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| Joined: | Dec 12th, 2007 |
| Location: | Dunedin, Florida USA |
| Posts: | 38 |
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Is there any equipment that I can use as a receiver for the spiricom that would allow me to do away with the radio that I am presently using. The reason is to eliminate any possible radio reception and try to ontain pure spiricom voices without receiving any other none spiricom random voices or frequencys.
David,
I think Jeff's approach is the best advice on this one. About the only way I know of to eliminate the possibility of reception of radio or other electronic interference is to place both the transmitter and receiver inside a well grounded Faraday cage. This is really nothing more than an all metal enclosure that completely surrounds the equipment. It doesn't have to be solid like sheetmetal, it could be instead made out of metal screen with a mesh size about that of ordinary window screen. The last Faraday cage I built was made out of fine copper mesh screen and enclosed a room about 8 feet by 6 feet. I used 14 gauge, bare copper wire to connect multiple points on each wall, floor and ceiling surface to a main cable that was then connected to a long metal stake driven into the ground. It was pretty expensive but testing showed that once you were more than an inch or so away from the screen (inside the room) there were no detectable electronic signals.
You could probably use something smaller and less expensive to get adequate isolation. For example, I would expect that a 4 foot cube frame made from something like half inch diameter copper water pipe with conductive metal screen, or perhaps sheetmetal would do the trick. It would be best if everything you put inside the box is battery operated so there are no wires entering from the outside. You'll need a small metal door (sheetmetal or metal screen) so you can put things in and take things out. The sheet metal or metal screen of your box/cage must be electrically connected to a good ground. Metal water pipes in a house are often a good choice.
A simple way to test how effective your Faraday cage is to tune in a station on a battery operated radio and then put the radio inside the cage and close your door. If you can't hear any radio stations under these conditions it's an idication your cage is working.
Hopefully someone else reading this who knows more about the subject of Faraday cages will weigh in with some better suggestions and correct any of my amateur mistakes.
Bruce