My blog post was mostly about providing clean mic bias with the KX3 for electrets that get bias from both tip and ring, like the Yamaha CM500.
Give it a quick read, it might answer some questions. http://observer.wunderwood.org/2015/08/16/yamaha-cm500-headset-with-ptt-on-elecraft-kx3/ wunder K6WRU CM87wj http://observer.wunderwood.org/ (my blog) On Aug 16, 2015, at 9:20 PM, Jim Brown <j...@audiosystemsgroup.com> wrote: > On Sun,8/16/2015 7:17 PM, Brian Denley wrote: >> Don't electrets have to be powered (voltage applied) where dynamics do not? > > Right. > > On Sun,8/16/2015 8:00 PM, James Wilson wrote: >> Yes, the electret mics do require a small amount of power - Elecraft >> and others call it BIAS voltage. > > It's called bias because it IS bias -- electret capsules have a very high > output Z, so they use a FET follower as an output stage. The voltage provides > bias for that output stage. > >> Fortunately - with the K3 and K3S and very likely the KX3 also - that needed >> bias is available and can be turned on or off with a menu selection. > > Virtually all modern rigs (within the last 30+ years) provide V+, usually > about 8 V, on one pin of the mic connector. All it takes to use that for bias > is a resistor in the range of 5K ohms from V+ to the mic input. > > 73, Jim K9YC > ______________________________________________________________ > 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 wun...@wunderwood.org ______________________________________________________________ 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
