RECEIVER CIRCUIT ALIGNMENT
a. Test Set-up
Refer to the diagram shown below:
EXT
RECEIVER ALIGNMENT SETUP
b. Sensitivity Alignment
1. Set the signal generator to provide 27.185MHz, 1kHz, 30%
modulation, Set the channel selector to 19«
2. Adjust LI01, L102, L103, L104 and L105 for maximum audio
output across the 8 ohm dummy load resistor. This alignment
should be performed by gradually decreasing the generator
output signal to the minimum level required for tuning to
avoid inaccurate alignment due to AGC action.
c. Squelch Circuit Alignment
1. Set a 50 ohm signal generator to generate a signal on channel
19 with an output level of 1000 microvolts, modulated 30f*
with a 1kHz tone.
2. Rotate the squelch control in füll clockwise direction.
3. Temporarily adjust RV101 for maximum audio output, and note
the audio output level. Then adjust RV101 so that the audio
output level decrèases by 6db.
4. Next, reduce the antenna input signal level to between 79^
and 447 micro^olts. The receiver should squelch. (The audio
output level should drop to zero.)
5. Reduce the antenna signal input level to zero, and adjust the
SQ control until the noise output just disappears.
19 PLUS -11-
To Next Page
Loading...
