Shielding solutions to isolate 2.4GHz transceiver

[Jay911]

Hey all,

This is about the only place I could figure this would fit..

I have two Canopy Wireless 2.4GHz modems that I use for my Internet service. One receives from the ISP's tower and the other is a "bounce" or repeater/reflector that allows me to act as a relay for the ISP's benefit, to provide coverage to other ISP subscribers. They provide a considerable amount of interference to my scanning receivers, pro radios for the fire department, and other comms devices.

I was thinking that if I made some kind of shield around them, like a reflector dish, I would be able to limit the RFI from spreading in all directions, and keep it pointing toward the ISP's tower and the other subscribers. I figured something like a wire mesh - like screen door material, but made of metal - would do the trick.

Anyone ever undertaken such a task? Got any pointers or a better suggestion for me?

Thanks in advance!

 

[ltjweiss]

"I figured something like a wire mesh - like screen door material, but made of metal - would do the trick."
wouldnt you have to use copper mesh or would any metal mesh work?

 

[whiskeytango]

u tried these yet?

Snap Choke Core - RadioShack.com

 

[Jay911]

I'm not sure those would do the trick, when my concern is interference between the modem/antenna mounted on the side of the house and the scanner antenna/radio antenna set in the window or on the side of the house. I am thinking that physical shielding keeping the RF from the modem from going anywhere but toward its intended destination is what I need.

Furthermore, Radio Shack no longer exists in Canada, and the "new" company it was turned into, "The Source by Circuit City", is only a dumping outlet for NexxTech junk, no real radio equipment.

As for copper vs. other metals, I seem to recall that some folks (Mythbusters?) have had success with brass mesh, but I don't know for sure what's truly necessary, which is why I'm asking.

 

[ltjweiss]

u tried these yet?

Snap Choke Core - RadioShack.com

those are more for power cords i think

 

[smason]

Have you isolated it to the modems? It could be the power supplies which would make it easy.
I know a lot of consumer switches and routers ship with switching supplies and they can be noisy.

 

[N_Jay]

Why are you sop sure that the interference is from the 2.4 GHz RF and not the data side and being radiated by the cable?

The solution to a problem, starts with knowing the problem.

 

[NCVFD1]

good luck same here it has to be the cable from the modem to pc

 

[jim202]

Many times the source of problems like yours stem from computer interface cables radiating.
You did not say just what frequencies that your having the problem with. My bet is the VHF band.
It may take you turning off one unit at a time until you locate the problem child. it may even be
several boxes causing the problem.

My suggestion is if you find it is coming from a CAT5 cable, is to change out the cable for a
shielded one. They are not easy to find and not any where as cheap as the standard CAT5
cables.

You may also find that you have a printer cable on your computer setup causing problems.
Don't forget to include your desk computer and any other boxes connected to it.

Just as a suggestion, you might try to describe the noise problem in detail so the rest of us
might be able to zero in on the source a little easier.

Jim

Hey all,

This is about the only place I could figure this would fit..

I have two Canopy Wireless 2.4GHz modems that I use for my Internet service. One receives from the ISP's tower and the other is a "bounce" or repeater/reflector that allows me to act as a relay for the ISP's benefit, to provide coverage to other ISP subscribers. They provide a considerable amount of interference to my scanning receivers, pro radios for the fire department, and other comms devices.

I was thinking that if I made some kind of shield around them, like a reflector dish, I would be able to limit the RFI from spreading in all directions, and keep it pointing toward the ISP's tower and the other subscribers. I figured something like a wire mesh - like screen door material, but made of metal - would do the trick.

Anyone ever undertaken such a task? Got any pointers or a better suggestion for me?

Thanks in advance!

 

[Jay911]

Sorry folks, I didn't get a thread reply notification because the person to reply after I last read it is on my ignore list. Interesting quirk in vBulletin I guess.

I'm certain it's not a printer cable - there's no printer here. It certainly could be the coax (not cat5) - though the interference persists even outside the house where the modems are, not just inside where the coax and power supplies are. As for the interference being mainly on VHF, that's not the case - radios are just as deaf at 150MHz as they are at 380MHz, thru 413MHz, up thru 866MHz, right up to 1090MHz. When the modems are not operating, comm signals return. The computer itself and its cat5 is not an issue - computer and router's power/data transfer status has no effect on the interference. I admit I've never tried running the powered coax without the modem connected, so the powered coax might be the issue.

Thanks for the helpful comments and suggestions, which I'll explore. As for the rude comments saying I should know what I'm talking about before I ask for help, those just fly right by and don't bother me in the least.

 

[code3cowboy]

A simple faraday cage would probably help.

What kind of antennas/feed line are the modems using?

 

[code3cowboy]

A simple faraday cage would probably help.

What kind of antennas/feed line are the modems using?

 

[BonziBuddy]

I thought the interference I was getting was coming from my wireless router.

It turns out it was coming from my xbox360 wireless radio or the controllers.