(2) Adjust potentiometer R7708 for a
(a)
Signal
voltage
chart.
maximum indication on the ME-
26B/U.
Circuit junction
Signal voltage (rms)
I
(3) Adjust inductor L7704 for a max
4.9
mv
P7601-C
imum indication on the ME-26B/U.
3.0
mv
C7601 and T7601
A normal indication should be +3.2
5.7
mv
T7601 and C7603
5.6
mv
volts dc minimum.
Q7601 base
5.6
mv
T7602 and C7609
(4) Increase the 606A output to 300 mv
17.0
mv
R7605 and R7606
33.0
mv
T7602 and C7610
as indicated on the 411A. A normal
34.0
mv
Q7602 base
indication should be +4.5 volts dc
2.5
v
Q7602 collector
minimum.
27.5
mv
R7606 and C7611
(5) If the indication obtained in (3) and
(b) Dc voltage chart.
(4) above are low or absent, pro-
+dc voltage to
Circuit junction
ceed to d below.
ground (volts)
c. Bandwidth Test for 5.65-Mc A m p l i -
15.3
P7601-H
fier.
16. 3
C7604 and R7603
5.35
Q7601 base
(1) Adjust the 606A for a 411A indi-
5.55
Q7601 emitter
cation of 150 mv.
8.0
R7605 and R7606
7.6
Q7602 base
(2) Adjust potentiometer R7708 for an
7.66
Q7602 emitter
ME-26B/U indication of +3 volts
8.0
R7608 and C7611
dc.
3.1 (rectified
CR7602 and R7611
signal)
(3) Adjust the 606A frequency to 4.600
2.0 (rectified
P7601-K
mc and adjust the output level to
signal)
maintain a 411A indication of 150
(3) Remove the test signal and set the
mv. A normal indication should be
T S - 1 7 7 7 / V R M - l ON-OFF switch
+1.5 volts dc 0.3.
to OFF.
--
(4) Adjust the 606A frequency to 6.8.
(4) Replace the faulty part.
mc and adjust the output level to
(5) Repeat b and c above.
maintain a 411A indication of 150
m v . A normal indication on the
58. Isolating Troubles in Assembly A7700
ME-26 B/U should be +1.5 volts
dc 0.3.
Refer to figure 39 for circuit details and
(5) If indications obtained in (3) and
(4) above are normal, proceed to
a. Preparation for 5.65-Mc Amplifier
Tests.
e below.
(1) S e t T S - 1 7 7 7 / V R M - 1 s e l e c t o r
(6) If indications obtained in (3) and
switch S7902 to position 15.
(4) above are low, proceed to d
(2) Adjust Hf Signal Generator 606A
"below.
for a frequency of 5.650 mc with an
d. Trouble Isolation in 5.65-Mc Ampli-
output of O volt and connect it to the
fier.
test probe.
(1) Adjust the 606A for a frequency of
(3) Connect Rf Millivoltmeter 411A to
5.650 mc at a level of 18 mv as in-
connector P7701-M.
dicated on the 411A.
(4) C o n n e c t the ME-26B/U to con-
nector P7801-H and adjust to in-
(2) M e a s u r e the signal and dc volt-
d i c a t e + volts dc on the 30-volt
ages listed in the chart below to
scale.
isolate the faulty part. Measure the
ac voltages with an ME-30B/U; _
b. Gain Test for 5.65-Mc Amplifier.
m e a s u r e the dc voltages with an
(1) Adjust the 606A output for a 411A
ME-26B/U.
indication of 150 mv.
60
