Thanks for your thoughts. I looked at things here just now, and found that (1) unplugging my amplifier's power cord and (2) disconnecting an unused 50' run of RG-213 from my main TX antenna switch drastically drops that noise. :-)
I thought the noise pickup was somehow related to the low F/B (10 dB) of my NE-SE Beverage. That now appears to be a different issue --to be solved another day, since it's still considerably superior to the inverted-L for receiving. 73, Mike www.w0btu.com On Sun, Mar 2, 2014 at 8:27 AM, Tom W8JI <[email protected]> wrote: > I'm not saying that there's not a case for suppressing common mode as you >> and others suggest. >> > > It all comes down to impedance ratios and signal levels. Any choke or > filter is like a pi network or attenuator pad. It is ***always*** more than > the series element alone. > ... > > I do have a problem here lately with RFI from an electronic fluorescent >> ballast on 160 (10 feet from where I operate the radio), and I'm not sure >> how it's getting into my NE Beverage. Big #43 beads on the ballast leads >> didn't fix it. But that's another story. >> > > There are two forms of noise egress, common mode and differential mode. > ... > It seems very few people look at the system, which isn't that hard to do. > > _________________ Topband Reflector Archives - http://www.contesting.com/_topband
