Balanced Modulator
You can adjust the balanced modulator in receive mode. Connect an oscilloscope or diode probe and
DC voltmeter across R64. Then adjust C65 and R66 for minimum output. There should be two
points on C65 where the R64 voltage is at minimum (this verifies that you are not at the end of the
adjustment range). The dip in voltage across R64 should occur at approximately midpoint on R66.
There is some interaction between these two adjustments so you need to readjust each several times to
obtain the best dip.
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