[RFI] Lights flicker
Fri, 24 Sep 1999 16:31:12 -0700
How much power are you running, and how is the AC power feed to your
station configured? The first thing to check is whether or not your
station is drawing enough current on transmit to cause a voltage drop in
the AC supply wiring. It only takes a small change in voltage (a volt or
two) to to cause noticeable brightness fluctuations in incandescent
lights. Peaks on SSB are much shorter than the key-down intervals on CW
and in my experience don't produce nearly as much flicker. The fix, of
course, is a separate circuit to feed the radio, or at least the
For what it's worth, a ground rod 12 feet from your station is not likely
to be a good RF reference at HF, but then again, there isn't necessarily
any need to have an RF reference to the physical earth to avoid RFI.
There are tons of urban legends, folklore, and just plain wrong
information floating around the ham community about grounds, what they do,
and how they work, but thats a whole 'nother subject.
Eric Rosenberg wrote:
> I have a relatively new installation and noticed that when I operate
> CW, the lights flicker (As opposed to when I'm operating on phone).
> All the gear -- but not the electric service [couldn't manage that] --
> is grounded through a single point which goes to the ground rod ~ 12
> feet away (across hte room and outside).
> Any thoughts on what to do?
> Thanks in advance,
> Eric W3DQ
> Washington, DC
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