It might be noise on the bias. Some people have reported that. With a mono plug, you’ll get the mic bias (clean) and the logic bias (not so clean, wrong voltage) mixed together.
Using a stereo plug or a stereo-to-mono splitter will give you just the mic bias. Details here: https://observer.wunderwood.org/2015/08/16/yamaha-cm500-headset-with-ptt-on-elecraft-kx3/ wunder K6WRU Walter Underwood CM87wj http://observer.wunderwood.org/ (my blog) > On May 14, 2020, at 11:15 AM, Bert <[email protected]> wrote: > > The original Heil headset with the HC-4 element didn't work with the KX3. > > I have now replaced the HC-4 with an electret, which sounded > great trying it with the KX3 before installing it in the Heil headset. > The electret, by itself, was plugged in to the KX3 with a stereo plug. > > After electret installed in the headset I have quite a lot of hum. The > headset mic is connected with a mono plug to the KX3. > > Any ideas why the hum appears after mounting the electret in the headset? > > Bert VE3NR > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
