I will check that out this evening. I also will check out what happens when I turn off the up/dn function in the menu. Currently it is on. My audio output is very clean. My local friends have scrutinized the audio and said it is excellent. I appreciate the input. I'll get back on my findings.
On Thu, Feb 28, 2013 at 9:41 AM, Don Wilhelm <[email protected]> wrote: > Rick, > > I would wager that your microphone ties the tip and ring together. If you > look at the 'pinout' for the KX3 microphone (page 5 of the manual) you will > see that Ring 1 is PTT/UP/DN. If that pin is grounded, it is the PTT > function, but if there is a resistance to ground on that ring, you will > have either the UP or DN function depending on the value of the resistor. > Apparently the voltage introduced by applying bias is causing your KX3 to > interpret that level as either UP or DN (and it keeps repeating). > > If you turn off bias, the the 'bias' voltage is supplied by the residual > voltage from the PTT/UP/DN detection circuit in the KX3. Although that > works, the voltage source being used for that bias is sufficient for the > microphone element, but it is 'dirty logic voltage' which can give you > noise in the microphone input. Turning on the KX3 Noise Gate can help > reduce that noise. > > I built an adapter for my CM-500 (which also connects the tip and ring > together) to eliminate that connection - one can use a stereo jack and a > stereo plug with the tip of the jack connected to the tip of the plug and > the shells connected together (no connection to the ring). I built my > adapter with a 4 circuit plug and brought out the logic ground (ring2) and > ring1 to a switch that I use for PTT, but that is not a requirement, just > my desire. > > BTW, tying the ring and tip together is not a problem for the K3 because > the K3 jack has no connection to the ring (that is why it is marked "Mono" > - the jack is actually stereo. > > 73, > Don W3FPR > > > On 2/28/2013 9:15 AM, Rick Robinson wrote: > >> This may be apples to oranges, but, I use a Pyle headset with my kx3 and >> mine works with or without mic bias. But.... if I have the mic bias off >> the >> radio goes into scan mode. Don't know why. Just thought I'd mention this >> in >> case your K3 acts the same way....Rick >> >> > ______________________________________________________________ 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
