Ken Fowler wrote:

On 1-Dec-2005, Phil Wheeler wrote:


Xref: number1.nntp.dca.giganews.com rec.radio.amateur.antenna:253561

BKR wrote:

Computers and computer components are regulated by the FCC.
They MUST NOT cause interferance to licenced radio services.
(like the radio stations you are trying to tune in.)
Make that clear to the vendor you got the power supply from!


Interesting thought but impractical. It could be the installation
(e.g., grounding) vs. the supply itself. Event if the PSU itself,
proving it would be a chore.


The noise from PC Power Supplies is usually radiated from the power cord and the house wiring. The
cause is often that the manufacturers cut cost by leaving out the L and C components of the line
filter. Usually you will find the place on the PSU circuit board to mount a bi-filar choke and two
or three capacitors. The capacitors are missing and the pads for the choke are jumpered. If you
can find an older junk PSU which has the components, just unsolder them from the junk board and
install them in your PSU. Sometimes the PSU's in Monitors have the filter components.

When I installed the filter in my old Pentium, the switch mode hash on broadcast band stations went
down by 30 db. Installing line filters outside the CPU Case had very little effect.

-ken-
I was in the HSC store in Sacramento and discovered some filters that were
inside the AC switch. I decided against them, since I wasn't sure about the
amperage. I would think though the chassis builder might include such
devices, but haven't checked. Tomorrow I'll order the corcom filter 10ek7 10
amps that someone suggested from a place in San Jose, CA. $5.00. I'll give
that a whirl. Looks like I'll have to cut the cord to put it in the line.

--
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet

Traveling in arid or desert country? Check your
boots well to see if you have a scorpion in them.
-- Survivorman, Discovery (SCI) Channel

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