I had a similar issue with a TenTec power supply next to a TenTec transceiver. The solution was to move the power supply.
Chuck Jack Hawley KE9UW Sent from my iPhone, cjack > On Sep 28, 2019, at 12:35 PM, RIchard Williams via Elecraft > <elecraft@mailman.qth.net> wrote: > > Conrad, > I had the same problem a few years ago when I placed my Alpha 9500 on the > left side of my K3S. After much perturbation, I finally figured what the > issue was. The power supply for the Alpha 9500 is on the right side of the > Amp, and the isolation transformers for the line in and line out are on the > left side of the K3 (K3S). When in such proximity, the magnetic fields > interact, and induce hum when using line in on the Elecraft radios. My > solution ended up being easy. The transformer in my Alpha was an old type, > and I was able to switch it out with the new model with (I think) is a > toroidal core, and that solved the problem. > Dick, K8ZTT > > > > > > > > > > I put up a new 6m antenna mainly for EME and I was so looking forward to > using my K3S. The RX is great, I run it in parallel with 2 other receivers > and it works very well on EME. However try as I might I cannot get rid of > some quite bad hum on the TX Audio. I am using USB and before you ask yes I > have got a low impedance ground from the PC to the K3S although removing it > makes absolutely no difference. What did make a difference was moving the > radio away from sources of magnetic fields such as monitors. However I > cannot get rid of it completely. It also increases or at least changes when > I put my hands on the radio. > > I have a few other radios located nearby and close to a monitor, pc or PSU > and they do not suffer from this at all. Is this a common problem, is it a > bad ground in the audio path internally or magnetic coupling into an audio > transformer? > > It is completely impractical for me to move my radios 10 feet from any > magnetic fields. Short of wrapping the radio in mu metal I really do not > seem to be able to fix this. > > Any ideas? I have read and understood and followed Jim K9YC's advice and > this works perfectly for my other 3 radios. I am really at a loss. > > 73 > > Conrad PA5Y > ______________________________________________________________ > 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 ro...@mulzer.de > > ______________________________________________________________ > 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 richarddw1...@yahoo.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 c-haw...@illinois.edu ______________________________________________________________ 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
