Hi Bob, I wouldn't expect UHF/VHF transmitters like those you mention to interfere with a VLF receiver. Of course, if they were SO close that they induced significant currents in the wires of the circuit it would mess things up but then there would be lots of problems with all manner of electronics equipment in the same location. More typically, the types of things which interfere with WWVB receivers are things like switching power supplies, electric motors, malfunctioning street lights, malfunctioning high voltage power distribution equipment like transformers, CRT displays, computers, some fluorescent lights, etc. Sean On Sat, Aug 21, 2010 at 1:51 AM, Bob Axtell wrote: > The antennas are ferrite-loop design, similar to those used on AM > radios, but at a very low frequency, so the > amount of wire used is great and the ferrite TYPE is different. > > BTW, I drove around the neighborhood and I believe I've discovered the > reason(s) it probably won't work: > > 600 meters away was a cellular phone tower. > > 1000 meters away was the county police-band radio antennas, on 4 500' > steel towers. These are VERY powerful radiators. > > --Bob A > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .