Subject: From: Date:

Panasonic Page Out herronf.us.ibm.com Tue, 15 Aug 2000 10:24:30 -0400

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I have the Panasonic Phone System.  I have speakers through out house for
ECS to speak caller id announcements etc.  Normally these speakers playing
music or TV.  ECS works great.  The Panasonic phone assumes you have
dedicated speakers and amp always on.  When you page there is a 618HZ tone
output on the page port, for about 2 seconds.
I built a Phase Locked Loop circuit using a 567 IC to detect this tone.
This is connected to Dig In on ECS who picks the relays to connect speakers
for paging.  The problem I am having is the phase lock loop is drifting off
the set frequency.  I have changed the 567 once, no help.  Anyone got a
better idea to detect a tone??  Other than have ECS announce every week;
"Frank adjust the FFLL"  Thanks.

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