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MODEL 920
STANDARD DEVIATION
METER
I N S T R U C T I O N MANUAL
AUTOMATED INDUSTRIAL ELECTRONICS CORP.
MEASUREMENTS
BATESBURG SOUTH CAROLINA
N O PART O F THIS MANUAL MAY BE
REPRODUCED I N WHOLE OR IN PART
EXCEPT BY PERMISSION OF
MEAS URE ME NTS
MODEL 9 2 0
STANDARD DEVIATION METER
OPERATING INSTRUCTIONS
COPYRIGHT 197 0 BY MEASUREMENTS
P r i n t e d i n U. S oA.
AUTOMATED INDUSTRIAL ELECTRONICS CORP.
MEASUREMENTS DIVISION
Batesburg, S. C. 29006 ( 8 0 3 ) 532-9256
TABLE OF CONTENTS
PAGE
Foreword
Front View of Model 9 2 0
Block Diagram
Section I INTRODUCTION
A. Scope of manual
Section I1 DESCRIPTION AND DATA
A. General
B. Technical C h a r a c t e r i s t i c s
C. DesignFeatures
D. Components Supplied
E. Packaging
Section 1 1
1 CONTROL FUNCTIONS
A. Power
B. Input Gain Control
C. Local Oscillator Tuning
Dm FineTuning
E. Meter Range Switch
F. Audio Spkr
G. Audio Level
H. Scope
I. + Deviation -
Section IV POWER SUPPLY
A. Battery Operation
B. A. C. Operation
C. Battery Recharging Procedure
Section V OPERATION
A. Deviation Measurements
B. Distortion Measurements
C. N o i s e Measurements
Section VI MAINTENANCE
A. General Precautions
B. Battery Installation
C. Removing t h e Instrument from the C a s e
Dm Distortion Adjust
PAGE
E. Filter Termination Adjust
F. DividerAdjust
G. Meter Adjust
H. Discriminator Adjust
I. Power Overloads (Mixer CR4) Replacement
Section VII STORAGE AND SHIPMENT
A. Storage
B. Shipment
Section VIII TABLE OF REPLACEABLE PARTS
Section IX PRINTED CIRCUIT BOARD PARTS LAYOUT
A. Local Oscillator Board
B. I. F. Board
C. Pulse Network Board
D. Audio Board
Em Filter and Power Supply Board
APPENDIX I SCHEMATIC DIAGRAM
FOREWORD
Additional information with regard t o the applications and
maintenance of t h i s equipment w i l l be a v a i l a b l e from time t o time.
Users of the Model 9 2 0 Standard Deviation Meter a r e urged t o d i s c u s s
their problems with us and t o s u g g e s t s u c h modifications a s might make
the instrument more adaptable t o t h e i r s p e c i a l requirements.
Whenever p o s s i b l e , maintenance difficulties should b e re-
ported t o MEASUREMENTS before proceeding with the a c t u a l repairs.
Through our familiarity with the instrument, w e a r e i n a position t o
s u g g e s t the most expedient and accurate repair procedure.
Your Model 9 2 0 Standard Deviation Meter h a s been designed
and manufactured t o t h e highest standards of instrument quality. With
reasonable c a r e , many years of trouble-free s e r v i c e c a n b e expected
of it.
Engineering Department
MEASURE MENTS
AUTOMATED INDUSTRIAL ELECTRONICS CORP.
10 Granite Street
Batesburg, S. C. 29006
Figure 1 Front View of t h e Model 920 Standard Deviation Meter
.
SECTION I
INTRODUCTION
A. SCOPE O MANUAL
F
a. This manual describes the operation o the Model 920 Standard
f
Deviation Meter for measuring peak deviation of F. M. transmitters. To
insure optimum performance, instructions for field maintenance are included,
along with a list of replaceable parts.
SECTION I1
DESCRIPTION AND DATA
A. GENERAL
a. The Model 9 2 0 Deviation Meter is designed to accurately
measure the peak frequency deviation of frequency modulated communication
transmitters.
The Model 9 2 0 contains an accurate, linear, counter-type dis-
criminator and a reliable peak reading voltmeter.
The highly stable conversion oscillator allows measurement a t
frequencies from 2 5 to 1000 MHz with low inherent residual frequency modu-
lation and maximum freedom from drift. To extend the useful range of the
instrument below 2 5 MHz, an external oscillator may be used to heterodyne
transmitter frequencies to the 100 kHz intermediate frequency.
A discriminator output is available from the two front panel
jacks labeled SCOPE and SPKR. The output from the SPKR. jack includes
a 750 micro-second de-emphasis network which allows the Model 9 2 0
Deviation Meter to be used as a standard receiver meeting the requirements
of EIA Standard RS-152-A. Considerable care was taken in the manufacture
of the Model 92 0 to insure low inherent noise and distortion compatible with
the EIA Standard. The SPKR. jack provides a convenient source for measure-
ments of distortion and noise, or it may be used to drive the 8 ohm speaker
provided in the front panel cover.
The SCOPE output jack provides a linear output from the dis-
criminator, and theref ore noise and distortion measurements may be made
without the de-emphasis network.
The output of both the SPKR jack and the SCOPE jack may b e
viewed on an oscilloscope.
TECHNICAL CHARACTERISTICS
a. Carrier Frequency Range: 25-1000 MHz (25-50 MHz l o c a l
oscillator provides useful harmonics t o 100 0 MHz. )
be Sensitivity: 25 millivolts a t frequencies t o 500 MHz; 50
millivolts t o frequencies of 1000 MHz.
c. Residual Frequency Modulation: L e s s than 100 Hz a t 500 MHz.
d. Input Impedance: Nominally 50 ohms.
e. geviation Ranges: 0 to 2 k H z , 0 to 5 k z z , 1 to 2 0 kHz.
2
f. Deviation Accuracy: *306 of full s c a l e .
g. Modulation frequency Response: Flat f r o c Hz t o 8 kHz.
h. Input Gain Control: L i ~ e a taper potentiometer provides 26 db
r
of attenuation.
i. Maximum Power Input: 2 00 milliwatt s.
j. Speaker Output: Provides a 75 0 micro-s econd de-emphasis
network. This jack may b e used t o drive t h e 8 ohm s p e a k e r provided i n
the front cover. The l e v e l of de-emphasized audio output may b e adjusted
with t h e AUDIO LEVEL control.
k. SCOPE Output: Provides a l i n e a r audio output from a n emitter
follower.
1. Power Supply: A well-regulated power supply operates off a
115 volt 50-60 Hz line. Provision is a l s o made f o r battery operation.
Three Eveready rechargeable batteries #563 or their equivalent may be used.
Nine "D" s i z e cells may a l s o b e used. Maximum power consumption is 3
watts.
Ce DESIGN FEATURES
a. The Model 920 Standard Deviation Meter is a completely s e l f -
contained solid s t a t e unit which is portable, a c c u r a t e , and simple t o operate.
b. Measurements a r e e a s i l y read on a large, linear, taught-
band panel meter.
c. An extremely s t a b l e local oscillator provides useful harmonics
up t o 1000 MHz. This oscill~i::,.r completely shielded t o minimize resi-
is
dual noise.
d. For maximum portability the Model 920 may be powered from
batteries, (nominally 13. 5 volts) or from a 115 volt 50-60 Hz power line.
e. When the Model 92 0 Standard Deviation Meter is operated
from t h e AC powzr line, a well-regulated and well-filtered D. C. power
supply provides good stability and low residual hum and noise.
f. A charging circuit is provided t o recharge rechargeable batteries
up t o t h e i r nominal voltage.
g. Three deviation ranges from 0 t o 2 kHz, 0 t o 6 kHz, and 0 t o
20 kHz a r e provided.
h. SPKR Output is provided along with a n 8 ohm s p e a k e r mounted
in t h e front cover. The s p e a k e r output includes a 750 micro-second de-
emphasis network, and a level control.
i, SCOPE Output is available from a front panel jack. This
output is linear and may be viewed on a n oscilloscope,
j. A deviation (+) (-) switch allows t h e measurement of peak
deviation on both s i d e s of t h e carrier.
D. COMPONENTS SUPPLIED
a, The following is included with e a c h shipment:
1 Model 92 0 Standard Deviation Meter
Approx. Weight (less batteries) 10 lbs.
Height 9"
Width 7"
Depth 8-1/2"
Volume .
3 cu. ft.
1 Cover with speaker
1 Power Cord
1 Manual of Operating and Maintenance Instructions
1 Antenna
Em PACKAGING
Domes tic Export
Approx. Weight ( l e s s b a t t e r i e s ) 13 lbs. 2 5 lbs.
Length 13" 2 1"
Width 10" 13"
Depth 12" 16"
Volume .9 cu-ft. 2.5 cu. ft.
For export t h e Model 920 is p a c k e d i n a wooden s h i p p i n g container.
SECTION 1 1
1
CONTROL FUNCTIONS
A. POWER
a. The t h r e e position POWER SELECT s w i t c h l o c a t e d on t h e b a c k
of t h e 92 0 s e l e c t s e i t h e r AC Line Operation, Battery Operation o r Battery
Charge position.
b. The ON-OFF s w i t c h o n t h e front p a n e l controls t h e a p p l i c a t i o n
of b i a s v o l t a g e t o t h e c i r c u i t s of t h e Model 920.
c. The f u s e s l o c a t e d i n t h e b a c k of t h e instrument protect a g a i n s t
overload.
Be INPUTGAINCONTROL
a. This is a l i n e a r potentiometer w h i c h a d j u s t s t h e g a i n of t h e
s i g n a l applied t o t h e metering c i r c u i t s . Approximately 2 6 db attenuation
is possible.
C. LOCAL OSCILLATOR TUNING
a. This d i a l controls t h e tuning of t h e l o c a l o s c i l l a t o r which
o p e r a t e s between 25-50 MHz. The l o c a l o s c i l l a t o r h a s u s e f u l harmonics
t o 1000 MHz a n d is mixed with t h e incoming s i g n a l t o produce t h e 100
kHz intermediate frequency.
D. FINE TUNING
a. This control permits extremely fine electronic adjustment of
the l o c a l oscillator frelquency t a i;l_icilitate tuning.
E. METER RANGE SWITCH
a. This switch s e l e c t s t h e meter function a s described i n the
following:
1. BAT: I n t h i s position the meter c h e c k s t h e D. C. supply
voltage n e c e s s a r y for accurate operation. If t h e POWER SELECT switch
SW3 is in t h e A. C. position t h e meter i n d i c a t e s t h e rectified and filtered
A.C. voltage. This reading should be somewhere in t h e portion of the
meter marked BAT.
If t h e POWER SELECT switch is in t h e BAT position, the
meter indicates the b a t t e r ~ rvoltage. The battery voltage should indicate
three quarter s c a l e or greater. A line indicating minimum battery voltage
is marked on t h e meter s c a l e . If the battery voltage is low, the batteries
should be recharged a s per instructions Section I V Paragraph C.
NOTE: Do not attempt t o recharge non-rechargeable batteries.
2. TUNE: In t h i s position the meter w i l l peak when the
l o c a l oscillator is adjusted t o produce a 100 kHz b e a t with t h e incoming
signal.
3. 2 0 k H z , 6 kHz, or 2 kHz; t h e s e positions s e l e c t the
d e s ired meter deviation range.
4. CAL 1: This position is used only when checking t h e
discriminator.
5. CAL 2: This position is u s e d t o check t h e gain of t h e
audio amplifier.
F. AUDIO SPKR: This front panel jack provides a low impedance output
for s p e a k e r connections. This output circuit contains a 750 micro-second
de-emphasis network.
G. AUDIO LEVEL: Controls the output level from the SPKR jack.
H. SCOPE: A front panel jack which provides a linear audio output.
I. + DEVIATION - : This switch allows t h e measurement of deviation
on both s i d e s of the carrier.
SECTION IV
POWER SUPPLY
A. BATTERY OPERATION
a. The Model 920 may be used with three $563, 4 . 5 volt recharge-
a b l e Eveready batteries o r t h e i r equivalent, or with nine standard " D" c e l l s .
The following procedure should be followed t o battery operate
the Model 92 0:
1. Disconnect t h e A. C. power cord.
2. Slide the power s e l e c t switch on the back of t h e
instrument t o the BAT position.
3. Rotate the METER RANGE switch SW1 on the front panel
t o BAT. If t h e meter reads above the three quarter s c a l e a s indicated by
the BAT marking on t h e meter, then there is sufficient battery voltage for
accurate operation.
4. If t h e meter reads below the BAT mark then the batteries
should be replaced or recharged t o insure accurate operation.
B* A C . OPERATION
.
a. The Model 920 may be operated from a 115 volt 50-60 Hz
source of line voltage a s follows:
1. Connect t h e line cord provided with t h e Model 9 2 0
between t h e connector on t h e back of t h e c a s e and t h e A. C. plug.
2. Slide the POWER SELECT switch SW3 located on t h e
back of t h e c a s e t o t h e A. C. position. The instrument is now ready f o r
operation.
C. BATTERY RECHARGING PROCEDURE
CAUTION
Do not attempt t o recharge non-rechargeable batteries.
a. TheModel920hasabuilt-inchargingcircuitformaximum
convenience i n recharging run down batteries.
If t h e B T check position i n d i c a t e s t h a t the battery voltage is
A
low connect the Model 920 t o the A. C. power l i n e and switch t h e POWER
SELECT switch SW3 on t h e back of t h e instrument t o the CHARGE position.
The batteries a r e now being charged. It is not n e c e s s a r y t o have t h e front
panel POWER switch i n t h e ON position t o charge batteries.
A full s c a l e meter reading i n t h e BAT check position indicates
t h a t t h e batteries a r e charged t o t h e i r nominal voltage of 13.5 volts. This
is t h e i d e a l maximum voltage t o which t h e batteries should be charged.
An overnight charge is recommended. However, a longer
charge w i l l not harm t h e instrument although t h e useful battery life may b e
shortened. The a c t u a l number of hours n e c e s s a r y t o recharge t h e batteries
is dependent on t h e battery voltage a t t h e s t a r t of t h e charge and t h e num-
ber of times t h a t the batteries have b e e n recharged previously.
SECTION V
OPERATION
A. DEVIATION MEASUREMENTS
The following procedures a r e i d e n t i c a l f o r either battery or A. C.
operation.
NOTE: When f i r s t making deviation readings where s i g n a l
strength is unknown, it is b e s t t o l o o s e l y couple t o the trans-
mitter under t e s t o r t o u s e a n e x t e r n a l attenuator. This proce-
dure protects t h e mixer diode CR4 from overloads.
a. Place the METER RANGE switch i n the TUNE position and
rotate t h e LOCAL OSCILLATOR TUNING t o obtain a peak meter reading.
This w i l l be obtained whenever t h e l o c a l oscillator (fundamental or
harmonic frequency) is e x a c t l y 100 kHz away from the input frequency.
When the transmitter frequency is between 25 and 50 MHz, t h e fundamental
frequency of the l o c a l o s c i l l a t o r is used. When the transmitter is above
50 MHz, harmonics of t h e l o c a l oscillator will produce the desired 100 kHz
difference frequency. The following chart lists d i a l readings t h a t may be
u s e d a t various mobile transmitter frequencies.
Mobile Trans mitter Model 920 Harmonic
Frequency (MHz) (*lo0 kHz)
Fundamental
2 nd
b. Adjust INPUT m I N t o bring meter pointer within blue area of
the scale. If n e c e s s a r y , reduce coupling t o t h e transmitter under t e s t , o r
u s e a n external attenuator t o allow peaking in t h e blue area.
NOTE: When using harmonics of t h e l o c a l oscillator, always
u s e t h e highest frequency s e t t i n g of the d i a l (lowest harmonic) for
maximum sensitivity.
c. Place METER RANGE switch i n either 20 kHz, 6 kHz, or 2 kHz
position and read deviation directly o n meter s c a l e . If the l o c a l oscillator
frequency is below t h e s i g n a l frequency, t h e meter w i l l indicate deviation
on t h e high s i d e of carrier, when the (+) (-) switch is i n (+) position. (Peak
deviation is equal t o one half t h e sum of t h e (+) a n d (-) deviation readings.)
Unequal positive and negative readings indicate modulation asymmetry.
DISTORTION MEASURE ME NTS
a. Tune t h e Model 92 0 t o t h e transmitter s i g n a l a s described i n
SECTION V, Paragraph A, then connect a s u i t a b l e distortion meter t o t h e
SCOPE jack.
Inherent distortion i n the Model 920 is normally l e s s t h a n one
percent of t h e 1 0 kHz deviation level.
Co NOISEMEASUREMENTS
a, Residual carrier noise may b e measured by connecting a high
impedance audio frequency voltmeter t o the SCOPE jack. The inherent
n o i s e of t h e Model 92 0 is approximately -45 d b a t 150 MHz, standardized
a t 1 0 kHz deviation, and a t 1 kHz modulating frequency.
NOTE: Both distortion and noise measurement may be made
a t t h e SPKR jack if it is desired t o make t h e measurements through
a 750 micro-second de-emphasis network. In t h i s c a s e t h e audio
l e v e l control should not be turned up s o high t h a t clipping t a k e s
place.
SECTION VI
MAINTENANCE
A. GENERAL PRECAUTIONS
a, The purpose of t h i s s e c t i o n is t o acquaint operating and main-
t e n a n c e personnel with procedures f o r makinq certain adjustments t h a t may
b e n e c e s s a r y after c r i t i c a l parts a r e replaced.
be It should be noted t h a t most of t h e field replaceable parts a r e
available from MEASUREMENTS. Pleas e refer t o MEAS UREMENT's part
numbers when ordering. The adjustment procedures outlined i n t h i s s e c t i o n
should be carefully followed. When the described t e s t equipment is not
a v a i l a b l e , it would be a d v i s a b l e t o return t h e Model 92 0 t o MEASUREMENTS
for repair.
B. BATTERYINSTALLATION
a. Remove t h e four s c r e w s from t h e s i d e s of t h e back portion of
t h e c a s e . These screws are located, one o n e a c h s i d e , approximately
2-1/2" i n from the back of t h e instrument.
b. Remove t h e back portion of t h e instrument and disconnect the
power connector.
c. Remove the battery hold down s t r a p mounted with four s c r e w s
t o t h e bottom and s i d e of t h e back of the c a s e .
d. Install batteries being s u r e t o observe polarity a s indicated
by the markings on t h e battery holder.
e. Reassemble the back cover of t h e instrument.
C. REMOVING THE INSTRUMENT FROM THE CASE
a. Disconnect t h e power cord from t h e r e a r of the c a s e and lift
the front cover from t h e hinges.
b. Lay t h e instrument on its back and remove the four s c r e w s
located on t h e center lines and n e a r e s t t h e outside e d g e of t h e front panel.
c. Lift t h e instrument out of its c a s e being careful not t o h i t the
function switch or any of t h e printed circuit boards.
DISTORT1ON ADJUST
a. Remove t h e instrument from its case.
b. Connect a n audio o s c i l l a t o r s e t a t approximately 1 kHz t o
the single terminal cinch s t r i p located o n t h e back c h a s s i s of t h e Model
920.
c. Switch t h e METER RANGE switch t o t h e CAL 2 position.
d m Adjust the audio o s c i l l a t o r output for a full s c a l e reading on
the Model 920.
em Connect SCOPE output of t h e Model 9 2 0 t o the input of a dis-
tortion analyzer and a d j u s t R100 for minimum distortion.
FILTER TERMINATION ADJUST
a. Connect a n audio oscillator t o the s i n g l e terminal cinch s t r i p
located on t h e back c h a s s i s .
b. Monitor t h e output of the audio o s c i l l a t o r with a n o s c i l l o s c o p e
or VTVM.
c. Set the audio o s c i l l a t o r a t 400 Hz and a d j u s t t h e output voltage
for a f u l l s c a l e reading on MI.
d. Keeping t h e audio oscillator output c o n s t a n t s e t t h e audio
frequency t o 6 kHz and a d j u s t R13 6 f o r a full s c a l e reading on ~ 1 .
e. Repeat procedures c and d until t h e s a m e reading c a n be ob-
tained on M1 a t both frequencies.
F. DIVIDERADJUST
a. Connect a n audio oscillator s e t a t approximately 1000 Hz t o
the wiper of deck E on SW1. (Deck E is located farthest from t h e front
panel. )
b. Switch t h e METER RANGE s w i t c h t o t h e 20 kHz position.
c. Connect a n o s c i l l o s c o p e or VTVM t o the junction of R8 0 and
R82 i s one tenth t h e voltage a s measured a t t h e output of t h e audio oscil-
lator.
Go METER ADJUST
a. Switch t h e METER RANGE switch t o t h e CAL 2 position.
b. Connect a n audio o s c i l l a t o r s e t a t approximately 1000 Hz t o
the s i n g l e terminal cinch s t r i p located o n t h e back of t h e mounting c h a s s i s .
c. Set the output of t h e audio generator t o 4 volts "peak-to-peak".
d. Adjust meter a d j u s t potentiometer R96 for full s c a l e deflection
a s viewed on meter M1.
He DISCRIMINATOR ADJUST
a. Connect a 1 0 0 kHz k1% o s c i l l a t o r to the input connector of
the Model 920.
b. Place METER RANGE switch i n the TUNE position, and a d j u s t
the s i g n a l strength t o bring the meter pointer t o t h e blue a r e a of the s c a l e .
c. Place METER RANGE switch in CAL 1 position. The meter
should indicate full s c a l e deflection. If n e c e s s a r y a d j u s t R73 t o bring
the meter reading t o full scale.
NOTE: The above adjustments "E" through "H"may effect
e a c h other and should be double checked for a n y slight read-
justments t h a t a r e necessary.
I. POWER OVERLOADS (MIXER DIODE CR4) REPLACEMENT
If t h e input t o t h e Model 92 0 e x c e e d s approximately 2 00 milliwatts ,
there is danger that mixer diode CR4 may b e damaged.
Mixer diode CR4 may be replaced a s follows:
1. Remove t h e instrument from its c a s e .
2. Remove t h e p u l s e network printed circuit board mounted
on the right s i d e of t h e Model 920 from its connector.
3. Remove the four s c r e w s holding t h e s h i e l d p h t e of the
l o c a l oscillator board which is mounted underneath t h e pulse network
board.
4. Refer t o t h e printed circuit board layout of the l o c a l
oscillator board and remove mixer diode CR4 from t h e diode " s n a p c l i p s ".
5. "Snap in" t h e replacement diode being s u r e to observe
the correct polahty.
6. Reassemble the Model 920.
SECTION VII
STORAGE AND SHIPMENT
A. STORAGE
a. Remove d u s t from controls and outer surface of instrument with
a c l e a n rag.
b. Wrap instrument in heavy wrapping paper and s e a l s e a m s with
gummed tape or similar adhesive.
c. Store i n a dry place. If e x c e s s i v e humidity is unavoidable, t h e
wrapped instrument should be placed i n a moisture-proof bag with a sufficient
quantity of drying agent, such a s s i l i c a g e l , t o insure a dry atmosphere. When
the u s e of bag and desiccant is necessary, t h e instrument should be checked
a t six-month intervals t o determine t h e effectiveness of t h e s e a l .
B e SHIPMENT
a. Wrap the instrument with heavy wrapping paper and s e a l seams
with gummed tape or similar adhesive.
b. Place in fibre-board carton or wooden box large enough t o permit
a t l e a s t three inches of excelsior or similar packing material between the
instrument and s i d e s of t h e box. For export packing t h e instrument must be
wrapped i n water-proof paper and the s e a m s s e a l e d with waterproof glue o r
similar sealing compound before being placed in a wooden box.
SECTION VIII
TABLE OF REPLACEABLE PARTS
M o d e l 92 0 Standard Deviation M e t e r
Meas.
Symbol Part No. Des cription
Capacitors
C e r a m i c Feed-thru 1 K m m f GMV
I1 I1 II 11 II
II
Tubular 5 mrnf * l o %
II It
15 "11
It Disc . 0 0 1 mf 11
Variable; Air D i e l e c t r i c 2 s e c t i o n s
Mica 2 2 0 mmf & l o % lOOV
C e r a m i c Tubular 5 mmf*10%
11
Feedthru 55 mmf
II Disc . 001 mf *lo%
Mylar
Electrolytic
Mylar
I1
Electrolytic
Mylar
11
Electrolytic
Mylar
I1
Electrolytic
Mylar
I1
Electrolytic 1 0 mf 25v
Mylar . 1 mf *20%
Mica 68 mmf *lo% 100V
Mica
II
Model 92 0 Standard Deviation Meter
Meas.
Symbol P a r t No. Description
Electrolytic 5 0 mf 15V
Mica 47 mmf
Mylar . 2 2 mf &20%
Ceramic Tubular 1 0 mmf 510%
Electrolytic 5 0 mf 15V
Mylar 2 2 mf *20%
Mica 150mmf & l o % 100V
Electrolytic 5 0 mf 15V
Electrolytic 1 0 mf 2 5V
Ceramic 6 8 mmf * l o % NPO
Electrolytic 2 5 0 mf 12v
If
5 0 mf 12v
Ceramic Disc 2.2Kmmf GMV
Electrolytic 50 m f 12v
Ceramic Disc 2.2Kmmf GMV
Electrolytic 1 0 0 mf 12v
It
5 0 mf 12v
Ceramic Disc 2.2Kmmf GMV
Electrolytic 2 5 mf 25V
Mylar . 1 mf *20%
II I1 It II
Ceramic Disc 1 5 mmf 5 1 0 %
Electrolytic 2 mf
Ceramic Disc 470mmf & l o %
Electrolytic 2 5 mf
Mylar 1 mf *20%
Electrolytic 2 5 mf
Electrolytic
II
Ceramic Disc
It 11
Mylar
Electrolytic
Mylar
II
>
II
Model 920 Standard Deviation Meter
Meas.
Symbol Part No. Description
Mylar
Mica
Mylar
11
Diode
II
II
I1
Rectifier
11
Diode
11
Diode
11
Diode
Diode
II
Fuses
MDV 1/8 amp. s l o blow
AGC 1/2 amp.
Connectors
Connector
Socket
Jack Scope
Jack Speaker
Coils
R o F Oscillator c o i l
o
Model 92 0 Standard Deviation Meter
Meas.
Symbol Part No. Description
R. Fe Choke
II II
Filter Coil
Variable Inductor
Meter
Meter & Bezel
Receptacles
Plug
11
Part of W1
II II
Transistors
Model 92 0 Standard Deviation Meter
Meas.
Symbol Part No. Des cription
Switches
Meter Range
Deviation
Power S e l e c t
Power
Transformer
Transformer
Cord; Power, includes P6 & P7
Resistors
Fixed Comp. 150 K
11 I1
47 K
18 K
Variable 10 K
Fixed Comp. 4. 7 K
11 11
100 ohms
II II
82 K
470 ohms
68 "
51 "
510 "
Fixed Comp. 33 K
11 I1
2.2 K
5.6 K
330 ohms
1K
100 ohms
33 K
5. 6 K
2.2 K
330 ohms
33 K
M o d e l 9%0 S t a n d a r d D e v i a t i o n M e t e r
Meas.
Symbol Part No. Description
Fixed Comp. 5.6 K
I1
I(
100 ohms
I1 II
2.2 K
II
II
33 K
3 3 0 ohms
5. 6 K
2.2K
3 3 0 ohms
100 "
33 K
6.2 K
1.2 K
1 5 0 ohms
1K
33 K
6.2 K
1.2 K
1 0 0 ohms
II I1
It It 6.8 K 11 tI
II 11 3.3 K 11 II
I1 11 2.2 K I1 11
I1 11
22 K II II
If I# 3 3 ohms " In
I1 I1
680 " 11 11
I1 11
15 K 11
11
I1
68 0 ohms
II
22 K
11
15 K
11
2.2 K
II
1 5 0 ohms
11
1K
11
47 K
I1
27 K
I
I
47 K
I1
1 0 0 ohms
II
1K
11
18 K
I
I
1K
Variable Comp. 1 0 0 ohms
Model 92 0 Standard Deviation Meter
-
.
Meas.
Symbol P a r t Yo. Description
Fixed Comp. 560 ohms *lo% 1 / 4 ~
11 11 150 " 11 I1
Fixed Comp. 900 ohms *
1% 1 / 2 ~
It 11
666 " 81 11
II I1 111 " I1 I1
11 11
500 " II It
II II
30 K & 5% 1/4w
Variable " 10 K *20% 1/2w
11 11 II II
1K
90 Variable Comp. 5 K &20%
91 Fixed I I 33 K &lo%
92 I1 II
680 ohms "
93 7.5 K 5%
94 82 ohms *lo%
95 33 K It
96 Variable " 250 ohms *20%
97 Fixed " 7.5 K f 5%
98 It II
430 ohms "
99 68 " *lo%
RlOO Variable " 25 K *2 0%
101 Fixed I1
470 ohms *lo%
102 II I1
22 K II
103 6.8 K II
104 82 ohms "
105 680 " II
106 68 " 11
107 390 " 11
108 10 K 11
109 75 K II
110 100 K 11
111 1.2 K 11
112 1 0 ohms "
II 11 150hms " 2W
I# la 39 ohms " 1W
Model 92 0 Standard Deviation Meter
Meas.
Symbol Part
---No. Description
Fixed Comp. 300 ohms
II II
100 "
Variable " 1K
11 I1
1OK
Fixed Comp. 12 K
I1 II
9.1 K
560 ohms
51 "
330 "
15 K
4.3 K
33 K
560 ohms
160 K
MC- 1306P Audio Output Stage
Mis cellaneous
Vernier Drive Knob
Fine Tuning Knob
Audio Level Knob
R.F. Gain Knob
Meter Range Knob
Front Cover A s sy. w / ~ p e a k e r
I. F. P. C. Bd. , ASSY.
Pulse Network P. C. Bd. , Assy.
Audio P. C. Bd. , Assy.
Filter P. C. Bd. , Assy.
Local Osc. , P. C. Bd. , Assy.
Speaker 8 ohms . 2 W
Antenna
L O C A L OSC.
PR. C I R . B O A R D
PU L S E NETWORK
PR. C I R . B O A R D
AUDIO
PR. C I R. B O A R D
FILTER
PR. CIR. BOARD