Jerry, As I understand it, about 5000 ohms is a goal when deploying common mode chokes. Hence why K9YC says multiple turns through a core is needed. Sometimes multiple cores in series.
But as I read you email, I think I’d focus on what’s different or amiss with the K2 since the other rigs aren’t exhibiting the problem. I’m sure someone who knows the K2 will chime in… 73, David - N5DCH > On Sep 4, 2021, at 3:48 PM, jerry <je...@tr2.com> wrote: > > On 2021-09-04 14:31, Jim Brown wrote: >> On 9/4/2021 2:03 PM, jerry wrote: >>> I made up a short length of RG8/U with 4 Palomar 31-mix giant ferrite beads >> Palomar SELLS these cores, at high prices. Fair-Rite MAKES them. > > 31-mix is supposed to be the hot ticket for HF common mode > chokes. One turn through one core is supposed to be 98 ohms at 5MHz. So > four cores should give me about 400 ohms, which should give a worthwhile > attenuation in a 50 ohm system. Thanks for the references. > > It's interesting that I am not having any such problems with any > other equipment. My TS590S works fine. So did the K2/10 with my tiny linear. > And a QRP-labs transceiver. And a uBITX transceiver. And a ICOM IC706MKII. > None of this stuff is doing anything strange. > > - Jerry KF6VB > > > >> - a common mode choke. No difference. >> This is only a good choke at VHF. If your problem is HF, multiple >> turns must be wound through the core. Study choke recommendations >> here. >> http://k9yc.com/KillingReceiveNoise.pdf >> And here. http://k9yc.com/RFI-Ham.pdf >> 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 je...@tr2.com <mailto:je...@tr2.com> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > <http://mailman.qth.net/mailman/listinfo/elecraft> > Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm> > Post: mailto:Elecraft@mailman.qth.net <mailto:Elecraft@mailman.qth.net> > > This list hosted by: http://www.qsl.net <http://www.qsl.net/> > Please help support this email list: http://www.qsl.net/donate.html > <http://www.qsl.net/donate.html> > Message delivered to david.n5...@gmail.com <mailto:david.n5...@gmail.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
