TM9-4935-294-15/2
Table 3-15. X-Band RF Head Test Chart
Test equipment control
Rf head control
Possible cause
Step
positions or operation
positions or operation Normal indication
of malfunction
Corrective measure
1
Set up, signal source, utilizing
Set FREQUENCY-MC
Power meter indicates 5
R1505 out of adjustment
Adjust R1505 as indicated
X-band rf head under test
control to 10, 200 MHz.
mw.
or defective.
in technical bulletin TB
for leveled operation as
9-4931-29950,or re-
shown in figure illustrating
place, if defective.
setup for signal source lev-
Broken connector pin in
Replace broken pin.
eling in chapter 2, section
P701 (rf head connec-
II, of TM 9-4931-294-15/1.
tor)
Operate signal source in
CW mode of operation and
Defective resistor R1507,
Replace defective compo-
connect 6-db fixed coaxial
R1401, R1402 or choke
nent.
attenuator in place of coax-
L1401.
ial termination at output of
setup. Connect thermistor
Defective BWO tube.
Replace BWO tube as in-
mount-power meter combi-
dicated in paragraph
nation to the 6-db attenua-
4-20.
tor and set RF LEVEL-
LEVEL ADJ control for an
indication of 5 mw on
power meter.
2
Disconnect 6-db attenuator
Power meter indicates 0.2
Defective directional cou-
Replace directional cou-
and thermistor mount and
mw.
pler DC101.
pier DC101.
connect coaxial termination
to output of setup. Remove
interconnection cable from
PHASE LOCK connector,
connect thermistor mount-
power meter combination in
its place, and operate power
meter.
3
Same as 2 above.
Slowly adjust FRE-
The 0.2 mw indication on
R1505 out of adjustment
Adjust R1505 as indicated
QUENCY-MC control
power meter does not
or defective.
in TB 9-4931-299-50 or
through its entire
vary by more than 0.5
replace, if defective.
range.
db.
Defective BWO tube.
Replace BWO tube as in-
dicated in paragraph
4-20.
4
Disconnect thermistor mount
Adjust FREQUENCY-
Frequency measurement
Helix voltage-shaper cir-
Adjust the circuits indi-
and replace interconnection
MC control in 440 MHz
system indications cor-
cuit out of adjustment
cated as outlined in TB
cable to the PHASE LOCK
steps, beginning at 8000
respond to within 2% of
or defective.
9-4931-299-50 or, if de-
connector. Connect fre-
MHz, through its entire
the frequency indicated
fective, locate and re-
quency measurement system
range.
on the rf head, FRE-
place defective compo-
(refer to figure illustrating
QUENCY-MC counter.
nent.
Change 1 3-55
