OPERATING NOTES AND INSTRUCTIONS FOR THE 1000 CPS FIXED FREQUENCY REFERENCE OSCILLATOR, IN-9

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03535A000500040020-9
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 11
• Document Creation Date: December 27, 2016
• Document Release Date: September 13, 2012
• Sequence Number: 20
• Publication Date: April 25, 1958
• Content Type: REPORT

Declassified and Approved For Release 2012/09/13: CIA-RDP78-03535A000500040020-9
OPERATING NOTES AND INSTRUCTIONS
FOR THE
1000'CPS?FIXED FREQUENCY REFERENCE OSCILLATOR, IN-9
?
This ? document Is part of an Integrated
ide. If separated train the file It must tr4 ?
Winded to Individual systematic roviorzu I
DATE: 25 April 1938
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TABLE OF CONTENTS
I. GENERAL DESCRIPTION
II. CHARACTERISTICS
Page
1
2
2.1. Electrical
2
2.2. Physical
2
III.. OPERATING INSTRUCTIONS
3
3.1. Controls and Terminals
3
3.2. Operation of -the Instrument
4
3.2.1. Local Operation
4
. 3.2.2. Remote Operation
4
3.3. Power Supply:
IV. CIRCUIT DESCRIPTION
6
V. MAINTNNANCE
7
COMPONENT LIST
9
Schematic Diagram
10
-Figure 1
11
Figure 2
12
Figure 3
13
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I. GENERAL DESCRIPTION
The IN-9 is a self-contained battery-operated audio oscillator
providing relatively stable short duration pulses at a frequency
of 1000 cycles per second. This unit was developed primarily to
be used in place of the more stable tuning fork reference oscil-
lator (IN-3) in applications where small size is more important
than extreme accuracy. A socket has been provided so that the
unit may be powered and/or controlled from a remote location.
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0 0
2.1. Electrical
Frequency
II. CHARACTERISTICS
: 1000 cps
Frequency Stability: Better than plus or minus 2 per cent over
the temperature range of minus 40 degrees
to plus 55 degrees Centigrade and a supply
voltage variation of 15 to 30 volts.
Output Waveform
Warmup Time
Power Source,
Pulse
None
: Self-contained 22.5 volt battery. Eveready
type 412E or Burgess type U15. In a remote
power setup the voltage may be between 15
and 30 volts. The current required will
vary between units but should be no greater
than 3 milliamperes at 22.5 volts.
Load Impedance : The load should be 1000 ohms or higher.
Output Voltage : Continuously variable. The Maximum peak pulse
voltage will be approximately equal to the
power supply voltage.
2.2. Physical
Weight : 5 ounces, including battery
Dimensions: 3-5/8" 2-1/4" x 3/4" over-all
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III. OPERATING INSTRUCTIONS
3.1. dontrois and Terminals (See Figure 1)
COVER FASTENING SCREW: This screw holds the cover in place.
AMPLITUDE
: This control is used to vary the amplitude
of the voltage appearing at the OUTPUT con-
nector. A switch is ganged with this con-
trol and is actuated when the control is
rotated fully counterclockwise. This
switch disconnects the internal battery
from the KEY button and prevents the bat-
tery from being discharged if the KEY
button is accidentally mssed while the
instrument is being carried or stored.
OUTPUT : The output voltage of the instrument appears
at this connector.
KEY
REMOTE
This button Connects the battery to the
oscillator. A switch on the ANPLITUDE con-
trol must be turned on before the KEY button
will function. Pressing this button causes
the signal voltage to appear at the OUTPUT
connector.
This connector may be used to control the
instrument and/or supply power from a dis-
tant point if necessary.
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3.2. 921.E.9AkPla
3.2.1. Local Operation
a. Remove the cover by loosening the COVER FASTENING SCREW and
sliding the cover off:
b. Place a 22.5 volt Eveready 412E or Burgess U15 battery in the
battery holder (See Figure 2). The correct battery polarity
is marked on the case.
c. Replace the cover.
d. Rotate the AMPLITUDE control 270 degrees clockwise. This will
connect the battery to the KEY button and at the same time
place the maximum oscillator voltage amplitude across the OUT-
PUT connector when the KEY button is pressed.
e. Connect the load to the OUTPUT connector (see paragraph 2.1.f.).
f. Set the AMPLITUDE control for the desired voltage amplitude to
the load.
3.2.2. Remote Operation
a. Pins A, B, and C of the REMOTE connector are connected in the
following manner:
Pin A - negative side of battery
Pin B - positive side of battery
Pin C - chassis.
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b. If it is desired to use the internal battery but control the
signal from a remote point connect a remote SPST switch to
pins A. and C.
c. If it is desired to use an external battery and local KEY
then connect pin A to the negative and pin B to the positive
side of the remote battery.
d. If it is desired to use both an external battery and key
connect the remote switch between pins A and C and connect
the positive side of the remote battery to pin B and the
negative side of the remote battery to pin A.
3.3. Power Supply
Type:
The self-contained power supply is a 22.5 volt Burgess type
U15 or Eveready type 412E battery. A remote plover supply
must be capable of supplying 15 to 30 volts at a maximum
current of approximately 3 ma.
Life:? Power is required only during the time that the KEY button
is pressed. Under these conditions the battery will have
exceptionally long life. Because the unijunction tran-
sistor parameters vary from unit to unit the current drain
will be between one and three milliamperes.
If it is assumed that the oscillator is on continuously with
a current drain of three milliamperes and the battery is use
to a voltage of 15 volts the life of the battery will be
about 25 hours. In any case the battery should be removed
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C)
when the terminal voltage under load drops to 15 volts.
Remove the battery if the instrument is placed in storage.
IV. CIRCUIT DESCRIPTION
The circuit is composed of a unijunction transistor relaxation
type oscillator followed by a transistor grounded collector ampli-
fier to isolate the load from the oscillator.
The frequency of oscillation.is generally determined by the time
required to charge Cl to a potential equal to the "breakdown"
potential of the unijunction transistor. This capacitor is
charged by the battery through the parallel paths provided by
the external resistances R1, R2, and R3, and the back resistance
of the P-N junction. When the potential across Cl reaches the
"breakdown" value the forward resistance of the unijunction
transistor junction reduces to a very low value and discharges
the capacitor. The capacitor then charges again and the cycle
is repeated. The oscillator stage is temperature and voltage
stabilized by the setting of R3. At a given ambient tempera-
ture,. and at a specific supply voltage, varying R3 will not
cause a large change in frequency but the setting of R3 must
not be altered since it has been set to stabilize the oscine-
tor over the temperature and voltage range
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V. MAINTENANCE
Since the accuracy of the oscillator depends upon the unijunction
transistor and the setting of R3, the most difficult repair prOblem
is the replacement of the unijunction transistor. Replacement of
' the unijunction transistor must be accompanied by a resetting of
R3. This is done in the following manner:
a. Remove the internal battery and connect a variable voltage.
supply to the proper terminals of the REMOTE socket (see
3.2.2.). This supply should have a continuously variable
voltage range of at least 15 to 30 volts.
b. Connect the OUTPUT to the Y-axis of an oscilloscope and an
audio signal generator to the X-axis of the oscilloscope.
c. Adjust the frequency of the audio signal generator to that
of the reference oscillator.
d. Set R3 to minimum resistance.
e. Vary the applied voltage from 15 to 30 volts and note how
much change occurs in the frequency of the reference oscil-
lator'. If the frequency changes more than one or two cycles
per second. R3 should be increased slightly and the voltage
changed from 15 to 30 volts again. Find the value of R3
which maintains the frequency of the oscillator essentially
constant with changes in supply voltage. In some cases it
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may be found that the value of R3 for minimum frequency
change may be zero but there should never be a case where
the required resistance is greater than 500 ohms, the maxi-
mum value of the potentiometer.
The only maintenance required in the field is the periodic replace-
ment Of the battery.
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Li
Component
? COMPONENT LIST
Value or Tat
Manufacturer
B.
Battery
22.5 volt
Eveready 412E or
Burgess U15
Cl
Capacitor
.01 uf silver mica, Type MS-11
Sprague
C2
1.2 uf, 30V DC, tantalum
Type STA 170
Fansteel
R1
Resistor
*91,000 ohm, 5% 1 watt
Allen-Bradley
R2U
10,000 ohm, variable wire-
wound, Model 300-00
Daystrom-Pacific
R3 ,
500 ohm, variable wire-wound
Model 300-00
Daystrom-Pacific
R4
n
Variable composition with
switch, Model 1 Radiohm
Centralab
801
Socket
Connector) coaxial
IPC 46025
SO2
Connector, type 4-20S
Continental
SW1
Switch
Push button, SPST, Series 30
Grayhill
SW2
Ti
T,
Transformer
SPST ganged with R4
boo ohm to 3.2 ohm
um Dot 4
Thi
Transistor
Unijunction 43X5A513 743
(ZJ14)
G.E.
TR2
t!
?NPN, type 2N35
Sylvania
* This is nominal value and may vary between units.
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