Specifications

(a) Signal voltage chart.
Circuit junction Signal Voltage (rms)
P7701-M
R7703 and c7701
Q7701 emitter
Q7701 collector
81mv
15.55 mv
17.5 mv
1.75 v
(b) DC voltage chart.
Circuit junction
+dc Voltage to
ground (volts)
P7701-L
L7701 and C7702
Q7701 emitter
Q7701 base
CR7701 and R7708
P7701-J
16.0
14.8
6.95
6.75
2.9 (rectified
signal)
2.0 (rectified
Signal)
(3) Remove the test signal and set the
TS-1777/VRM-1 ON-OFF switch
to OFF.
(4) Replace the faulty part.
(5) Repeat b and c above.
e. Preparation for 47-Mc Amplifier
Tests.
(1)
(2)
(3)
(4)
.
Set TS-1777/VRM-l selector
switch S7 902 to position 18.
Adjust the 606A for a frequency of
47.000 mc with an output of 0 volt
and connect it to the test probe.
Connect the 411A to connector
P7701-B.
Connect the ME-26B/U to con-
nector P7801-H and adjust to in-
dicate + volts dc on the W-volt
scale.
f. Gain Test for 47-Mc Amplifier.
(1)
(2)
(3)
(4)
Adjust the 607A output for a 411A
indication of 200 mv.
Adjust potentiometer R7718 for a
maximum indication on the ME-
26B/U.
Adjust capacitor C7708, trans-
former T7702, and inductor L6705
for a maximum indication on the
ME-26B/U. A normal indication
should be +3.0 volts dc minimum.
Increase the 606A output to 300
mv as indicated on the 411A. A
normal indication should be +4.0
volts dc minimum.
(5) If the indications obtained in (3)
or (4) above are low or absent,
proceed to h below.
g. Bandwidth Test for 47-Mc Amplifier.
(1)
(2)
(3)
(4)
(5)
(6)
Adjust the 606A for a 411A in-
dication of 200 mv.
Adjust potentiometer R7718 for an
ME-26 B/U indication of +3 volts
dc.
Adjust the 606A frequency to 42.00
mc and adjust the output level to
maintain a 411A indication of 200
mv. Record the ME-26B/U indi-
cation.
Adjust the 606A frequency to 54.00
mc and adjust the output level to
maintain a 411A indication of 200
mv. Record the ME-26B/U indi-
cation.
A normal indication, noted in (3)
above, should be +1.0 volt dc ±0.25.
A normal indication, noted in (4)
above is +1.0 volt dc ±0.25.
(a) If indications obtained are nor-
mal, trouble isolation in assem-
bly A7700 is complete.
(b) If “ indications are low, proceed
to h below.
h. Trouble Isolation in 47-Mc Amplifier.
(1) Adjust the 606A for a frequency of
47.000 mc at a level of 165 mv as
indicated on the 411A.
(2) Measure the listed typical signal
and dc voltages listed in the charts
below to isolate the faulty part.
Measure the ac voltages with an
ME-30B/U; measure the dc volt-
ages with an ME-26B/U.
(a) Signal voltage chart.
Circuit junction
I
Signal Voltage (rms)
P7701-B
Q7702 base
Q7702 emitter
Q7702 collector
T7702 and C77109
Q7703 emitter
Q7703 collector
C7712 and CR7702
165 Mv
165 mv
120 mv
680 mv
150 mv
165 mv
1.74.V
1.72 V
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