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From: hardarso@cs.unc.edu (Kari Hardarson)
Newsgroups: comp.dcom.telecom
Subject: Re: Touch-Tone Specifications
Message-ID: <72161@bu.edu.bu.edu>
Date: 12 Jan 91 18:49:53 GMT
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X-Telecom-Digest: Volume 11, Issue 30, Message 8 of 10


The Icelandic PTT also uses the big four-prong plugs. (Big enough for
supplying electricity to a stove !). The 2nd pair is used to forward
the connection to another outlet. If an outlet is used, an internal
switch cuts the forward link and prevents other phones down the line
from being used. The switch is mechanical, i.e. when a phone is
plugged into the outlet, the switch opens. I guess they do it to
prevent the telephone line from being overloaded by too many
telephones. Doesn't make much sense these days, I should think, since
the newer telephones don't draw as much current as the older ones did.


Kari Hardarson    217 Jackson Circle    Chapel Hill, NC 27514