[mythtv-users] RF interf. gen. computer -- offtopic
tony at maro.net
Mon Mar 1 21:45:56 EST 2004
Andrew Dodd wrote:
> Quoting john lawler <maillist at tgice.com>:
>>I've noticed quite a bit of RF interference on radios in the house and
>>on some electrical ground-based intercoms whenever I switch on the new
>>myth box that I've put together.
> Some cheapo power supplies seem to be missing powerline filtering that was
> designed into them. (i.e. jumpers instead of chokes, filter capacitors missing).
> You may be able to solve a lot of problems with ferrite chokes placed on the
> power cables.
> Ferrite is your friend.
I've never seen a bit of difference on anything with ferrite cores.
Ever. But that's just me. And I've tried them on probably 30 devices.
Anyway, he's right though, it's cheap and still worth a try. Otherwise,
you can try throwing a small UPS / Surge (those $40 ones) on it. Many
of those will filter the power going to/from the PC and if it's feeding
that interference back out the line, it might just take care of it.
Besides, a cheap UPS is always a good deal better than NO UPS.
Also, is your house grounded? Many older houses have a three prong
outlet, but the third prong doesn't go anywhere because there's no
3-wire wiring in the wall. Someone along the years may have replaced
the 2 prong wall outlets with three prong, leaving the ground
disconnected. Proper grounding will take care of many noise problems.
Now if I could just get rid of the interference generated by my 27" TV.
If things aren't _just_ right, my LIRC serial remote picks up enough
interference to scramble the signal. Well, actually, what it does is
feeds random numbers constantly to the port even with no IR present. If
I turn the TV off it goes away, and the amount of white in the screen
affects the amount of interference. If I set the remote sensor just
right the problem goes away. And no amount of ferrite core helped the
problem, I tried.
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