HARMONIC FILTER A1A2 ALIGNMENT
The alignment procedure is to be used in either of these d situations: (1) the
performance test calls a potentiometer out of adjustments or (2) the following is
replaced: RF Detector T1, CRT, CR2, C1, C2, C3, and C4. The procedure consists of
a preliminary setup and an adjustment procedure.
1. Remove the harmonic filter from the
1. Monitor VFWD, TP1, of the module
using the test DVM and a sharp probe.
2. Remove the cover from the power
2. Close the PTT switch on the handset
amplifier m odule of the test bed radio
and adjust the rf signal generator output
set. Disconnect the rf radio coax A1J1 at
to +19 dbm, turn the modulation level
the module and plug in the fabricated rf
control to obtain 20 watts output (2
coax cable in its place.
milliwatts indicated on the wattmeter
from the harmonic filter module.
3. Connect the test radio, module,
cables and test equipment as shown in
3. Adjust R1 to obtain +14.5 ±0.1 vdc
figure 4-5. Comply with notes 1-5 on.
at TP1 of the module with 20 watts module
4. Select the rf signal generator fre-
4. Change the DVM monitor point from
quency of 29.9999 MHz and an initial level
TP1 to A1A2P1 pin 14, VREFL (reflected
output of 0 dbm at radio. Set dc power
supply (7 amp) to +26.5v.
5. Adjust R2 to obtain the minimum
5. See the test ratio controls on the
voltage at pin 14. It should be between
control panel and amplifier/coupler as
zero and -3.0 vdc
6. Open the handset PTT switch.
FREQUENCY KHZ to 29,999.9
Mode to V-TR
7. Disconnect the +26.5 vdc input to
ANT SEL to 50 OEM (bypass)
the radio and remove the cables connected
VOLUME to ON
to the module.