TM9-4935-294-15/2
put of receiver. Slowly adjust -
display sequence of signal source
signal source no. 2 frequency
no. 2 tuning procedure in chap-
Defect within oscilloscope.
Refer to oscilloscope manual
output until display shown in
ter 2, section III, of TM 9-4931-
section A of the figure illus-
294-15/1 is obtained on oscillos
Defect within microwave receiver.
Refer to microwave receiver -
trating oscilloscope display se-
cope.
Manual.
quence of signal source no. 2
tuning procedure in chapter 2,
Poor connection or defective com-
Locate and correct poor
section III, of TM 9-4931-
ponent in test setup.
or defective component in
29415/1 is obtained on oscil-
test setup.
loscope. Phase-c signal g n a
source no. 2.
7
Alternately a d j u s t REF
Sequence of oscilloscope display Defect within microwave receiver.
Refer to microwave receiver
OSC FINE TUNE
and shown in the figure.
manual.
COURSE TUNE controls
Defect within signal source no. 1
Refer to paragraph 3-13 of
of signal source no. 2. Con-
or no. 2.
this section.
tinue adjustment until free-
Quincy difference between
mixer output and internal os
ciallator of receiver, as dis-
played on oscilloscope, is be-
tween 7 and 25 kHz. The se-
quence of oscilloscope displays
in this procedure is shown in
the figure cited in 6 above.
8
Set REFERENCE ATTENUA-
Microwave receiver NULL meter
Defect within microwave receiver.
Refer to microwave
TOR to 0 DB. Adjust level-set
indicates a null.
receiver manual.
attenuator no. 1 to obtain a
null on receiver NULL meter.
Poor connection in test setup.
Locate and correct poor
Fine-adjust NULL indication
connection in test setup.
by means of receiver POWER
LEVEL control.
9
Adjust matching network for
Microwave receiver NULL meter
Defect within matching network.
Replace matching network.
maximum indication on NULL
indicates a null.
meter, then null the meter by
repeating 8 above. If receiver
AGC VOLTS indication has
changed, repeat 1 above.
10
Connect attenuator under test
ATTENUATION DB counter in-
Defect within unit under test
Troubleshoot unit under test.
between A and B of the appro-
dictates attenuation of unit under
priate test setup diagram If
test.
necessary,remove adapter or
waveguide sections when in-
serting attenuator under test.
Adjust REFERENCE AT-
TENUATOR control to obtain
Change 1 3-25
