Batboard

any suggestions on buliding a rf screen room? I basically just need to block portables and mobile(uhf) from hitting repeaters and cloging up the tac channels during testing and repair.I have priced a few but there is no room in the county budget. I would like to build a free standing open to the air room, about 8x8 and 7 or 8 feet tall to shove me and a laptop/service monitior in.

Good ones cost money even to build. Maybe some of the buy/sell guys know where you might best place a WTB ad for a used faraday cage. I have seen some get scrapped because there were no buyers. Trying to decouple from the outside world and still have fresh air with electricity inside gets expensive.

You can buy brass or copper screening by the roll (meant just for this purpose) and just wrap a small room with it. I don't know how effective it will be. The Mythbusters made something similar for one episode where they were testing radio effects on avionic equipment. They built a small frame with wood, then attached the screen all around it. In typical Adam (act-before-thinking) fashion, he never built a door so he had a sealed cube with no way to get in.

The less joints the better. Gasketing material would certainly help, but just overlapping the screening, or having some on the inside you can use to seal the door opening might be helpful.

Bob M.

We have a Lindgren commercial 8 x 10 screen room. It was expensive but it works soo much better then the home brew ones we had at our other location.

In our case leakage is important with 9 voting sites for a 100 square mile city. For testing mobiles we must use double shielded cables or we get into the system.

The FBI lab in KC has one. They used some sort of copper cloth material and a wood frame. I heard it cost right around $1000.

This place seems to sell fabric to make your own.

http://www.lessemf.com/fabric.html

Bob M.

i love this site, thanks for the info guys.

Don't you have any mutual aid conventional channels (e.g. VTAC, UTAC, or 8TACXX) programmed into the radios that you can use for alignment?
Seems a lot easier and cheaper than building a screen room. I remember back when I was doing VHF repairs at my County SO we used our intercity channel that was on 155.370 to align the radios.

Ummm, any reason you are not using a dummy load?