[sdiy] [Way OT] Distinctive ring

[Dave Manley]

mrmike wrote:
> Sorry for the vary off-topic post, but is anyone here familiar with 
> distinctive ring for telephones? This feature allows a single incoming 
> phone line to be addressed by multiple phone numbers, each with its own 
> ringtone.  I'm trying to figure out how to DIY a device that will 
> recognize and filter the rings.
> 
> Well, it's analog, and DIY anyway...

Modern phones use Caller ID for distinctive ringing. The calling phone 
number is sent between the ring bursts at the start of the call. 
http://en.wikipedia.org/wiki/Caller_id


-Dave

P.S. Further off topic - in the old days of party lines the mechanical 
ringers were resonant tuned to different frequencies.  Google decimonic 
or harmonic ringer.  The central office could then ring the phone in 
different houses by changing the ringing frequency.