CBWI October 2001 General Lee Transmitter Tune-up
With the RF power switch in the high position, key the mic and adjust VR13 until 10 Watts is indicated on the external power meter. Switch the RF power switch to low, key the mic and adjust VR16 to 2 Watts on the external power meter.
To set the modulation, inject a 30 mv 1 KHz signal into the mic jack with an audio signal generator with the mic gain control fully clockwise. In the AM mode and the RF power switch on high, adjust VR14 for the desired modulation reading on an external modulation meter. Then switch to low power and adjust VR12 for the desired modulation reading on an external modulation meter.
Clean loud modulation can be achieved by setting the modulation at 90% on both adjustments. VR14 can be set to maximum and there will still be some slight limiting. If all out maximum modulation is desired, TR37 can be removed. Both high and low power setting won't have any limiting.
Over modulation will have to be controlled with the mic gain control.With the mode switch in the FM position and the mic gain fully clockwise, adjust VR5 for no more than 4 KHz deviation.
Now with the radio in the AM mode on high power and fully modulated, adjust VR8 until the internal RF meter reads just over full scale. This will keep the needle from slapping of the end of the scale, shortening its life.
FM Deviation Adjustment
RF Meter Adjustment
AM Low Power Modulation Limiter
High Power Adjustment
AM High Power Modulation Limiter
Low Power Adjustment