How to fix possible RFI nightmare.

[RedPenguin]

I was having trouble with some of the fire frequencies in my area of Cambria County, PA, USA. I figured, well heck, I am going to try turning off every device I have, just to see if I can double check again if it's anything in my house, even though I also get it outside. I had my squelch turned up to 4 and was picking up noise on my ethernet cables running to and from my computers, my cable tv line, and even my telephone lines. I have a Linksys Router, which seems to be the biggest RFI nightmare, it was even making noise with my squelch turned completly up to 15. A switch was also making some noise. When around the TV very closely, it picks up some noise.

What on Earth do I do in this case? It's like almost everything is causing RFI.

A squelch of 4 seems to be ok for now, except occasional junk.

 

[ftwskies]

Wrap everything in tin foil? ;-) (I'm only halfway joking...)

 

[XTS3000]

Satellite IRDS cause TONS of interference. Seeing as I never use the RF output (CH3/ch4), I always use a 75 ohm terminator to prevent leakage. Surprizingly Rat Shack still carries these in their store.

Turn on the attenuator and do a walkthrough. That should help you narrow down where the offending signal is comming from.

Had the same problem here, and it turned out to be the RF output of the satellite IRD.

 

[RedPenguin]

Hmmm

The only thing that actually still makes noise with the attenuator on, is the Linksys router. Even the building lights, which I thought earlier don't seem to make noise with attenuator on.

 

[Zack08]

I have had success with decreasing the noise from various computer items by attaching those snap-on ferrite beads around the wires going to and from the device. It didn't fix it completely, but it has made it noticably better.

This will do nothing for the noise coming out of the device housing itself, but it will stop those signals from being radiated by the wires.

 

[zguy1243]

I assume that you have only indoor antennas on your radios? Using a outdoor antenna will cure the problem if you are hearing noise from household electronics. Getting the antenna farther from the noise source is the idea if the noise cannot be stopped.

 

[RedPenguin]

Hmmm

I was thinking that, but I do notice the interference also sometimes even outside also, so I don't know if it's outside and inside. It's like stuff like my router definably makes noise, but yet, I suffer some of the same issues outside also.

 

[trooperdude]

Wrap everything in tin foil? ;-) (I'm only halfway joking...)

They make spray-on nickle compound that really helps with plastic-cased
electronics.

http://www.web-tronics.com/12ozaersupsh.html

 

[RedPenguin]

I see

Wouldn't that cause issues with ventilation?

 

[k8mcn]

if you can, unscrew the external antenna from your router( i assume it is a wireless router)and see if the noise stops or decrease, if not then it is coming internally from the router. your best bet then would be to add ferrite beads as the post above suggested.

i have a D-link wireless piggybacked on a wired only lynksys, and have no noise from them anywhere in the spectrum.................if the noise is indeed coming as a spur from the generated signal from the router, them try a different antenna, grounding the router if you can, or as a last resort call customer service, they should have an rf engineer on staff........good luck

 

[DPD1]

If you think it's actually physically coming out of the router, you could also try making a little faraday box for it out of brass mesh... Might help.

Dave
http://www.dpdproductions.com
- Custom Scanner, Aviation, MURS, GMRS, Marine & Ham Antennas -

 

[trooperdude]

Ventilation

Wouldn't that cause issues with ventilation?

Hasn't to date.

I've sprayed the inside of CRT cases with the stuff, leaving the
ventilation holes open.

I covered the ventilation with brass mesh, masked those off and sprayed
the rest of the case.

Same with my Cisco ethernet switch and Linksys router.

I did add an additional 12vdc fan on the Linksys, but only because it's in a normally
hot location.

It's not a continuous spray sheet, but it does enough shielding to prevent most
problems even with the air holes.

I also use clip-on torroids on all cables, all power cables at a 90 degree angle to the
computer and audio cables, and good grounding.

YMMV

 

[Declared_Hostile]

If you think it's actually physically coming out of the router, you could also try making a little faraday box for it out of brass mesh... Might help.

Dave
http://www.dpdproductions.com
- Custom Scanner, Aviation, MURS, GMRS, Marine & Ham Antennas -

I've done that with routers, cable modems, USB hubs and wireless modems with good results. Another place where I seem to get bad RFI was from the cables themselves. Sometimes from the connector area and sometimes from the cable itself. If the plug itself was spewing RF wrapping in copper mesh helped. If it was the cable itself it was more difficult to deal with though sometimes something as simple as looping the cable several times would change the freqs of the RFI enough to solve the problem. Other times I've just chucked cable. That blue high dollar cable can sometimes be the worst as far as shielding. I found some really nicely shielded ethernet cable which I ended up making my own cables with which I rarely had problems with.

 

[mikepdx]

I have a Linksys Router, which seems to be the biggest RFI nightmare...

here's a page that might be of some help (all about Linksys router interference):
http://www.ldblake.ca/radio/netproblem.htm

I had the same problem that you have.
One of the ethernet cables connected to my router was
radiating severely. Replace it with a better quality one.
Much better now.

Tune your radio to the interference.
Remove ethernet cables attached to the router one at a time.
Declared_Hostile is exactly right: High dollar cable does not necessarily mean high quality cable.

Good luck!

 

[Declared_Hostile]

The cable I was thinking of is made by Belkin. Belkin snagless cat 5 cable. It has the little ears on the plugs so you don't rip the tab off the plug or snag it. Stuff is blue. RF spewing crap. Be warned.

 

[brwkem]

Other than the Belkin what cable is then recommended.
I have the blue stuff argghhh.

 

[Declared_Hostile]

You might just have to buy a couple of different brands and see which is best.

I just happened to come across a partial spool of cable that was being thrown out and it was really well shielded and I made up my own cables with it. I have no clue who made it. It has no manufacturer on it. It's just charcoal colored stuff I scored dumpster diving.