content Type: MISC

Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040014-6
2510
.).Variable Frequency Audio Oscillator, IN-1
This device provides a variable frequency audio tone in the frequency
range of 30 to 3000 cps. The frequency of this tone must be accurate
to within + 27. over the temperature range of 0?C to 55?C. The physical
size of the oscillator is important since it must be carried concealed
on the person: In a typical application, an operator would determine
pulse repetition rates of enemy radar by aurally comparing it with the
tone of the IN-1.
30 to 3000 cps in two bands
xxxxxx source: Self-contained 22.5 volt battery
Approximately 10 ohms
xxxxxitotixxxxxx
Frequency Stability: Better than + 2% over the temperature range of
xxxxxxxxxxxxxxxxxx -40? C to 453?C and a supply voltage variationi
of 15 to 30 volts.
this *mimeo fs port of an Irdograted
file. U soparated from Mt flit it must kit
Sukfected to fotrwidual systematic RAM'
5 x 2 7/8 x 1 1/4 inches
Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040014-6
Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040014-6
1 lb.
The IN*1 is an accurate, mitgature source of audio
frequencies for aural comparisons.
The small SiZe of this unit makes it ides
STAT
No training beyond an explanation of its functions
with collection devices is required to operate the IN.A1.
No field maintenance is contemplated other than battery
replacement.
Three prototype models of this oscillator have been designed. The first\
model used a vacuum tube and was dropped because of high power consumpti4
The second model was transietorized and met the electronic specifications
but the mechanical features were not rugged enough to maintain the
alignment necessary to insure the required tolerances on resettability.
The size objectives were then relaxed to permit redesign to remove the
mechanical deficiencies. in the meantime a new and much smaller
potentiometer became available which showed promise of making possible
a considerable reduction in size. However, closer examination revealed
that the cost Juts of redesign mould outweigh the advantages of the size
reduction obtained and the fabrication of the larger unit was commenced.
Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040014-6
Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040014-6
t?
t the fabrication of 9 units.
Photographs are the same a Piguree 84 and 85 in the last
annual report.
None
Une lass.
Declassified in Part - Sanitized Copy Approved for Release 2012/09/13: CIA-RDP78-03535A000500040014-6