On Apr 19, 2010, at 12:37 PM, Jim Brown wrote: > On Sun, 18 Apr 2010 19:00:19 -0400, Bill Coleman wrote: > >> I found that putting a snap-on ferrite core around the power cord reduced >> the spur to an S5 indication. A similar reduction could be had by placing > >> snap-on ferrite around the power output leads. > > Study my tutorial on RFI and ferrites. > > http://audiosystemsgroup.com/RFI-Ham.pdf > > Most snap-on ferrites are designed for maximum effectiveness in the 150 MHz > range. ANY "snap-on" ferrite is next to useless on 160M unless multiple > turns are wound around it.
Please read the whole posting. The snap-on ferrite was used as a diagnostic tool. It showed a reduction in the unwanted signal on both the AC mains and the output power leads. Even if the snap-on ferrite was not the optimal final solution, it was useful in identifying where the energy was being radiated from the box. I did not use snap-on ferrites in my eventual solution to reduce the RFI. Bill Coleman, AA4LR, PP-ASEL Mail: [email protected] Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ______________________________________________________________ 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
