[mythtv-users] RF interf. gen. computer -- offtopic

Andrew Dodd atd7 at cornell.edu
Mon Mar 1 15:01:30 EST 2004

Quoting john lawler <maillist at tgice.com>:

> Hi guys,
> Sorry to bring this to the list as it's a bit offtopic, but I do bring 
> it b/c I imagine that my computer hardware is pretty similar to some of 
> yours.
> 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.  Here are the basic specs:
> Chaintech 7NIF2 mobo (onboard sound/video+svideo out/lan)
> Athlon XP 2400+ w/ retail box heatsink + fan
> WD 60GB 7200rpm HD
> Hauppauge PVR-250
> Crucial 512MB PC 2700 RAM
> and my first guess at the problem, this case and power supply package:
> http://store.yahoo.com/3btech/sipomiatxca2.html
> It's a Powmax brand case (and I assume power supply, though I've not 
> scrutinized it yet).  This is a Korean manufacturer, I think, but I 
> purchased it from a US retailer.  I think the power supply is FCC 
> approved (it's got a FC symbol w/ another C inside the first C).
> And the interference seems to be about the same whether the case cover 
> is on or not.
> Sorry for the somewhat sketchy details, but any leads on what I could 
> look at for RF sources here?  I've sent the retailer an email query, but 
> I'm sure they'll deny responsibility.  Also, I should mention that I've 
> not built my own machine since the Pentium 3 days, so I'm aware there 
> could be some new RF issues with which I'm not familiar.
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.

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