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From: rees@pisa.ifs.umich.edu (Jim Rees)
Newsgroups: comp.dcom.telecom
Subject: Re: Touch-Tone Specifications
Message-ID: <15966@accuvax.nwu.edu>
Date: 10 Jan 91 18:49:35 GMT
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X-Telecom-Digest: Volume 11, Issue 24, Message 4 of 9


In article <15893@accuvax.nwu.edu>, hpa@casbah.acns.nwu.edu (Peter
Anvin) writes:

> this applies to Sweden, and may or may not apply to the rest of
> Scandinavia ...

>5. Get a phone that supports all four RJ-11 wires (including black/yellow).
>   Swedish Televerket warns that a "pirate" (non-compliant) telephone may
>   not hang up properly, running up your bill long after you hung up.

I know of at least the following uses of the "second pair" (yellow/black):

 - 10 vac for the dial light in older Princess(tm) and Trimline(tm) phones.
 - Off-hook indication for key sets.
 - Ring voltage for party lines.
 - Ground on the yellow wire for shielded twisted pair.
 - Second line for two-line phones.

Which of these does the Swedish system expect/use?