GE MASTER Progress 4ER42E10-33 User manual

Progress Line
406-470 MHz, RECEIVER MODELS 4ER42E10-33 & 4ER42610-33
5 watts at less than 5% distortion
Ultra-High
Standard Receiver Sensitivity Receiver
-85 dB (adjacent channel, 25 kHz channels)
-100 dB at f20
kHz
f.0005% (-30°C to +60°C)
+.0002% (-30°C to +60°C)
k7.5 kHz
GENERAL @ ELECTRIC
I
SPECIFICATIONS "
FCC Filing Designation
Frequency Range
Audio Output
Sensitivity
12-dB SINAD (EIA Method)
20-dB Quieting Method
Intermodulation (EIA)
Selectivity
EIA Two-Signal Method
20-dB Quieting Method
Spurious Response
First Oscillator Stability
Type ER-42-E Receivers
Type ER-42-G Receivers
Modulation Acceptance
Squelch Sensitivity
Critical Squelch
Standard Receiver 0.2 pV
UHS Receiver 0.15 pV
Maximum Squelch Greater than 20 dB quieting (less than 1.5 pV)
Maximum Frequency Separation 0.4%
Frequency Response +1 and -8 dB of a standard 6-dB per octave de-
/-
emphasis curve from 300 to 3000 Hz (1000-Hz
reference)
*Them specifications are intended primarily for the use of the serviceman. Refer to the appropriate Specification Sheet for the complete rpscifidonr.
i
- - - m

TABLE OF CONTENTS
SPECIFICATIONS ...................................................................... Cover
DESCRIPTION ...................................................................... 1
CIRCUIT ANALYSIS ................................................................... 1
RF Amplifier ................................................................... 1
Helical Resonators ............................................................. 2
1st Oscillator and bIultiplier .................................................. 2
Standard Oscillator/~IultiplierBoard ........................................... 2
................................. Optional Oscillator/RIultiplier Board with ICOhl 2
hlultiplier Board ............................................................... 3
1st Mixer ...................................................................... 3
........................................... High IF Amplifier and Crystal Filter 3
................................. 2nd Oscillator. 2nd Mixer and 1st IF Amplifier 3
...............................................
2nd Lo IF Amplifier and Limiters 3
Discriminator .................................................................. 3
Audio-Noise Amplifier .......................................................... 4
Audio Amplifiers ............................................................... 4
Squelch ....................................................................... 4
...................................................................
Channel Guard 4
MAINTENANCE ......................................................................... 5
Disassembly .................................................................... 5
Alignment Procedure ............................................................ 7
Test Procedures ................................................................ 8
......................................... Audio Power Output and Distortion 8
Usable Sensitivity (12-dB SINAD) .......................................... 8
Rlodulation Acceptance Bandwidth ........................................... 8
Receiver Troubleshooting ....................................................... 9
OUTLINE DIAGRAM .................................................................. 10
SCHEMATIC DIAGRAM
................................................................... 12
PARTS LIST
......................................................................... 11
.................................................................. PRODUCTION CHANGES 15
ILLUSTRATIONS
Figure
1
Figure 2
Figure
3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Block Diagram ............................................................ 1
FET Nomenclat~u-e ......................................................... 2
Removing Top Cover ...................................................... 6
Removing Bottom Cover .................................................... 6
Coaxial Cable and Test Loop ............................................. 7
ICOM Frequency Connection Curve .......................................... 7
Test Setup for 20-Hz Double-Trace Sweep Alignment ......................... 7
Detector Probe for Sweep Alignment ....................................... 7
WARNING
1
No one should be permitted to handle any portion of the equipment that is supplied I
with high voltage; or to connect any external apparatus to the units while the
units are supplied with power
. KEEP AWAY FROM LIVE CIRCUITS .
I

DESCRIPTION
General Electric MASTR Progress Line
Receivers Types ER-42-E
& G are double-con-
version, superheterodyne FM receivers de-
signed for operation fn the 406-420 and 450-
470 megahertz bands. The Type ER-42-E Re-
ceivers contain a standard oscillator with
a frequency stability of *.0005%, while the
Type ER-42-G Receivers contain an Integrated
Circuit Oscillator Module (ICOM) with a fre-
quency stability of f0.0002%. Standard and
ultra-high sensitivity (UHS) versions are
available for both types.
The receivers are of single-unit con-
struction and are completely housed in an
aluminum casting for maximum shielding and
rigidity. The top part of the casting con-
tains the front end through the
1st low IF
amplifier stages. The bottom portion of the
casting contains the audio squelch board and
the optional Channel Guard encoder-decoder
board.
CIRCUIT ANALYSIS
The MASTR Progress Line Receiver is
completely transistorized, using silicon
transistors throughout for added reliability.
Input leads to the receiver are individually
filtered by the 20-pin feed-through by-pass
connector 5443.
A regulated +10 volts is
used for all receiver stages except the
audio PA stage which operates from the 12-
volt system supply.
Centralized metering jack 5442
is pro-
vided for use with General Electric Test
Set Models 4EX3A10 or 4EXBKl1, for ease of
alignment and servicing. The Test Set meters
the oscillator, multiplier, and
limiter
stages as well as the discriminator, and
regulated 10 volts.
RF AMPLIFIER (A410/A411)
RF Amplifier A410/A411 is used only in
ultra-high sensitivity (UHS) receivers and
consists of two tuned helical resonators
and an RF amplifier (Ql)
.
The RF amplifier uses a Field-Effect
Transistor (FET) as the active device.
A
FET may be considered a semiconductor cur-
rent path (or channel) whose resistance
is
varied by a voltage applied between the
"gate" and "source" terminals. Lead ident-
ification for the FET
is shown in Figure 2A.
The FET has voltage-controlled characteris-
tics, and may be compared to a vacuum tube
in operation (see Figure 2B).
L-- 406-4XI NHZ
410 410 YHZ 7 I2 l
IST MIXER
- --
XTAL OR ICON RANGE
450-470 NWZ18.233333 - 19.066 66 NHZ
406-420 YWl- 16.401 I1 - 16.983 333 KHz
\ /
1428iA429
J
- -
CHANNEL GUARD - y
XTAL OR ICOM FREQ . OPER FREO - I2 4 YHZ
1406- 470 MU11 24
Figure 1 - Receiver Block Diagram

LBI-3999 CIRCUIT ANALYSIS
A-FET LEADS I B-TUBE EQUIVALENT 1
RC-1626
MIXER QI
Figure 2 - FET Nomenclature
PLATE
(DRAIN)
RF from the antenna is coupled through
cable W444 to a tap on L410/L412. The tap
is positioned to provide the proper impe-
dance match to the antenna. RF energy
is
coupled to L411/L413 through an opening in
the shield wall, and then to the source
terminal of FET
61.
61 operates as a grounded-gate ampli-
fier. This method of operation provides a
low impedance input to the amplifier. The
amplified output
is taken from the drain
terminal and coupled through a tuned circuit
(C7 and L2/L3) to the input of five helical
resonators.
HELICAL RESONATORS
In receivers without the UHS option,
the front end RF selectivity
is provided
by five tuned helical resonators (L414IL419
through L418/L423). RF cable W441 connects
the RF signal from the antenna to a tap on
L414/L419. The tap is positioned to pro-
vide the proper impedance match to the an-
tenna. The output of L418/L423
is coupled
through capacitor C1 to the
1st mixer
assembly.
1ST OSCILLATOR AND MULTIPLIER
Receiver Models 4ER42E10-33 are equip-
ped with standard Oscillator/Multiplier
Boards A415-A420. Receiver Models
4ER42G10-33 are equipped with Oscillator/
Multiplier Boards which use the Integrated
Circuit Oscillator Module (ICOM)
.
Standard Oscillator/Multiplier Board
(A415
- A4201
The oscillator in the standard Oscilla-
tor/Multiplier Board is a transistorized
Colpitts oscillator. The oscillator crystal
operates in a fundamental mode at a f
re-
quency of approximately 16 to 19 megahertz.
The crystal
is cut to provide temperature
compensation at the high end of the tempera-
ture range and
is thermistor compensated at
low temperatures. This provides instant
warm-up with a frequency stability of
+0.0005% without crystal ovens or warmers.
In single-frequency receivers, a jumper
from
H1 to H2 connects regulated +10 volts
to the crystal circuit. Feedback for the
oscillator
is developed across C47.
In multi-frequency receivers, a diode
is connected in series with the crystal and
up to three additional crystal circuits can
be added. The 10-volt jumper
is removed,
and the proper frequency
is selected by
switching the desired crystal circuit to +10
volts by means of a frequency selector switch
on the control unit. Switching the +10 volts
to the crystal circuit forward biases the
diode in series with the desired crystal,
and the crystal frequency
is applied to the
base of oscillator transistor
61. The os-
cillator output
is coupled through C45 to
the base of
1st Multiplier 62.
The 1st multiplier output is coupled
through T1/T2 to Multiplier Board A413/A414.
T1/T2 is tuned to four times the crystal
frequency. The
1st multiplier stage is
metered at 5442-4 through metering network
C38, CR6, R17 and R18.
Oscillator/Multiplier Board With ICOM
(A432-A43 5)
Oscillator/Multiplier Boards A432-A435
uses ICOM Module Model 4EG26A10.
The ICOM module consists of a crystal-con-
trolled Colpitts oscillator, a voltage regu-
lator, and a buffer output stage. The en-
tire module (including crystal)
is enclosed
in a dust-proof aluminum can, with the ICOM
frequency and the receiver operating fre-
quency printed on the top. Access to the
oscillator trimmer
is obtained by prying off
the plastic GE decal on the top of the can.
The oscillator frequency
is temperature-
compensated at both ends of the temperature
range to provide instant frequency compensa-
tion, with a frequency stability of f0.0002%
without crystal ovens or warmers.
In single-frequency receivers, +10 volts
for operating the ICOM
is obtained by a jump-
er from H1 to H2. With the ICOM operating,
diode CR1
is forward biased and the oscillator
output
is applied to the 1st multiplier Q1.
The 1st multiplier output is coupled
through T1/T2 to multiplier board A413/A414.
T1/T2 is tuned to four times the ICOM fre-
quency. The
1st multiplier stage is metered
at 5442-4 through metering network C4, CR5,
R5 and R6.
In multi-frequency receivers, up to
three additional ICOM modules can be plugged
into the board. The 10-volt jumper
is re-
moved and the proper frequency is selected
by switching the desired ICOM to +10 volts
by means of a frequency selector switch on
the control unit.

CIRCUIT ANALYSIS LBI-3999
All ICOM modules are individually
compensated at the factory, and
cannot be repaired in the field.
Any attempt to remove the
ICOM
MULTIPLIER BOARD (A413/A414)
Following the oscillator board are two
multiplier stages. A413-Q1 operates as a
tripler, and Q2 operates as a doubler. Q2
is metered at 5442-1 across metering resis-
tor R6.
The output of Q2 is coupled through
two helical resonator circuits to the source
terminal of the 1st mixer. The helical res-
onators are tuned to six times the 1st mul-
tiplier output for a total multiplication of
24 times the crystal frequency
.
1ST MIXER (A4121
The 1st Mixer uses a Field-Effect Tran-
sistor (FET) as the active device
(Fig. 2).
The FET mixer has several advantages over a
conventional transistor mixer, including a
high input impedance and an output that is
relatively free of harmonics (low in inter-
modulation products)
.
RF from the helical resonators is ap-
plied to the gate of Q1, and injection volt-
age from the multiplier is applied to the
soul-ce. The mixer output is taken from the
drain with the output tuned to the 12.4 MHz
high
IF frequency.
HI IF AMPLIFIER (A4211 AND CRYSTAL FILTER
(A4227
A series-resonant circuit (A412-L2 and
-C3) couples the mixer output to the emitter
of the high
IF amplifier A421. The transis-
tor is connected as a grounded-base ampli-
fier which provides a low impedance for the
mixer input. The amplifier output is coupled
through transformer T1 to the crystal filter.
Highly-selective crystal filter A422
provides the major selectivity for the re-
ceiver. The output of the filter is coupled
through impedance-matching transformer
A424-T2 to the base of the 2nd mixer.
2ND OSCILLATOR, 2ND MIXER
AND 1ST LO IF
AMPLIFIER (A4241
A424-Q4 operates in a Colpitts oscilla-
tor circuit, with feedback supplied through
C18. The oscillator low-side injection
voltage (11,945 kHz) is applied to the base
of the 2nd mixer.
The High IF signal from the filter and
the injection voltage from the 2nd oscilla-
tor is applied to the base of 2nd mixer Q2.
The 445-kHz mixer output is applied to three
tuned low
IF circuits, L1, L2 and L3. These
tuned circuits are required for shaping the
nose of the
IF waveform, and for rejecting
any undesired output frequencies from the
2nd mixer.
The low
IF signal is applied to the
base of 1st low
IF amplifier Q3. The out-
put of Q3 is R-C coupled to the base of the
2nd low
IF amplifier.
2ND LO IF AMPLIFIER AND LIMITERS (A4261
Additional amplification of the low IF
signal going to the limiter stages is pro-
vided by 2nd low
IF amplifier A426-Q1. This
stage is metered at 5442-2 through
a meter-
ing network consisting of C19, CR3 and R25.
Following the 2nd low
IF amplifier are
three
R-C coupled limiter stages (A426-Q2,
-Q3 and -Q4). The 1st limiter is metered
at 5442-3 through metering network C20, CR4
and R26.
DISCRIMINATOR (A4261
The limiter output is applied to a
Foster-Seely type discriminator, where
diodes CR1 and CR2 rectify the 455-kHz
signal to recover the audio. The discrimi-
nator is metered at 5442-10 through metering
network C16 and R23.
AUDIO - NOISE AMPLIFIER (A4261
The discriminator output is coupled
through a low-pass filter (C16, C18, R21
and R22) to the base of audio-noise ampli-
f ier Q5. The filter removes any 455-kHz
signal remaining in the discriminator output.
Q5 operates as
a emitter-follower to match
the discriminator impedance to the VOLUME
control, SQUELCH control, and Channel Guard
input. The stage also provides power gain.
AUDIO AMPLIFIERS (A426)
Any audio present in the incoming sig-
nal is coupled from the emitter of Q5
through the VOLUME control and a de-emphasis
network to the base of audio amplifier Q6.
The de-emphasis network consists of C22, C23,
R30 and R31.
Audio driver Q7 follows the audio
amp-
lifier. The audio output of 07 is coupled
ihrough transformer T1 to provide phase in-
version for the push-pull audio
PA stage.

LBI-3999 CIRCUIT ANALYSIS
6410 and Q411 operate as a push-pull
Class AB audio PA stage. The PA output
is
coupled through audio transformer T410 to
the loudspeaker. The yellow and white
tertiary windings of T410 supply balanced
feedback to the collector of Q7. The feed-
back winding minimizes distortion and pre-
vents the pick-up of external electrical
noise.
Base bias for the PA stage and the
elimination of crossover distortion
is
controlled by bias adjust potentiometer R43.
The potentiometer
is set at the factory as
shown in STEP
1 of the receiver Test Pro-
cedure.
Do not adjust bias adjust poten-
tiometer R43 unless PA transis-
tors Q410 and Q411 have been
re-
nlaced.
Audio high and low are also present at
centralized metering jack 5442, and can be
used as shown in STEP
1 of the receiver
Test Procedure. The output stage provides
5 watts at less than 5% distortion into a
3.5-ohm load at the receiver output
term-
inals (3.2-ohm load at the Control Unit).
SQUELCH (A426)
Noise f the audio-noise amplifier
operates the squelch circuit. With no
carrier present in the receiver, this noise
is coupled to the base of noise amplifier
Q8 through a high-pass filter which attenu-
ates frequencies below
3 kHz. The filter
consists of C30, C31 and R45, as
well as
C34 and L3 in the collector circuit of Q8.
The gain of Q8
is determined by the Squelch
control, which varies the bias on the base
of Q8. Thermistor RT2 keeps the critical
squelch constant over wide variations in
temperature.
The output of noise amplifier Q8
is
rectified by diodes CR5 and CR6, and filter-
ed by C36 and C37 to produce a negative DC
voltage. This DC voltage
is applied to the
base af DC amplifier Q9, turning
it off.
When turned off, the collector voltage of
Q9 rises to approximately 8 volts, turning
on DC amplifier Q10. When conducting, the
collector voltage of Q10 drops to almost
ground potential, which removes the base
bias to audio amplifier Q6 and audio driver
Q7, turning them off
.
When the receiver is quieted by a
signal (unsquelched), the noise in the
re-
ceiver is reduced, turning DC amplifier
Q9 on and DC amplifier Q10 off. This
allows the audio stages to conduct so that
sound
is heard in the speaker.
Resistor R53 connects from the
emitter
of audio driver Q7 to the emitter of noise
amplifier Q8, providing a hysteresis loop
in the squelch circuit. When a weak signal
opens the squelch, the signal level may be
reduced by 4 to 6 dB without the squelch
closing. This
limits squelch "flutter" or
"picket-fence" operation.
With audio driver Q7 conducting, a
positive voltage through R53 helps to
re-
duce the gain of noise amplifier Q8. This
positive feedback provides a quick, positive
switching action in the squelch circuit.
When the receiver squelches, audio driver Q7
turns off and
its emitter potential drops
to zero. This reduces the DC feedback
through R53 to the
emitter of noise ampli-
fier Q8. Reducing the feedback causes Q8
to conduct harder, turning the audio stages
off quickly.
Keying the transmitter removes the +10
volts from J19, turning off DC amplifier
Q9 and turning on Q10 to mute the receiver.
CHANNEL GUARD (A428/A429)
Channel Guard Board Model 4EK16A10 is
a fully transistorized encoder-decoder for
use in the MASTR Professional Series mobile
and station combinations. The tone freq-
uencies are controlled by plug-in tone net-
works that are made with precision components
for excellent stability and reliability.
The tone frequencies range from 71.9 to
203.5 Hz.
Encoder (A428)
Keying the transmitter removes the re-
ceiver mute +10 volts, and forward biases
feedback control diode CR5, causing
it to
conduct. When conducting, the diode shunts
R39 which reduces the impedance of the
positive feedback loop (R39, R35 and C19).
This provides the necessary gain to the base
of Q5 to permit oscillation.
The encoder tone
is provided by selec-
tive amp-oscillator transistors Q5 and Q6
which oscillate at a frequency determined
by the tone network. Negative feedback
applied through the tone network to the base
of Q5 prevents any gain in the stage except
at the desired encode frequency.
Starting network R45, C21, C22 and CR6
provide an extremely fast starting
time for
the encoder tone. Keying the transmitter
removes the receiver mute +10 volts, causing
a pulse to be applied to the base of Q6 to
quickly start the oscillator. Thermistor-
resistor combination R.32 and RT1 provides
temperature compensation for the oscillator
output. Limiter diodes CR3 and CR4 keep
the tone amplitude constant.
Emitter-follower Q7 follows the oscil-
lator circuit. The encoder tone
is taken
from the
emitter of Q7 and applied to an

CIRCUIT ANALYSIS LBI-3999
active low-pass filter (G101) on the trans-
mitter.
Decoder (A428)
The decoder function is designed to
eliminate all calls that are not tone coded
for the Channel Guard frequency
. As long as
the CHANNEL GUARD-OFF switch on the control
unit
is left in the CHANNEL GUARD position,
all signals are locked out except those from
transmitters that are continuously tone
coded for positive identification by the
receiver.
Placing the CHANNEL GUARD-OFF switch
in the OFF position instantly disables the
Channel Guard operation so that all
calls
on the channel can be heard. When the hook-
switch option
is used, lifting the micro- .
phone from its hanger disables the Channel
Guard Circuit.
Audio, tone and noise
are taken from
the
emitter of the receiver audio-noise
amplifier A426-Q5 and
is fed through A428-
J1 to four tone amplifier and bandpass
filter circuits. The filters remove the
audio and high-frequency noise from the sig-
nal, and the tone amplifiers provide suffici-
ent gain to insure clipping by
limiter diodes
CR1 and CR2. The clipping action eliminates
variation in the squelch performance due to
changes in tone deviation. The signal
is
then applied to selective amplifiers Q5 and
Q6 which amplify only the tone determined by
the tone network.
The output of the selective amplifier
is applied through emitter-follower Q7 to
the high gain, broad-band tone amplifiers
Q8 and 69. The output of Q9
is rectified
by detector diodes CR7 and CR8, and the
re-
sulting negative DC voltage controls the
squelch gate. Q8
is normally biased for low
gain. Then the tone
is detected by CR7 and
CR8, feedback
is provided through R54 to
quickly change the bias on Q8 for full gain.
This ensures
a more positive "unsquelching"
act ion.
Squelch gate diode CR9
is normally
forward biased by
a positive DC voltage
(approximately 1.5 volts) fed through R58.
The forward bias causes CR9 to conduct,
feeding a DC voltage to the base of DC ampli-
fier A426-Q10 in the receiver. This removes
the bias on the receiver audio stages and
holds them off.
When the proper tone
is applied to the
decoder, the negative DC voltage from the
detector diodes back-biases squelch gate
diode CR9 and cuts off the positive bias to
the receiver DC amplifier A426-Q10. However,
the receiver noise squelch circuit continues
to operate until
a carrier quiets the re-
ceiver.
Placing the CHANNEL GUARD
- OFF switch
in the OFF position (or removing the micro-
phone from
its hookswitch) removes the ground
to the base of the decoder DC switch (QlO),
causing it to conduct. This back-biases
squelch control diode CR9 and cuts off the
positive bias to the receiver DC amplifier
(A426-Q10). The receiver noise squelch
circuit continues to operate until a carrier
quiets the receiver.
A tone rejection filter connected in
parallel with A426-52 (in the receiver by-
passes any incoming tone to ground. This
attenuates the tone level reaching the
re-
ceiver audio circuits. The filter is com-
posed of C26, C27, C28, C29, L1 and R59.
An optional tone
reject filter (A429)
that is identical to the filter described
above
is available for use in two-way
radios with transmitter Channel Guard only.
DISASSEMBLY
To service the receiver from the top-
1. Pull locking handle down and pull radio
about one inch out of mounting frame.
(see Fig. 3).
2. Pry up cover at rear of receiver.
3. Slide cover back and lift off.
To service the receiver from the bottom-
1. Pull locking handle down. Pull radio
out of mounting frame
. (see Fig. 4).
2. Remove
screws in bottom cover. Pry up
cover at back of receiver.
3. Slide cover back and lift off .
To remove the receiver from the system
frame-
1. Loosen the two Phillips-head retaining
screws in front casting (see Figure 3).
and pull casting away from system frame
2. Remove the four
screws in the back
cover.
3. Remove the two screws holding the re-
ceiver at each end of the system frame.
4. Disconnect the antenna jack and the 20-
pin connector from the front of the re-
ceiver, and slide the unit out of the
system frame.

MAINTENANCE
Figure
3 - Removing Top Cover Figure 4 - Removing Bottom Cover
BACK COVER
MOUNTING
FRAME
METERING
JACK
RETAINING SCREWS
FOR FRONT CASTING
(1 EACH SIDE)
LOCKING
HANDLE
IF
- AUDIO SQUELCH
DISCRIMINATOR
CHANNEL GUARD
LOCKING HANDLE

EQUIPMENT REQUIRED
COMPLETE RECEIVER ALIGNMENT
1. GE Test Set Models 4EX3A10, 4EX8Kl1, station test meter panel, or 20,000 ohms-per-volt multimeter.
2. A 450 to 460 kHz source (GE Test Set Model 4EX7A10), and 406-470 MHz signal source. Connect a one-inch piece of insulated wire no
larger than .065 inch to generator output probe.
PRELIMINARY CHECKS AND ADJUSTMENTS
1. Connect Test Set toreceiver centralized metering jack 5442, and set meter sensitivity switch to the TEST 1 or 1-volt position.
2. For a large change in frequency or a badly mis-aligned receiver, set crystal trimmer C9 on
1st OSC/MULT board (ER-42-E only) to mid-capacity.
In multi-frequency receivers, set
C10, C11 or C12 to mid-capacity as required.
3. In multi-frequency receivers where the maximum frequency spacing
is less than 500 kHz, align the unit on channel F1. If the frequency
spacing
is greater than 500 kHz, align the receiver on the center frequency.
4. With Test Set in position J, check for regulated +10 volts. If using Multimeter, measure from C425 to C426.
5. If using Multimeter, connect the positive lead to 5442-16 (ground).
6. Disable the Channel Guard.
ALIGNMENT PROCEDURE
OSCILLATOR AND MULTIPLIERS
L5 (1st OSC/MULT) and See Pro- Tune L5 for maximum meter reading. Then tune L1 for minimum meter
1 L1 (2nd MULT) cedure reading.
STEP
Pin 4
1
i ~J~in4
1 5' (MULT L)
TUNING CONTROL READING PROCEDURE
METERING WSITION
L5 (1st OSC/MULT) and
Ll and
L2 (2nd MULT)
1
Sk;u::o--[ Adjust ~4Zora small dip in meter reading.
GE Test Set
or Meter Panel
Maximum Tune L5, L1 and
L2 for maximum meter reading. If two peaks occur '
while tuning L1 and L2, use the peak with the slug nearest the top
of the coil.
Multimeter
- at 5442
Pin 10
Pin 10
DISCRIMINATOR
A
(DISC)
I 1 1 RF SELECTIVITY I
L1 and L2 (on IF-AUDIO
SQUELCH board)
2.
6.
A
(DISC)
I
I I
Insert Generator Probe In: Peak
-
,
the IF-AUDIO & SQUELCH board. Ad-
just L1 (disc primary) 1/2 turn counterclockwise from the bottom of
Next, apply a 455-kHz signal to
52 and 54 and adjust L2 (disc
A
1 pin 10 '
(DISC)
1 1. Hole 411
1 2. Hole 410
See Pro-
cedure
I Pin 2 L3 (1st Mixer)
(2nd
b AMP) ~
C418 thru C417
C415, C416 thru C417
Alternately apply a 450-kHz and 460-kHz signal and check for readings
of at least 0.3 volt, but not more than 0.5 volt on GE Test Set.
Both readings must be within .05 volt. Do not attempt to balance
reading any closer than 0.05 volt.
Zero
7' (2nd :F AMP)
Maximum
I Apply an on-frequency signal in Hole 411 and tune L3 for maximum
i
Pin 2
(2nd IF AMP)
Apply an on-frequency signal into Hole 411. Adjust the signal
generator for discriminator zero.
MaximumPin 2
1 C423 and C424
MaximumC415 thru C418
B
(2nd IF AMP)
C414 thru C418,
L3 (on 1st Mixer)
and C410, C411 and
C7 (on UHS receivers)
Apply an on-frequency signal as above. Tune C423 and C424 for
maximum meter reading, keeping signal below saturation.
meter reading. If two peaks occur, use the peak with the slug near-
est the bottom of the coil.
Apply an on-frequency signal in the Hole shown below, keeping the
signal below saturation. Tune C415 thru C418 for maximum meter
Pin 2
reading as shown below:
I
2ND MIXER & HI IF
I
See Pro-
cedure
The 2nd mixer, and high IF circuits have been aligned at the factory and will normally require no further adjustment. If adjustment
is nec-
essary use the procedure outlined in STEPS
11, 12 and 13.
Apply an on-frequency signal to the receiver antenna jack. Tune
C410, C411 and C7 on UHS receivers for maximum meter reading. On
all receivers, tune C414 for maximum meter reading, and tune C415
thru C418 and
W for maximum quieting.
I T t 1
NOTE
1 L3, L2, L1, T2 (2nd Mixer) 1 Connect scope, signal generator, and detector as shown in Figure 7.
and T1 (Hi IF AMP) 1 Set siensl generator level for 30-50 uu and modulate with 10 kHz at
Refer to
DATAFILE BULLETIN 1000-6 IF Alignment of Two-Way Radio FM Receivers for helpful suggestions on how to determine
when IF alignment
is required.
20 HZ.- wit; detector at the collectoF of Q3 (2nd mixer board out-
put), tune for double trace as shown on scope pattern.
11.
A Pin 10 See Pro- Check to see that discriminator idling voltage in within k.06 volt
(DISC) cedure of zero with no signal applied. Check to see that modulation
acceptance bandwidth is between k7.5 and 9 kHz.
FREQUENCY ADJUSTMENT
14. Refer to the appropriate adjustment procedure for the ICOM or Standard Oscillator.
r
L3 L2, L1, T2 (2nd Mixer)
anA T1 (Hi IF AMP)
B
(2nd IF AMP) Pin 2 Maximum Apply on-frequency, unmodulated signal and tune L3,
L2, L1, T2 (2nd
mixer) and T1 (Hi IF AMP) for maximum meter reading, keeping signal
below saturation.

EQUIPMENT REQUIRED
1. GE Test Set Model 4EX3A10, 4EX8Kll station test meter panel or 20,000
ohms-per-volt multimeter.
C9
F1
ADJ
2. A 406-470 MHz signal source. Connect a one-inch piece of insulated wire no
larger than 0.065 inch to generator output probe.
PRELIMINARY CHECKS AND ADJUSTMENTS
- 58/U CABLE
(TO COUNTER)
1. Connect Test Set to receiver centralized metering jack 5442 and set meter
sensitivity switch to the TEST
1 (or 1-volt position on 4EX8Kll).
2. With Test Set in position J, check for regulated +10 volts. If using Multi-
meter, measure from C425 to C426.
3. If using Multimeter, connect the positive lead to 5442-16 (ground).
4. Disable the Channel Guard
ALIGNMENT PEOCEDURE
L5 (1st OSC/MULT)
and L1 (2nd MULT~
D
(MULT- 1 )
See Pro-
cedure
OSCILLATOR AND MULTIPLIERS
METER
READING
TUNING CONTROL
STEP
Pin 4 Tune L5 for max-
imum meter read-
ing. Then tune
L1 for minimum
meter reading.
PROCEDURE
Figure 5 - Coaxial Cable and Te;
--- --
-
METERING POSITION
L5 (1st OSCIMULT)
and L1 and L2 (2nd
MULT
)
GE Test Set
or Meter Pane
Maximum
Multimeter
- at 5442
Tune L5, L1 and
L2 for maximum
meter reading.
If two peaks
occur while tun-
ing L1 and L2,
use the peak
with the slug
nearest the top
of the coil.
Adjust C423 for
a small dip in
meter reading.
3.
Zcro Apply on on-freq-
uency signal into
Hole 411. Ad,just
the signal gener-
ator for discrim-
inator zero.
Apply an on-freq-
uency signal as
above. Tune C423
and C424 for max-
imum meter read-
ing, keeping
signal below sat-
uration.
G
( MULT- 2 )
Pin 2
___;- (2nd IF AMP) Maximum
I
Pin 4
DEGREES CENT1GRAD1
-
RF SELECTIVITY 1
C423 See Pro-
cedure
-- - ---
Apply an on-freq-
uency signal in
Hole
411 and tune
L3 and C415 thru
C418
for maximum
meter reading,
keeping the sig-
nal below satura-
tion. If two
rl
(2nd IF AMP)
peaks occur when
tuning
L3, use
the peak with the
slug nearest the
bottom
of the
coil.
I3 Pin 2
(2nd
IF AMP)
I
i !
1
Pln 2
C414 thru C418,
L3 (on 1st Mixel')
and C410. C411
a11cl C7 (on LUIS
rec.c~vel.s)
Sc,e Pro-
cc3dul'e
L3, C415-C418
Apply on on-freq-
uetlcy signal to
1 lit, receiver
antenna lack.
Tune C410, C411
and C7 on
UHS
receivers f 01-
maxlmum meter
1-eadin~. On all
recciver5, tune
C414 for
maxlmum
meter 1-eadlng,
and then tune C415
tlil-u C418 and L.?
for maxlrnum qulet-
1ng.
hlaximum
DEGREES FAHRENHEI
-
-
Figure 6 - ICOM Correction C
Rc.1 12~' 1 o t lli' .1l1111'oln'int r. adlust~ncnl])r'oc.ctl~ll.c~ l ur t hc3 ICOhl or Standard

RF AMP 2 1
RG-58/U CABLE SOLDER 8 TAPE
(KEEP LEADS SHORT)
CONNECTOR
(TO COUNTER)
TURNS OF
INSULATED WIRE
RC- 1600
Figure
5 - Coaxial Cable and Test Loop
RF SELECTIVITY
DEGREES CENT1GRADE
5'0 60 70 so sb loo ~io 120
DEGREES FAHRENHEIT RC- 1599
REMOVE
THREE SCREWS
TO SWING
BOARD
UP w
IF-AUDIO & !
DISCRIMIN
52
(HIG
Figure 6 - ICOM Correction Curves

u
zz 5
m rr
m **
1 r. P.
<PV
P. CI CI
JYY
09
* *
*ST
J P. mm m
h
in hY ,, ,, a
rP
-1 -
5Ph
ID J
POO*
CIDJ
ID- (0
50cri
Ym(0
ID 3
Y P
m *ID
Y5
hID w
0 *
PO c PO 1
9 l"
*mar(
0 ric c
ID ID 0 3 1 ri
u00 3
rip.* ID
P CIWID r.r(
J CJ 0
P 0
rio r.~
33 0P. w c+
m **ID
J r. 8
hmOW
5 a0
m- 1
* - - -.
0
Or. 0 Y CIJ
ID PW u w *c
m* ID
0 0 N CI5 ID *
r 50
0 hO41 *
r.m as
JP r-ID
OO c m
ID07
w35r-
5 0 r.09
OY 3 J
0. WID am
p C*

I;-/-
15 ADJ ADJ ADJ ADJ
sst Setup for 20-Hz Double-Trace Sweep Alignment
dix A of
tin 1000-6
uctions
sweep
20 Hz
To Scope
Vertical
IN198
FREQUENCY ADJUSTMENT
LBI-3999
STANDARD OSCILLATOR
Receiver
0 Ext. %Ant 2nd Mixer Bd.
-3~od.
20
Sweep output
Mod.
Hz (Note IL
Detector
Oscilloscope Probe
horizontal
F M
Signal
Generator
Multi-
30-50pv
TUNING I METER
CONTROL
1 READING PROCEDURE
to the antenna jack. Tune
MULT) C9 for zero discriminator
Clo, C11 reading. In multi-frequency
and C12 units, tune C10, C11 or C12
for multi.
frequency
( as required.
I
I -- NOTE -
I
For proper frequency control
of the receiver.
it is re-
commended that all frequency
adjustments he made when the
equipment
is at a tempera-
ture of approximately 75°F.
In no case should frequency
adjustments be made when the
equipment
is outside the
temperature range of 50' to
90°F.
ICOM MODULE
Due to the high stability of the ICOM module,
it is not recommend-
ed that zero discriminator be used as the indication for setting the
oscillator frequency. Instead, measure the ICOM frequency as described in
in the following procedure.
EQUIPMENT REQUIRED:
1. Frequency Counter capable of measuring the 70-80 MHz frequency
range. (The counter should have an accuracy of 0.4 part-per
million.)
2. Coaxial cable with test loop as described in Figure 5.
3. Mercury thermometer.
PROCEDURE:
1. Check the ICOM temperature by taping the mercury thermometer to
the side of the ICOM.
2. Cunnect the lrequency counter to L5 (on the
1st Osc/htult) using
the 4-turn test loop and cable shown in Figure 5.
3. If the ICON temperature
is 80'F (i4"F) or 26.5'C (+2"C). the fre-
quency indication on the counter should be 4 times the frequency
stenciled on the ICOhl case. Ad,just the ICO\l trimmer (if necessary)
to obtain this frequency.
4. If the temperature is not within the 80CF (+4 'F) or 26.5"C (22'C)
range. use the correction curves ot Figure 6 for setting the ICOM
frequency as follows:
a. Check the color dot beneath the GE emblem and select the match-
ing curve to determine the correction factor in parts-per-mll-
lion (PPU).
b. Multiply the frecluency stenciled on the ICOhl by 4 and then
multiply this figure by the correction factor (from Figure 6)
observing the sign (i) given to the correction factor.
c. The frequency measured at L5 should be 4 times the ICON frequen-
cy
i the correction factor. Adjust the ICON trimmer (if re-
quired? to obtain this frequency.
FOR EXAMPLE
-
- 18.233333 hlHz
ICOM Color Dot - Green
Ambient Temperature
- 35°C (95'F)
Correction Factor - -1.15 PPM
(From Figure 6)
blultiply ICOM Frequency by 4;
(18.233333 \Mz
x 4 - 72.933332 hlHz)
Multiply preceding figure by correction iactor:
(72.933 YHz x -1.15 PPM = -83.87 hertz (or -84 hertz)
Set the frequency measured at L5 for 72.933248 MHz;
72.933332 ItHz
- ,000084 \EIz
1 72,933248 illlz
ALIGNMENT PROCEDURE
406-470 MHz MASTR RECEIVER
MODELS 4ER42E10-45
& 4ER42GlO-33
,e 8 - Detector Probe for Sweep Alignment
Issue 2 7

a milliammeter in series
volt lead at P443-11. With
, adjust R43 for a reading
tely 20 milliamps. This
~ouldnot be necessary un-
~t transistor has been re-
iefer to Receiver Trouble-
2edure).
r Alignment (Refer to
~nmenton reverse side of
STEP 2
I SENSITIVITY
#dBSINAD)
F. Leave all controls as they are and all
equipment connected
if the Modulation
Acceptance Bandwidth
test is to be per-
formed.
SERVICE CHECK
If the sensitivity level is more than
rated 12 dB SINAD, check
the alignment of
the RF stages as directed in the Alignment
Procedure, and make
the gain measurements as
shown on the Troubleshooting Procedure.
STEP 3
MODULATION ACCEPTANCE
BANDWITH (IF BANDWITH)
3cks out properly, measure
If STEPS 1 and 2 check out properly,
itivity as follows: measure the bandwidth as follows:
-microvolt, on-f requency
A. Se_t the Signal Generator output
for twice
ated by 1000 Hz with 3.3-kHz the microvolt reading obtained in the
5441. 12-dB SINAD measurement.
NGE switch on the Distortion
the 200 to 2000-Hz distortion
Dn (1000-Hz filter in the
une the
filter for minimum
ull on the lowest possible
30%, etc.)
NGE switch to the SET LEVEL
Lter out of the circuit) and
nput LEVEL control
for a +2
n a mid range (30%).
ng the signal generator out-
the RANGE control from SET
distortion range until a
3nce (+2 dB to -10 dB) is
Neen the SET LEVEL and
ange positions (filter out
2).
fference (Signal plus Noise
In to noise plus distortion
? "usable" sensitivity level.
B. Set the RANGE control on the Distortion
Analyzer in the SET LEVEL position (1000-
Hz filter out of the circuit), and adjust
the input LEVEL control
for a +2 dB read-
ing on the 30% range.
C. While increasing the deviation of the
Signal Generator, switch the RANGE con-
trol from SET LEVEL to distortion range
until a 12-dB difference
is obtained
between the SET LEVEL and distortion range
readings
(from +2 dB to -10 dB).
D. The deviation control reading
for the
12-dB difference
is the Modulation
Acceptance Bandwidth
of the receiver.
If should be more than k7.5 kHz (but
less that k9.5 kHz).
SERVICE CHECK
ity should be less
than rated
specification
with an audio
If the Modulation Acceptance Bandwidth
least 2.5 watts (2.9 volts
test does not indicate the proper width, make
le 3.5-ohm receiver load us- gain measurements as shown on the Receiver
~rtionAnalyzer as a VTVM). Troubleshooting Procedure.

equency
hertz
enna jack
rom 5701-2
or from
he Distor-
e resistor
lookswitch.
zer input
r five-watt
Distortion
: according
Ins. Reading
the receiver
d, leave
s'they are.
an
5%, or
than five
xks:
+--low volt-
[Refer to
)r voltages.)
:n the
.clockwise.
Then connect a milliammeter in
series
with the +12 volt lead at P443-11. With
no signal in, adjust R43 for a reading
of approximately 20 milliamps. This
adjustment should not be necessary un-
less an output transistor has been re-
replaced.
G. Audio Gain (Refer
to Receiver Trouble-
shooting Procedure).
H. Discriminator Alignment (Refer to
Receiver Alignment on reverse side of
page).
STEP 2
USABLE SENSITIVITY
(12-dB SINAD)
F. Leave all
equipment
Acceptance
formed .
If the sex
rated 12 dB SIP
the RF stages a
Procedure, and
shown on the Tr
MODULP
BANDW
If STEP 1 checks out properly, measure If STEPS 1
the receiver sensitivity as follows: measure the banc
A. Apply a 1000-microvolt, on-f requency A. Set the Sig
signal modulated by 1000
Hz with 3.3-kHz the microvc
deviation to
5441. 12-dB SINAI
B. Place the RANGE switch on the Distortion
Analyzer in the 200 to 2000-Hz distortion
range position (1000-Hz filter in the
circuit). Tune the filter for minimum
reading or
null on the lowest possible
scale (loo%, 30%, etc.)
C. Place the RANGE switch to the SET LEVEL
position (filter out of the circuit) and
adjust the input LEVEL control for a
+2
dB reading on a mid range (30%).
D. While reducing
the signal generator aut-
put, switch the RANGE control from SET
LEVEL to the distortion range until a
12-dB difference (+2 dB
to -10 dB) is
obtained between the SET LEVEL and
distortion range positions (filter out
and filter in).
E. The 12-dB difference (Signal plus Noise
and Distortion to noise plus distortion
ratio)
is the "usable" sensitivity level.
The sensitivity should be
less than rated
12 dB SINAD specification with an audio
output of
at least 2.5 watts (2.9 volts
RMS across the 3.5-ohm receiver load us-
ing the Distortion Analyzer
as a VTVM).
B. SettheRAB
Analyzer ir
Hz filter c
the input
I
ing on the
C. While incre
Signal Gene
trol from
I
until a 12-
between the
readings
(f
D. The deviati
12-dB diffe
Acceptance
If should
t
less that 3
If the Mod1
test does not ii
gain measuremen-
Troubleshooting

-J, ------ ---", --...A-YA .A-u -ybLubrlJg aelure starzing witn tne Keceiver 'l'esr; rroce
-
3rly, and low gain. By following the dures, be sure the receiver is tuned and
:nce of test steps starting with Step 1, aligned to the proper operating frequency.
jefect can be quickly localized. Once
TEST PROCEDURE
Measure Audio Power Output as follows:
'EST EQUIPMENT REQUIRED PRELIMINARY ADJUSTMENTS
istortion Analyzer similar to:
'eath IM-12
ignal Generator similar
to:
easurements M-560
-dB attenuation pad, and 3.5-ohm,
0-watt
resistor
% SIGNAL GENERATOR
1. Connect the test equipment to the recei-
ver as shown for.all steps of the
receiver Test Procedure.
2. Turn the SQUELCH control fully clockwise
for all steps of the Test Procedure.
3. Turn on all of the equipment and let it
warm up for 20 minutes.
DISTORTION ANALYZER
A. Apply a 1,000-microvolt, on-frequencj
test signal modulated by 1,000 hertz
with k3.3 kHz deviation to antenna
js
5441.
B. With Five-Watt Speaker:
Disconnect speaker lead pin from 5701
(on rear of Control Unit).
Connect a 3.5-ohm load
resistor from
5442-15 to 5442-7. Connect the Distc
tion Analyzer input across the resisl
as shown.
OR
With Handset:
REMOVE THREE SCREWS AND SWING BOARD OPEN
CONTROL UNIT SPEAKER
REAR
PIN I I
i i
lAl
Lift the handset off of the hookswitc
Connect the Distortion Analyzer input
from 5442-15 to 5442-7.
C. Adjust the VOLUME control for five-wa
output (4.18 VRMS using the Distortio
Analyzer as a VTVM).
D. Make distortion measurements accordin
to manufacturer's instructions. Read
should be
less than 5%. If the recei
sensitivity is to be measured, leave
all controls and equipment as'they ar
SERVICE CHECK
If the distortion is more than 5%, or
maximum audio output is less than fiv
watts, make the following checks:
E. Battery and regulator voltage---low v
age will cause distortion. (Refer to
Receiver Schematic Diagram for voltag
F. P.A. Bias Ad.iust (R43) -- Turn the

STEP 3-VOLTAGE RATIO READ
STEP I-QUICKCHECKS
TEST SET CHECKS
These checks are typical voltage readings measured with GE
Test Set Model 4EX3AlO in the Test
1 position, or Model
4EX8K10 or 11 in the 1-volt position.
C 0.6 VDC
Metering
Position
A
Disc idling
B
2nd IF
I Mul: 2 I 0.3 VDC I
Reading with No
Signal in
Less than
2.05 VDC
.05 VDC
D
Mult 1
Reading with 1 ~v
unmodulated input
I
0.2 VDC
1.0 VDC
SYMPTOM CHECKS
J
Regulated
+10 Volts 10 VDC
SYMPTOM
NO SUPPLY VOLTAGE
Make SIMPLIFIED VTVM GAIN CHECKS from 2nd Mixer through
1st Limiter stages as shown in STEP 2A.
PROCEDURE
I
I--
Check power connections and continuity of supply leads,
and check fuse in power supply. If f~ise
is blown,
check receiver for short circuits.
NO REGULATED 10-VOLTS
LOW 1ST LIM READING
LOW OSCI
LLATORIMULTI- l Check alignment of Oscillator (Refer to Front End
PLIER READINGS Alignment Procedure).
I I
Check the 12-volt supply. Then check regulator cir-
cuit (See Troubleshooting Procedure for Power Supply).
Check supply voltages and then check oscillator reading
at
5442-4 & 5 as shown in STEP 2A.
. Check voltage readings of 1st Oscillator/Multiplier
1
Ql/Q2.
I
I
0 Check antenna connections, cable and relay.
I
LOW RECEIVER SENSITIVITY
I
Check 1st and 2nd Oscillator in,jection voltage.
I
l Check crystal Y1.
l Check Front End Aligllment (Refer to Receiver Alignment
Procedure).
l Check voltage readings of RF Anip, 1st Alixer and HI IF
~ Amp.
) l Make SIMPLIFIED GAIN CHECKS (STEP 2A).
1
LOW AUDIO Check Audio PA (Q410 & Q411) voltace readings on
schematic diagram.
Make simplified gain and waveform checks of audio and
squelch stages (Steps 2A
and 20).
a Make unsquelched voltage readings in Audio section
(Refer to
Receiver Schematic Dingram).
Check voltage readings on Channel Guard board.
HIGH DISTORTION AT LOW Set PA bias adjust R43 as specified under Service
AUDIO LEVELS (50 MW) checks in STEP 1 of TEST PROCEDURES.
IMPROPER SQUELCH OPERATION
l Check voltage readiugs of Squelch circuit (Refer to
Receiver Schematic Diagram).
Make gain and waveform checks oi audio and squelch
I stages (Steps 2A and 28).
DISCRIMINATOR IDLING TOO See if discriminator acro
is in centcr of IF bandpass.
FAR OFF ZERO
EQUIPMENT REQUIRED:
1. RF Voltmeter (Similiar to Boonton Model I
Millivac Type MV-18 C).
2. Signal on receiver frequency (below satul
Correct frequency can be determined by zc
the discriminator. Use 1,000 Hertz sign;
3.3 kHz deviation for audio stage.
PROCEDURE
1. Apply probes to input of stage and systen
tive (-10 VDC). Take voltage reading (El
2. Move probes to input of following stage :
system negative. Take reading (E2).
3. Convert readings by means of the iollowir
mula:
E2
Volatge Ratio =
1
4. Check rcsults with typical voltage ratio:
on diagram,

IP 3-VOLTAGE RATIO READINGS + 7406470MHZ
MENT REQUIRED:
RF Voltmeter (Similiar to Roonton Model 91-CA or
Millivac Type MV-18 C).
Signal on receiver frequency (below saturation).
Correct frequency can be determined by zeroing
the discriminator. Use 1,000 Hertz signal with
3.3 kHz deviation for audio stage.
DURE
Apply probes to
input of stage and system nega-
tlve (-10 VDC). Take voltage reading (El).
Move probes to input of following stage and
system negative. Take reading (EZ).
Convert readings by means of thc lollowing lor-
muln:
E2
Volatge Ratio = -
1
Check results with typical voltage ratios shown
on diagram.
RF AMP IST MIXER
Q I QI
J441
ANT
IST OSC IST MULT(X4) MULT(X3)
Q 2 Q I
2444
t~ NT
xrnL OP COM FREO-
OPER FREU-I2 4MHZ
24 J442-4
-
L2
-
STEP 2A-SIMPLIFIED VTVM GAIN CHE(
HELICAL
RESONATOPS
L44 - L423
L4lO
L412
-
a1
ORCOM
-
EQUIPhlENT REQUI RE11 :
L?"
L4l3
-
L5
-
-
2. Signal Generator (measurements h1560 or equiv.)
PRELIhlINARY STEPS :
-
1. Set VOLUME control for 4.18 volts across 3.5-ohm
load.
If this cannot be obtalncd, set to approx.
70'5 oi max. rotation.
2. Set SQUELCH control fully rountcrclockwise.
-
Tlii?
-
3. Rccelver should be properly aligned.
-
T3/T4
4. Connect VTVM hetwcen system negative and points
indicated by arrow (except for
1st MULT which
references chassis ground).

IST MIXER
QI HI IF
AMP
Q I
L---x3 *L-_
I
C. 361
I 2ND MIXER
I Q 2
I
I IST LO IF 1 2ND LO IF
I AMP I AMP
I 03 I QI
I I 1
HCL~CAL
TZ
- RESOhATORS
L414 - L423
25MV
INJECTION
VOLTAGE
MULT(X3) MULT(X2) 2ND OSC
Q 1 Q2 Q4
T31T4 L424
X READING TAKEV WITH BASE OF ZND
OSC SHORTED TO SYSTEM
hlEGITlVE
XX REMOVE SHORT ON 2ND OSC 8 INCREASE
INPUT SIGNAL LEVEL TO 4PPRDX IMV
,442-1 TO OVERHIDE INJECTION VOLTAGE
\
\
'-x.
=IED VTVM GAIN CHECKS
--~
.-
-.
~- .
~. -~
SIGNAL GLNEWATOR
INPUT AT J441
MAINTAIN SETTING AT UNMODULATEO UNMODUL ATED UNMODULATED UUMODULPiT
DISCRIMINATOR ZERO INCHElSE GENERATOR lNCREASE SIGNAL INCREASE SIGNAL INCREASE SlGl
PROCEDURE OUTPUT UNTIL VTVM GENERATOR OUTPUT GENERATOR OUTPUT GENERAT09 0L READING ON 1.5 V FROM ZERO UNTIL FROM ZERO UNTIL FROM ZERO U
SCALE DECREASES VTVM READING DE- VTVM READING DE- VTVM READIN
5y 5~ MV
CREASES BY 5 %
CREASES BY 5% CREASES BY
0.8 VDC 0.25 VDC GENERATOR OUTPUT GE~ERATOR OUTPUT GENERATOR OUTPUT GENERATOR OL
SHOULD BE aPPRoX SWLD BE nPPRox SHOULD BE APPROX SHOULD BE AF
READING 20 MILLIVOLTS 600 MICROVOLTS 5 MICROVOLTS 0.3 MICRDVOI
.surements Tr1560 or equiv.)
r 4.18 volts across
3.5-ohm
be obtained, set to approx
ully counterclockwise.
operly aligned.
system
ncxative and points
Kcept for 1st MULT which
3und).
STEP 26-AUDIO & SQUELCH WAVEFO1
EQUIPMENT REQUIRED:
1. Oscilloscope.
2. Signal generator (measurements M560 to equivale
PRELIMINARY STEPS:
1. Set VOLUME control for 4.18 volts across 3.5-oh
load. If this cannot be obtained,
set to apprc
70% of max. rotation.
2. Set SQUELCH control fully counterclockwise.
3. Receiver should be properly aligned.
4. Connect oscilloscope between system negative ar
points indicated by arrow.

T LO IF 2ND LO IF I IST LIM 2ND LIM 3RD LIM
AMP I AMP Q2 Q3 Q 4
Q 3 I QI
I AUDIO Al
I 06
I
I
3.58 LOAD AT SPEAKER)
JELCH WAVEFORMS -*
UNMODULATED
INCREASE SIGNAL
GENERATOR OUTPUT
FROM ZERO UNTIL
VTVM READING DE-
CREASES BY
5%
GENERATOR OL~~PUT
SHOULD BE APPROX
5 MICROVOLTS
I I I I 1 I
snts M560 to equivalent). RC- 1828 B
I I I I I I
UNMODULATED
INCREASE SIGNAL
GENERATOR DUTPUT
FROM ZERO UNTIL
VTVM READING DE-
CREASES
BY 5%
GENERATOR OUTPUT
SHOULD BE APPROX
0.3 MICROVOLTS
0.5 MS/DI'
50 MILLIVOLT
0. I V P-I
3 volts across 3.5-ohm
btained, set to approx.
SCOPE SETTING
counterclockwise.
y aligned.
en system negative and
l MICROVOLT
uNMODULATED
-0.6 VDC
05 MSIDIV
I VDLT/DIV
2 V P-P
HORIZONTAL
VERTICAL
PEAK-TO- PEAK VOLTAGE
NO SIGNAL INPUT
- 2 VDC
0 5 MS/DIV
1 VOLTIDIV
14 V P-P
STANDARD SIGNAL- I
~~$~~~~~DA~yR~~~FRwf
WITH 33KHZ DEVIIOKHZ W 01
0.8 VAC
0.5 MSIOIV
2 VOLTSIDIV
5.7 V P-P (NOISE)
0 5 MSIDIV
I VOLTIDIV
I V P-P (NOISE1
0.5 MYDlV
0.5 VOLTSIDIV
3 V P-P INOlSEl
STANDARD SIGNAL
0.75 vAc
STANDARD SIGNAL
0.55 vAc
STANDARD SIGNAL
0.15 VAC
STANDARD SIGNAL
2.3 vAc
STANDARD SIGNAL
0.05 VAC
STANDARD SIC