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Old 30th May 2019, 7:39 pm   #20
Join Date: Aug 2007
Location: Walsall Wood, Aldridge, Walsall, UK.
Posts: 1,309
Default Re: GPO/BT Call Progress Tones?


Another memory has come back to me on the subject of GPO/BT Call Progress Tones, and that was I'm sure the Pay Tone changed format from a continuous series of rapid pips to a single burst, about 2–3 s long, of fainter but even more rapid pips, then if money wasn't inserted promptly enough (within 2–3 s!) you got silence then the 400 Hz N.U. tone and had to replace the receiver and restart the call again!

Can any Member confirm the Pay Tone changed in spec recently? The current BT S.I.N. 350 no longer lists "Pay Tone", so I wonder if it's now been abolished from the PSTN?

Chris Williams
It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed!

Last edited by Chris55000; 30th May 2019 at 8:00 pm.
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