13 Nov 2022

XBM80-2 QRP transceiver


Today, I had an email from somebody in the Netherlands about this transceiver.  He was getting no audio. Recently someone told me that crystal earpieces do not like DC. If this is correct, I suggest a capacitor is added between the collector of the audio transistor and the crystal earpiece. A 0.1uF or greater should be suitable. I also suggested that the audio transistor must not be in saturation. If need be, the bias can be altered to put the collector of the audio stage to mid-rail.

As I always say, do not be afraid to experiment.  If the circuit works better with different values then change them! With something this simple you could always start again, HI.

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