On 20 Apr 2007 08:53:23 -0700, Chuck Gould
wrote:

Also makes one wonder about VHF. Some of the broadcasts in that band
run continuously (like weather), while of course most use is sporadic.

Not likely. Marine VHF transmissions are very low powered compared to
the signals of VHF broadcast television transmitters which operate
relatively close in frequency, and have done so for 60 years.

On the other hand, cell phone signals of the new digital PCS variety
are at frequencies more than 10 time higher, and are relatively new to
that radio spectrum. One fact that may lend credibility to the bee
theory is that the sun also emits electromagnetic signals in about the
same frequency range as the newer digital cell phones. Consequently
if bees were somehow using that solar radiation in some way for
navigation or orientation, that could be a possible link.

My gut feel however is that this is probably related to chemicals in
some way. Perhaps a new pesticide formulation, fertilizer, fuel
additive, or something similar.

GPS is extremely unlikely given the low power density of the signals.