Message-ID: <022501c16996$4f5a1880$a4e3adcb@p150>
From: "Dave Brown" <tractorb@ihug.co.nz>
To: rsgb_lf_group@blacksheep.org
References: <155.3badb82.291bfd5c@aol.com> <00aa01c16876$8416c940$09dc9384@ma.ultranet.com>
Subject: Re: LF: Re: Ringing Voltage on Telephone , boo-boo
Date: Sat, 10 Nov 2001 16:17:41 +1300
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Here in ZL the line voltage (nominally 50) is reversed behind the low freq
ringing as well- lotsa PBXs use the line reversal these days and not the
actual low freq ringing signal- makes for faster call answering. So in total
one has a total transverse voltage of 50 plus peak ringing to contend with-
in our case nominally 80 vac ringing gives a total of just over 160 volts.
Since the A leg is basically at or near dc ground potential thats as bad as
it gets-within a few volts- using locally ground referenced test gear.
73
Dave Brown, ZL3FJ
Christchurch
New Zealand

----- Original Message -----
From: John Andrews <w1tag@charter.net>
To: <rsgb_lf_group@blacksheep.org>
Sent: Friday, November 09, 2001 5:57 AM
Subject: Re: LF: Re: Ringing Voltage on Telephone , boo-boo


> Larry,
>
> I'm with John Davis on this one. The U.S. practice is 20 Hz for ringing --
> nothing at 1 kHz.
>
> John Andrews, W1TAG
>
> > Larry, I have done.  My statement was based on having checked it
> personally
> > on a number of Bell and non-Bell exchanges over the years.  As I said,
it
> may
> > be different in Canada, but here it's 20Hz.
>
>
>
>