Mixer Adjust

The page is heavily influenced by the Gemini AI response here.

Additional information about using the S Meter for this process is here.

Information about the RF Gain setting the S Meter is here. It doesn't have anything to do with alighning the mixer but was acquired in that context.

Equipment and Radio Setup

• Power off. Radio upside down. Discharge the filter capacitors if you think necessary
• Front panel AVC switch on
• Connect an RF signal generator to the antenna terminals using the attenuator circuit board. This board reduces a 1 mV signal to a 1 µV signal suitable for the antenna input.
• Set the signal generator output to 1 mV p-p. This is almost certainly too low (input to the antenna is 1 µV) but as you work through the steps below, you will increase it. In so doing, the 1st time you see the effect of the signal, you will have a rough idea of the radio's sensitivity. Ideally, it should be about 4 µV

Mixer Alignment

1. Power on. Allow enough time to reach thermal stability
2. Set the signal generator frequency to exactly 1400 KHz. Modulation 0%
3. Band switch to band 1. Tune the radio to exactly 1400 KHz. The band spread dial should be set to zero although it does not play a role for bands 1 and 2.
4. Slowly adjust C92 while watching your multimeter on the AVC line. Tune for the maximum negative DC voltage
   • Note: If the signal gets so strong that the AVC voltage climbs past -10V, turn down the output level on the signal generator
   • If you don't see anything at all, increase the signal generator output level
   • Repeat this process until you can see the effect of adjusting C92

Page: /Alignment/Mix/Adjust/Align_early_mix_adjust.shtml

Last modified: Sunday, 19 Jul 2026