On Tue, 23 Oct 2007, Harry Veeder wrote: > On 22/10/2007 10:48 PM, William Beaty wrote: > > Small resonant coil-antennas behave as if they were extremely large, like > > long-wire antennas. But any unknown transmitter that's supplying the > > power would have to be fairly close and not miles away. > > Through his faraday cage?
Sure! If his faraday cage is not grounded, then all it does is smooth out the voltage pattern of the radio waves, so his whole circuit would see the same RF voltage sinewave. If his circuit was accidentally intercepting microwaves, then his faraday cage might be a fairly good shield. But for longwave RF (like below 100MHz or so,) a faraday cage only works if the circuit is grounded to the inside of the cage, not grounded to the Earth outside. Hmmm. It might be educational to get a small, old-style AM transistor radio, solder an Earth-ground to one of its battery terminals, then stick it inside a foil baking pan. These radios rely on a large tuned ferrite antenna, just like Ron's experiment. (((((((((((((((((( ( ( ( ( (O) ) ) ) ) ))))))))))))))))))) William J. Beaty SCIENCE HOBBYIST website billb at amasci com http://amasci.com EE/programmer/sci-exhibits amateur science, hobby projects, sci fair Seattle, WA 425-222-5066 unusual phenomena, tesla coils, weird sci
