This article is from the Low Power Broadcasting FAQ, by Rick Harrison email@example.com with numerous contributions by others.
The question of getting phone audio on the air was raised in
alt.radio.pirate in September, 1997. The following suggestions
DJ Bryce wrote: "Your best bet is the Radio Shack speaker-phone box.
Its easy to use, simple to install and is a good cheap interface.
Just tap off the speaker leads... and if you want to, pick up their
1:1 transformer for a buck or two, and that will clean up any hum or
buzz. It works for many a commercial station that can't afford a
Gentner or Telos."
Bungalow Bill wrote: "My scanner will scan the 49 MHz range, where
cordless phones operate. It has a headphone jack in the back of it,
so I bought a simple patch cable that just takes 1/8 inch to 1/4 inch.
Then I plug in the cordless phone, and tune the scanner to its
frequency. When someone calls in, just up the volume on the mixer,
and they're on! Simple, and elegant."