At 11:26 AM 11/13/2004, you wrote:
[EMAIL PROTECTED] writes:
> I also had a friend who discovered that old pay telephones used to use
> the sound of the falling coins striking a bell to determine whether the
> money was properly deposited in the phone.
Payphones later used frequency-shifted DTMF tones to signal the deposit of
each coin. I changed the crystal in an accoustic speed dialer to make
that set
of tones...
Yes thats a red box...
worked quite well until they rigged the phones to mute the mic
until money was deposited.
All COCOT phones. Local telephone company phones I'm not sure....
And now it is all done as digital signaling out of
the voice-frequency range.
Which is why the blue box stopped working.
Steve WD8DAS
