What is this? Multiline Telephone w/ Weird Jack

[WesternElectricBen]

Hi,

I was looking through eBay, and I saw this phone. It looks like just a regular black multiline, until I looked at the jack, not the 25 pair jack, but something that looks like a 4 prong style.

It looks like a 4 prong, but it has a lot more than 4 prongs. My question is, is this rare, why were they used, or phased out?

I am not planning on buying this, but I thought this was interesting. Link: http://tinyurl.com/m7wyk7j

Ben

[TelePlay]

Discussed, somewhat, here:

http://www.classicrotaryphones.com/forum/index.php?topic=9060.msg97124#msg97124

[WesternElectricBen]

Discussed, somewhat, here:

http://www.classicrotaryphones.com/forum/index.php?topic=9060.msg97124#msg97124

Thanks, I must have forgotten about that topic, sense I contributed in it.

Ben

[poplar1]

Look at the desi strip: 355-1961 on line 1, 31 on line 2. (31 could be either a pbx line or the station number on intercom).

These portable 6-button phones with 2 lines were sometimes installed in large residences behind a 1A2 Key System:

6 pair plug could be for example:

3 pairs=Outside line: Tip, Ring; A, A1; Lamp Ground, Lamp.

0 pairs=Line ringer (connected directly to Tip and Ring of Line 1 inside set) would not require a separate pair.

3 pairs=Intercom: Tip Ring; Lamp Ground, Lamp; Buzzer (2 leads)

[DavePEI]

Thanks, I must have forgotten about that topic, sense I contributed in it.

Ben

That's ok, Ben. Its called old age 

Dave

[WesternElectricBen]

Thanks, I must have forgotten about that topic, sense I contributed in it.

Ben

That's ok, Ben. Its called old age 

Dave

Look at the desi strip: 355-1961 on line 1, 31 on line 2. (31 could be either a pbx line or the station number on intercom).

These portable 6-button phones with 2 lines were sometimes installed in large residences behind a 1A2 Key System:

6 pair plug could be for example:

3 pairs=Outside line: Tip, Ring; A, A1; Lamp Ground, Lamp.

0 pairs=Line ringer (connected directly to Tip and Ring of Line 1 inside set) would not require a separate pair.

3 pairs=Intercom: Tip Ring; Lamp Ground, Lamp; Buzzer (2 leads)

Oh, I see, thanks for the information!

Ben

[poplar1]

This is how this one is actually wired:
12-pin plug but only 5 pairs (10 conductors) in the mounting cord, so only 5 pairs available to be used.

Line 1: 3 pairs
Tip (1T), Ring (1R) , A (1A), A1, Lamp Ground, Lamp
Line Ringer: Black to 1T, Red to K, Jumper from A to 1R

Line 2: 2 pairs
Tip (2T),  Ring (2R), A (2A), Lamp.

Strap (piece of wire) from Lamp Ground of first line to Lamp Ground of second line.

(For 1A1 and 1A2 Key, there is always only one "A1" lead per phone, regardless of whether it is a 6-button, 10-, 12-, 18-, 20-, or 30-)

Since the buzzer in the set was missing, it may have been connected to the sixth pair of the inside wire at the wall. However, if the second line "31" was a PBX line, then there may have been an E1 line ringer on the wall.