clickwir

Phones don't have a very wide frequency spectrum... but I guess if you transmitted an RF signal within that spectrum it could be reproduced on the other end.

That could be interesting to play with.

edit: I guess that's actually how modems first started, with an idea similar to this

benjamin

Not quite. Modems convert data into sound (called an "analog carrier signal") and back. The word "modem" is actually a shortened version of modulator-demodulator.

Radio frequency is, by definition, outside of the spectrum that is audible to humans. If you generate a wave within the audible spectrum, it isn't RF.

qtiger

So you want to convert a RF signal to audible so you can transmit it via cellular, which is RF, and then convert it back to RF after the RF has been transmitted over RF. :loco:

Misa

what do u have in mind?

Bl@ck

couldn't have said it better myself
RF is pretty much any frequency from ~100KHz to just short of infrared at ~100GHz.
The Cellular frequency range or at least the PCS range is 1850-1990Mhz. That's 140MHz of bandwidth total and about 120MHz of usable bandwidth. not a bad chunk of spectrum for simple CDMA voice and light data applications. Especially since uncompressed voice can be almost flawlessly recreated on a 64k line.