Sounds like you still have some RF getting in on the speaker cables or maybe on the line-out cables. How much power do you run in JT-65HF? I run JT-65 on 144-MHz at 1400w with no issues like you have. I do not use a powered/amplified speaker, just and old National speaker console from the 1950's with plain speaker wire. My line-in and line-out cables are standard shielded audio patch cords from RS. But then I only run 1.5mw to my transverter on 28-MHz, so no significant RF coming out of the K3.
A quick test would be adding a .001 uF disc. ceramic bypass cap from the center wire to ground at the K3 on the speaker. The toroid apparently is helping according to what you write. Maybe shielded speaker wire would help? I would guess the audio is already transformer coupled to the K3 speaker output so an isolation transformer probably would not help. I do think this looks like RFI. 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-100w, 1296-60w, 3400-? DUBUS Magazine USA Rep [email protected] ====================================== ______________________________________________________________ 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
