Network Card RF Noise Pollution

[kb5udf]

I've tracked down a rather severe RF noise/interference problem as being from what I believe to be my pc's built in LAN adapter (S8-9 on most HF bands). Is there any chance giving all of my HF gear a common ground (ft-857, AT-200 pro tuner, and PC) would help?

I suspect integrating the computer in a common ground might only make it worse, but I'd like suggestions before I go through the trouble of trying.

 

[Al42]

Depends entirely on what kind of noise it is and where it's coming from. Radiated by the card? Coming through the power line? Radiated by the network cable? Something else entirely?

 

[kb5udf]

Rule out #1

At this point I can rule out the power cord as said interference also affects
battery powered radios.

 

[ka3jjz]

No that doesn't rule it out at all - the power cord can be acting as an antenna for the radiation. If indeed it is the card that's causing the problem, can you isolate it? Put ferrite beads on ALL leads leading to/from the card (that might be a tough call with ribbon cable...)? Like Al mentions, if the network cable is the culprit, can you substitute a shielded cable of some kind? Perhaps put a choke on it? Do the same with the power cord - in fact, I would put a choke on ALL power cords in that circuit. It's clear that a little homework is needed here.
Since you have a battery powered radio, you might be able to use it as a crude signal sniffer to see the general area where the interference is strongest. Not the best solution, to be sure, but it would be a place to start. 73s and GL..Mike

 

[woody_461]

Umm...If you have a router check that out too.They are notorious for RF.Possibly the modem tonly way I could get rid of RF noise on HF was to go wireless.I had RF interference all through the radio spectrum.There was quite a lengthy thread on RF interference here.

 

[wb0blv]

RF Noise on HF

I don't know about ethernet cards making noise.. But my 17" LCD Monitor makes noise on 80 (3868MHZ) and I have been fighting this for about 3 months..

I know CRT monitor will make noise, but was suprise to see and LCD doing also>>

IFY to all

Lee WB0BLV

 

[n3ijw]

what are the network cables plugged in to?

I had a Linksys BEFSR41 router that was a real noisemaker on HF.

 

[n4yek]

Had a similar problem, even though the computer has its ground through the power line,
it still has a long way to go through the line itself to reach the electric ground point.
I grounded computer and radio together then to the ground rod i had hooked to the radio.
Didn't get rid of all the noise, but it was signifigantly reduced.
Also you might want to check your power strip if your computer is plugged into one.
I had a cheapo dollar store power strip, one time, that created noise because it was not
allowing the ground prong on the cord to be connected to the ground prong on the outlet.
Danny
N4YEK