TM9-4935-294-15/2
Table 3-16. U-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 2
R1505 out of adjustment
Adjust R1505 as indicated
U-band rf head under test
control to 15,200 MHz.
mw.
or defective.
in technical bulletin TB
for leveled operation as
9-4931-300-50, or re-
shown in figure illustrating
place, if defective.
setup for signal source lev-
eling in chapter 2, section
Broken connector pin in
Replace broken pin.
II, of TM 9-4931-294-15/1.
P701 (rf head connec-
Operate signal source in
tor).
CW mode of operation but
do not remove the second
Defective resistor R1507
Replace defective compo-
directional coupler. Connect
or R1401,R1402 or
nent.
Thermistor mount-power
choke L1401.
meter combination to the
second directional coupler,
Defective BWO tube.
Replace BWO tube as in-
and se RF LEVEL-
dicated 'in paragraph
LEVEL ADJ control for an
4-21.
indication of 2 mw on
power meter.
2
Disconnect thermistor mount
Power meter indicates 2
Defective directional cou-
Replace directional cou-
from second directional cou-
mw.
pler DC101,
pier DC101.
Pler. .Remove interconnec-
tion cable from PHASE
LOCK connector on rf head,
connect thermistor mount-
power meter combination in
its place, using a wave-
guide-to-coaxial adapter,
and operate power meter.
3
Same as 2 above.
Slowly adjust FRE-
The 2 mw indication on
R1505 out of adjustment
Adjust R1505 as indicated
QUENCY-MC control
power meter does not
or defective.
in TB 9-4931-300-60,
through its entire
vary by more than 1 db.
or replace, if defective.
range.
Defective BWO tube.
Replace BWO tube as in-
dicated in paragraph
4-21.
4
Disconnect thermistor mount
Adjust FREQUENCY-
Frequency measurement
Helix .voltage-shaper cir-
Adjust the circuits indi-
and replace interconnection
MC control in 560 MHz
system indications cor-
cuit out of adjustment
cated as outlined in TB
cable to the PHASE LOCK
steps, beginning at
respond to within 2% of
or defective.
9-4931-300-50 or, if de-
connector on rf head. Con-
12, 400 MHz, through its
the frequency indicated
fective, locate and re-
Change 1 3-60
