Table3-6--Continued
Step
Procedure
Normal indication
Possible cause of malfunction
Corrective measure
off-scale, rotate RANGE-DB
switch cw until meter needle
reads on-scale. Note reading
on 0-10 DB scale. The total
reading in db is the sum of the
meter reading plus the differ-
ence between the final setting
of the RANGE-DB switch and
its initial setting in 21 above.
23
For increased resolution, rotate
Defect within SWR meter.
Refer to SWR meter manual
EXPAND switch cw until
efficient in db of the unit under
meter needle reads on-scale.
test.
Note reading in db on 0-2 db
scale. Total reading in db is
the sum of the meter reading
plus the EXPAND switch set-
ting, plus the difference be-
tween the final setting of the
RANGE-DB switch and its
initial setting in 21 above.
24
Convert DB reading to VSWR
VSWR of unit under test is deter-
value using db (reflection coef-
mined from chart
ficient) to VSWR conversion
chart in chapter 2, section III,
of TM 9-4931-294-15/1.
Table 3-7. Operational Check and Troubleshooting Chart of Reflection Coefficient Measurement Setups in Frequency Range from 2 to
124 GHz
Step
Procedure
Normal indication
Possible cause of malfunction
Corrective measure
1
Turn POWER switch on SWR
LINE/CHARGE indicator lights.
Defect within SWR meter.
Refer to SWR meter manual.
meter to LINE ON.
2
Operate signal source in the ex
SWR meter indicates a deflection.
Defect within PTN modulator.
Refer to PIN modulator manual.
ternal square wave modulation
I
mode of operation. (Refer to
Defect within modulator.
Refer to modulator manual.
paragraph on signal source op-
erating procedure In chapter 2,
Defect within SWR meter.
Refer to SWR meter manual.
section III, of TM 9-4931-294-
15/1.) Adjust the RATE con-
Defect within signal source.
Refer to paragraph 3-13 of this
trol on the modulator to ap-
section.
proximately 1000 Hz. Allow
3-16