Ref: Computer noise..

FWIW..I started this crusade back about 4 years ago to get
the noise out of my Icom radio.

The following is my track to a quieter system:

1. Got rid of the UPS system. It has a switching
power supply..they are cheap and radiate rf all
over the place. I moved to the Mandrake-Linux
OS..didn't really need the UPS..the OS has a file
system that takes care of itself on power failures
etc. It can recover after crashes.

2. When I got a new computer, I made sure that the
power supply was not the switching type and that
it was shielded and the latest FCC specs were
adheared to. Also, the newer cases have rfi
grounding and are shielded better.

3. Later changed to a quiet Router by Netgear.
The wall-wart bar power supplies on the wall
that was used a couple of years ago are also
the cheapo switching supplies that radiate
noise all over the house.

4. Went to a quiet DSL modem. The newer Zoom DSL modems
are state of the art..super quiet power supplies and
silent DA converters.

5. Fixed a noisy florescent light in the kitchen upstairs.
Noisy starter.

6. Went to a Flat panel monitor by Samsung. Much quieter
than my old regular 17inch CRT. This was one of the
main noise generators on my system.

This all over a 4-5 year period. Now I can listen to my
Icom receiver while browsing the net, the receiver is
within 4 foot of the Flat panel LCD monitor. Also, I
put in a RS 4 ft. ground rod just outside my window
for the Icom receiver.


Anyway, it can be done..but, it takes time and some
money.

Good Luck,

Leonard...
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On Sun, 14 Sep 2003 09:38:09 -0700, Tim Shoppa wrote:

I've got a few PC's in nice metal cases. I can actually run most of my
receivers near the PC without too much problem, as long as the receiver is
powered by batteries. But the instant I hook my sound card to the receiver,
or I run the receiver off of AC power, all the SW bands are filled with
S9 hash generated by the computer and network equipment.

What's the most economical and reasonable way to deal with this? Will
RFC's on the power, ground, and sound lines be good enough? Those snap-
together ferrite cores from Radio Shack help a little, but not
nearly enough. In a few weeks my computer-controlled TenTec
RX-320D arrives and I want everything to be in ship-shape by then.

The computer equipment isn't "just a computer". It's several PC's,
an Ethernet hub, a DSL router, a UPS, etc. By experimenting I've discovered
that the computers themselves aren't so bad... but the networking
stuff (a necessity, I'm afraid) is abysmal.

The situation is serious enough that I'm seriously looking into optical
fiber links... anyone have advice for a low-budget solution that way?
If I can put the RX-320D upstairs away from all the Computer stuff, and
run the audio and RS-232 over optical fiber, I'd be in heaven. While
I know where to start for RS-232 over fiber, I don't know anything
about the available audio-over-fiber options.

Tim.