TM 11-5826-225-35
e. Modulate the signal generator 80 percent
i. Set the frequency of signal generator B
with 400 cps.
to 960 kc.
j . Adjust R136 full counterclockwise. Adjust the
f. Set the frequency of the signal generator
output of both signal generators to 100000
to 390 kc (the same as the receiver) as deter-
microvolt.
mined by a zero beat in the headset.
k. Adjust the frequency of signal generator
g. Disconnect the headset,
A for maximum indication on the audio output
h. Adjust the loop simulator control on the
meter.
test set so that the LOOP SIMULATOR in-
NOTE
dicator on the test set indicates 90 from the
Do not change the setting of the
indication on the BEARING INDICATOR on
GAIN control on the control unit.
the test set. Slightly adjust the loop simulator
control for a maximum indication on the tun-
of both signal generators to equal levels to
ing meter on the control unit, Peaking of
produce a 20-mw audio output on the audio
the tuning meter indicates maximum signal
output meter. The output of the two signal
pickup.
i. Set the BFO-OFF switch on the control
m. Adjust R136 (fig. 2-8) fully counter-
unit to OFF.
clockwise. Then adjust R136 five turns clock-
j. Set the GAIN control on the control unit
wise,
to approximately three-fourths of the fully
n. If necessary, adjust the outputs of both
clockwise position.
signal generators equally to indicate between
k. Adjust the output of the signal generator
10 and 20 mw on the audio output meter.
for 20 mw on the audio output meter. Maintain
o. Adjust R136 for minimum indication on
this indication approximately throughout. the
the audio output meter.
procedures.
NOTE
l. Unsolder and remove the cover of T1 (fig.
Balance (minimum audio output)
2-9 or 2-9.1).
should occur within three turns of
m. Set the TUNE control on the control unit
the setting in m above.
for 200 kc.
n. Set the frequency of the signal generator
3-16. First RF Amplifier Alignment
to 200 kc. Vary the frequency slightly in the
a. Connect the equipment as shown in figure
vicinity of 200 kc, and note the maximum in-
2-2.
dication in db on the audio output meter.
b. Set the switches on the control unit as
o. Reconnect the headset to the test set, and
follows :
(1) BFO-OFF switch to OFF.
to 200 kc as determined by a zero beat in the
(2) Function switch to ANT.
headset.
c. Set the switches on the test set as follows:
p. Disconnect the headset, and note the in-
(1) DC POWER switch to ON.
dication in db on the audio output meter. This
indication must be within 1 db of the indica-
( 2 ) RECEIVER-CONTROL switch to
tion noted in n above. If the difference is more
RECEIVER.
than 1 db, proceed as follows:
(3) GONIO DRIVE switch to ON.
d. Set the range switch on the control unit
2-9.1).
to 190-400, and adjust the TUNE control on
(2) Adjust the output of the signal gen-
the control unit to 390 kc.
Change 5 3-25