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Joined: May 2005
Posts: 167
I once worked at a place that had a huge problem with "glare". That is, someone picking up an outside line would get connected to an incoming call on a regular basis.

At a company meeting I suggested that they order ground-start lines and change the modules on the Merlin to 408GS cards to fix the problem. GS=GROUND START. They had 408LS = LOOP START cards.

Unfortunately, all the "phone guy" heard was "order ground-start lines" and the part about changing the modules on the Merlin was totally missed.

So, for at least a day, nobody could make any outgoing calls.

I asked the "phone guy" what happened and he didn't want to "talk about it". I already knew what happened.

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Joined: Dec 2003
Posts: 886
And that is the reason ground start lines are used.


Joined: May 2003
Posts: 2,876
e57 Offline
3-wire was also used for the "princess", and other phones with lights on them as well. Some had seperate transformers, some had the power from the CO.

Mark Heller
"Well - I oughta....." -Jackie Gleason
Joined: Dec 2003
Posts: 886
The Princess and Trimline phones all used plug-in transformers and they had to use 4 conductors which was "quad" or "JK" wiring. The red and green were tip and ring, the black and yellow were 10VAC from the transformer.

I believe later on electroluminescent keypads were introduced that did away with the incandescent lamp and the need for a transformer. These used only the tip and ring deriving power from the CO battery voltage.

So no, the yellow was not used after party ringing was done away with as far as I know.


Joined: Oct 2003
Posts: 156
All you have to do is find the talk pair at the dmarc with a butt set or phone. Then homerun each jack from that point. If using CAT5 use the Blue/Wht pair, and connect to the RED/GREEN on a RJ-11 jack

Joined: Jan 2005
Posts: 5,390
Likes: 1
Cat Servant
I appreciate all the advice ... this is on my 'weekend list.'

Joined: Aug 2001
Posts: 7,520
The yellow wire on old party line service also served a secondary purpose in some cases. As well as providing the bell ground for split ringing, on some exchanges the equipment would test the resistance to ground before completing a toll call in order to identify the calling party. The ringer coils on each phone were wired slightly differently for each party to allow this to work.

Here in the U.K. we had ground-start on our two-way party lines. Because all calls (local or otherwise) were metered, the exchange needed to determine which was the originating party in all cases, and provided two separate line circuits.

A simple relay set added to party lines then connected the line to one or the other normal line circuits depending upon which side of the line was grounded to start the call. Party line phones actually had a button on top which you had to press to get dialtone.

By the way, I was looking through BellSouth's website for something the other day, and it seems that somewhere within its territory there are still some 8-way party lines in use!

Joined: Dec 2003
Posts: 886
I don't know if I still have any of the old Automatic Electric ordering information around. As I remember there were a number of ringer options available when ordering phones. There was straight line (not frequency selective) and frequency selective that would ring at only certain ring frequencies. There were also those with taps as you talk about. Ed could probably remember what that system is called, I would have to look it up.

So with all those options you can see how they can do 8 subscriber party lines.


Joined: Nov 2002
Posts: 456
Around here, there were three to five customers on a party line. Around 1980 they went to private lines.

For quite a while, a three wire cable fed the phone, and it is still in the wall, then along the basment works. All replaced with Cat3 cable.

Joined: Jul 2004
Posts: 9,827
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Way back in the olden Ma Bell days the "phone man legend" scam was you could order 16 party service and be pretty sure you would still have the line to yourself since nobody else would order it. I am not sure anyone ever tried it tho. It was supposed to be an option in the tarrif.

Greg Fretwell
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