default writes:

On Sun, 15 Jul 2007 04:01:59 -0000, wrote:

Hi,
I was helping my father in law (Joe) put up an "Eat at Joes" neon sign
in his kitchen. (looks awesome!) Anyway, its pretty close to a TV and
causes some interference on the lower channels. When we hooked it up
through a power strip it seemed to reduce the interference, but it was
still there. Is there anything (cheap) that can be done to reduce it
further. I heard that ferrite beads may help, but I'm not sure.
Any comments would be much appreciated.
thanks,
-Slick

One assumes the neon sign transformer or power supply is grounded and
the connections and insulators are clean and not arcing, and that
there are no motor driven switches to light different sign elements .
. . If the neon tubes have a metal frame holding them together - try
grounding that. (and stay safe - that is nothing to fool with if you
aren't experienced - put the plug in your pocket and work with one
hand - doubly dangerous with two people tinkering with it)

I would recommend a small filter like you find on switching power
supplies with the IEC connector. Cheap readily available as surplus
and pretty effective.

Put the filter on the sign not the TV - interference is always easier
to stop at the source.

I put a filter on my electric stove - the bimetallic range controls
were causing my modem to drop in speed when the stove was on.

I got a large core and wound a common mode choke with heavy copper and
used capacitors on the stove side (point one microfarad) line to line
and line to ground - no more problems.

A filter will probably do it. If not, look for possible ground loops.

More extreme would be to run a shield over the HV wires and power
cord.

Is it a heavy iron transformer or an electronic type? The latter may put
out a lot of RFI.

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