wrote:
http://worlditc.org/h_07_meek_spiri_029_041.htm

Scroll down and see the schematic for the machine. What's interesting
is that they use 10-12 ft. antennas (which today could be replaced by
simple CB antennas).

For a more clear schematic and samples of the voice contacts using the
tones:

http://worlditc.org/k_06_spiricom.htm

Hope this helps you to get a better understanding of the equipment and
theory involved with this time-consuming research.

Jeff


Ok, well to me that is wierd but interesting. So, if it is not
strictly necessary to use any one RF frequency, perhaps, legalities
aside, it would do no harm to use one of the FRS channels. FRS is FM
and incoming signals should not disturb your AM experiments as long as
your receiver is close to the signal generator's antenna. I do not
imagine that any spirits would need a widely separated set of antennas
to fit between, so therefore a low power signal such as what comes out
of your signal generator should do for closelt spaced antennas. How
far apart? heck if I know. 2 feet? Since you are using a signal
generator, your power level can be very low so as to not interfere
with others, and an antenna for transmit or receive at those
frequencies need only be 4-5" long.

FRS:
462.5625 GMRS Simplex / FRS Ch. 1
462.5875 GMRS Simplex / FRS Ch. 2
462.6125 GMRS Simplex / FRS Ch. 3
462.6375 GMRS Simplex / FRS Ch. 4
462.6625 GMRS Simplex / FRS Ch. 5
462.6875 GMRS Simplex / FRS Ch. 6
462.7125 GMRS Simplex / FRS Ch. 7
467.5625 FRS Ch. 8
467.5875 FRS Ch. 9
467.6125 FRS Ch. 10
467.6375 FRS Ch. 11
467.6625 FRS Ch. 12
467.6875 FRS Ch. 13
467.7125 FRS Ch. 14

You might also try the "ISM" frequencies, as long as there are no big
machines operating on them and radiating powerful signals, you should
be fine. There is a listing of those frequencies he
www.tscm.com/FCC47CFRpart18.pdf

It seems to me the biggest challenge is to build the spectrum
generator for all those audio tones. Perhaps an old electronic organ,
one with the feature of a separate tone oscillator for each key, could
be used. You can pick off the sinewaves at the oscillators if it is an
old enough model.

PJ