It might RF feedback. For me it was especially apparent when running the Olivia digital mode. I could hear a faint warbling sound accompanying the correct tones, sort of like an echo but not exactly. It was also there on other modes but less obvious. It disappeared when I used my dummy load. I finally traced it to a bad connector on the coax run to the antenna. After fixing that the sound is perfectly clean now.
73, Elwood, WB0OEW ______________________________________________________________ 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