Untitled DocumentIf you have problems hearing zero-beat when tuning your transceive this circuit can help you.
if zero-beat tone is ok the LED is brightest.


This circuit can receive input signal from radio speaker, earphone or ACC jack (AF out)PCB Size = 3.5cm X 3.5cm

Sample IC-7200, IC718, IC706 ... wire connection (Use signal from ACC adjustmentAudio input comes from the transceiver speaker line.
The DC source is usually from an accessory voltage jack on the transceiver.
Adjust the variable resistor using transceiver sidetone, decreasing level to the minimum value that will light the LED.
Be sure to provide a ground return for the DC and Audio inputs.

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