Yes. Headphone to mic distance gets short and feedback can happen from leakage.
Sent from my iPhone ...nr4c. bill > On Feb 5, 2020, at 10:44 AM, Richard Corfield <richard.corfi...@gmail.com> > wrote: > > > Even with monitor running into headphones? > > I was running the contest with monitor off at first, but I turned monitor on > only in response to my contact telling me my audio was garbled. That said, I > initially wondered if the garble was due to frequency drift not feedback. > Though if it was a monitor problem it would also manifest on HF and through > the vocal mic? > > I can try though. I know the headphones leak, closed as they are, as I've > picked up notification beeps when using the field recorder and monitoring on > headphones while recording my voice. > > - Richard > > >> On Wed, 5 Feb 2020 at 15:29, Nr4c <n...@widomaker.com> wrote: >> Turn down TX Monitor volume. >> >> Sent from my iPhone >> ...nr4c. bill >> >> >> > On Feb 5, 2020, at 5:23 AM, Richard Corfield <richard.corfi...@gmail.com> >> > wrote: >> > >> > I had issues with RF feedback on the MH3 during the UKAC SSB 2m contest >> > last night. It seemed intermittent. Result was terrible noise in Monitor >> > output (my headphones) and to the other station, so it affects the audio >> > input. With experiments at the time and this morning: >> > >> > >> > - Occurs when RF power is increased above 0 and when Mic Gain is >> > increased. I could operate with Mic Gain set low, obviously at reduced >> > power out. (Indicative of a feedback loop) >> > - Occurs with a dummy load. (Also when I moved the antenna away last >> > night). So is the loop internal or is it so sensitive the small leak >> > from a >> > dummy load is enough? >> > - Does not occur if I feed a stage Mic In through a field mixer (kit I >> > have to hand). The field mixer claims an output impedance of 150R and is >> > running at mic level to match the MH3 allowing same gain setup in the >> > KX3. >> > Mic Bias is turned off in this case. >> > - Does not occur on HF into the dummy load. >> > - Manifests as buzzing on 2m FM >> > - May result in phantom button presses on the KX3 Mic (I didn't think I >> > knocked the dial) >> > >> > As an aside - one station last night was loud enough to activate the "RX" >> > indicator which I take to be input overload. S meter was well over S9 but >> > not at the top. I didn't see anyone else at the site, unless they were >> > hiding the the woodland carpark but I saw no light there or on the summit >> > behind me. I hit ATT, should have swung the beam to try to null them. But I >> > guess the ATT and even maybe the input protection is after the 2m module's >> > input? >> > >> > My thought is I need to inspect the wiring in the mic. Or could there be >> > anything else I need to check? >> > >> > Thanks >> > - Richard >> > ______________________________________________________________ >> > Elecraft mailing list >> > Home: http://mailman.qth.net/mailman/listinfo/elecraft >> > Help: http://mailman.qth.net/mmfaq.htm >> > Post: mailto:Elecraft@mailman.qth.net >> > >> > This list hosted by: http://www.qsl.net >> > Please help support this email list: http://www.qsl.net/donate.html >> > Message delivered to n...@widomaker.com >> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
