One solution for router interference

[pepperpot]

See cg's April 10 post re a similar problem. Recently bought a Linksys WRT54G 2.4Ghz network router for the main home computer. Then found that on my Pro-96 I had a problem with scanning the county Motorola 800Mhz digital system in the same room as the router. Unless I hit Pause on an active TG, the scan got stuck on 154.2200 simplex with just noise. When I was far away from the router, no problem. I read the discussion and solutions in the April 10 post, then came up with a poor man's solution. Went out to the kitchen and got some aluminum foil. Made sort of a cradle around the one side of the scanner in effect blocking the router signal. It works and I can scan and surf at the same time again.

 

[cj5]

schematic plz!

Hey,

Would you happen to have a rendering of how you made the "cradle". I am having a lot of issues similar to yours. At this point all I can do is unplug and listen or vice versa. Do you know specifically what part of the router is giving off this interference? I've heard that CAT5 wire is to blame.

CJ...

 

[Al42]

I just set 154.22 into my scanner and took it over to my WRT54G. I get a pretty good signal on 22, and a weaker one a slot down, so the CPU clock on the router is about 154.215, or thereabouts. But the CAT5 cables should be loaded with broadband noise, so it's best to keep scanners away from them.

 

[cj5]

Shielded CAT5

Would using shielded CAT5 wire make things better or worse? I am in a very small apartment, and getting far away from the wires, is fairly impossible.

 

[jred184]

Cat5 won't cause interference. I wonrk in IT and use my scanner at work all the time. The computers and the wifi appliances are the only things that have messed with my scanner. The way the wires are wound around each other in the cable help eliminate any interference.


JRed

 

[cj5]

Not CAT5?!

Well I spent a good part of one day unplugging things around my house, to locate the electrical inteference. When I unplugged my router and/or my cable modem, the inteference was forever gone. So that leads me to believe that it has something to do with those apparatus or the apparatus connected to it.

 

[MacombMonitor]

I have a Netgear WGM124 Pre-N Wireless Router in my computer room, along with two computers, two LCD monitors, a color laser printer, an inkjet printer, a USB hub, two wireless keyboard/mice combos, and a Nextel phone! None of this appears to have any ill effect on my scanner radios that are only a few feet away, all currently using indoor antennas in the same room!

The Netgear is in a full metal enclosure...maybe that's the difference?

 

[woody_461]

I'm having the same problem with a Linksys BEFSR41.It's creating havoc throughout the SW bands all the way up to VHF-Hi.I've run out of ideas how to deal with it.Unplugging it immediately stops the offending signals/interference.

 

[MacombMonitor]

Ferrite chokes might help. Something like these:

http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=273-105

 

[MacombMonitor]

Here is another style of ferrite chokes:

http://www.universal-radio.com/catalog/misc/1778.html

 

[woody_461]

Thanks Bill.

I already tried that.I'm almost positive the Lan cables (CAT5) are the culprits.They're acting like a giant antenna.The RF interference is at a constant level throughout the house.Even the far corner on the second floor.

The only solution for me is to shut off the router.It's difficult however, with 3 other family members online.

 

[cj5]

Caught in the middle

Well I'd have to agree that it may be a LinkSys router issue. But I am not really sure. But I want to stick with blaming the router, because as soon as I yank the power, BOOM, the scanner goes right back into SCAN. The reeason why I blame the wiring, because when i unplug the router and simply use the Motorola modem, I eventually get the same type of inteference. Aren't these companies held to FCC regulations? If you think about it, a good chunk of Internet customers are using these cable setups, in growing numbers, that must add up to a lot of inteference. I don't know. I would have to admit that I am ignorant to this topic. But I live in area where the active frequencies are slim pickin's, so I am trying to access as much as possible, and it seems that this extra unwanted RF, is really a nuisance.

 

[MacombMonitor]

Re: Caught in the middle

The reeason why I blame the wiring, because when i unplug the router and simply use the Motorola modem, I eventually get the same type of inteference.

That doesn't rule out that the cable modem itself could be the source. :shock:

 

[jred184]

I have around 200 CAT5 cables running to my office. The only interference I get is from my computer itself. I turn it off, and I can scan with no problem at all. Check the router itself or the cable modem.

You could unplug all the CAT5 cables from the router. If you still have the problem, unplug the router, then the cable modem.

Now keep in mind I don't have ANY shorts or open wires in my CAT5. If you insist it is the CAT5, try using CAT6. It is the best you can use and is the most widely used for VoIP. Be sure that you use CAT6 jacks and not CAT5.


JRed

 

[Al42]

Re: Caught in the middle

Aren't these companies held to FCC regulations?

Yep - scanners, per FCC regs, have to accept any interference they get. Uniden's "complying" with that.

If you think about it, a good chunk of Internet customers are using these cable setups, in growing numbers, that must add up to a lot of inteference.

To licensed services, no. To scanners, yes.

 

[cj5]

FCC

Well, actually I was referring to the companies that manufacture cables/modems/routers. Aren't they held to FCC regulations too?

 

[Al42]

Re: FCC

Well, actually I was referring to the companies that manufacture cables/modems/routers. Aren't they held to FCC regulations too?

Cables, no. Routers and modems are considered office equipment, not home equipment, so the standards are lower.

Now my question:

How is it that I can use my scanner within a few feet of my modem and router, except for the frequency the router CPU operates on - and that signal disappears within 10 feet or so? What is everyone else doing to cause such bad interference? I use the modem (Motorola Surfboard), router (Linksys WRT54G) and a VoIP modem (Motorola VT1005) right out of the box. No chokes on my cables.

 

[MacombMonitor]

Not everyone is having problems...read my first post in this thread. I have a great potential for problems, but I'm not having any problems.

 

[woody_461]

Re: FCC

Now my question:

How is it that I can use my scanner within a few feet of my modem and router, except for the frequency the router CPU operates on - and that signal disappears within 10 feet or so? What is everyone else doing to cause such bad interference? I use the modem (Motorola Surfboard), router (Linksys WRT54G) and a VoIP modem (Motorola VT1005) right out of the box. No chokes on my cables.
************************************************
Good for you!....Maybe you're just lucky??

I'm using quality coax cable,and a highly shielded/designed radio (Icom R8500).I have found one Cat 5 cable that is suspect, however.Maybe it's a quality control issue with the cables.

That said, all my scanners/radios exhibit the same behaviour here.


*update* changed the suspect cable.Just a small improvement.Has to be poor shielding in the router itself.

 

[wesct]

i am also having problems with my router. my solution is to put it in my basement and run wireless- no cables to mess with and interference is not a problem.

wesct