Topband: Finding powerline noise

w2fca@cs.com w2fca@cs.com
Fri, 13 Dec 2002 07:41:56 -0500


"Garry Shapiro" <ni6t@garlic.com> wrote:

>On 160, though, the most common sources are usually not due to powerline
>hardware but customer-owned "inadvertent radiators" such as unfiltered (read
>"cheap") dimmers, touchlamps, doorbell transformers, fishtank heaters,
>defective flourescents, and poor grounds---i.e. the usual suspects. This
>time of year, add Christmas lights, which make holiday contesting all that
>much more fun. For me, these have proven much more difficult, as they are
>not on all the time, not all neighbors are cooperative, etc.

I found a new "inadvertent radiator" this past weekend. During the contest, I suddenly started getting noise that sounded like a low frequency fuzz tone guitar. Totally wideband. Over a period of a minute the overall tone went up in frequency then with a short burst, stopped. Ten minutes later, it came back and did the same thing. Then 10 minutes later again. Went through the whole of Friday night that way. Sat night I happened to be outside and noticed that my neighbor had one of those sodium vapor type lights on his barn that go on at dusk. His, however, was coming on then going out. Every ten minutes. Apparently those things throw RF when starting up. Not a problem when they go on once but it seems as they age age they tend not to stay on.
Something to check for in your neighborhood if you have a cyclic noise.

Frank
W2FCA