In article 9,
Conan Ford wrote:
If I recall correct from flipping through the Radio Shack catalog at the
age of 8 or so, to look at all the stuff I *couldn't* have, cordless phones
used to be around 27 mhz, and also some were 49 mhz. Same went for Radio-
Shack RC cars. The "better" models ran at 49 mhz.

Back in the '70s and early '80s, cordless phones used, as I remember,
5 channels around 1600-1750 kHz for the base station, and 49 MHz for
the handset. Both FM, but you could receive them fairly well on an
AM receiver. Later they switched to 46 and 49 MHz.

I heard one neighbor, in the 3.5 MHz ham band, complaining that her
phone wasn't working well. It turned out to have a stronger
signal on the second harmonic than on the fundamental.

Some of them of them used frequency inversion scrambling which I found
out was completely useless as, even though it was an FM transmission,
it could be heard perfectly well on an SSB receiver. (Or at least on
my R-1000 which can run SSB with the 12 kHz wide filter).

Now they run on 915 MHz, 2.4 and 5.? GHz. Good riddance.

I also remember reading that some "smart" phones put out a spurious
AM signal on their microprocessor's crystal clock frequency. Pre-bugged
phones.

Mark Zenier Washington State resident