Look at this relic 149B adapter I found STILL IN SERVICE

[Banner1971]

I was moving and extending a special service line at a customer's premises and I came across an office full of these gems which made it pretty easy for me to do my job.

I was not able to figure out what they were when on site so I had to just use an ohmmeter and toner and figure it out. It seems I hooked the tip and ring up backwards but it doesn't matter for this application. It bugs me a little but not much. I followed the pattern on the wires already there, that is my excuse.

I connected into this one and one other that had already had two other pairs stolen for a fax machine and whatnot.

I like to learn about these quality relics of a bygone era. Can anybody tell me what the meaning of the terminals labelled BL, SG and V is, and the significance of the A1 line being available, how they come up with the numbering for the pairs that are available, why 3, 4, 5, and 6 go straight through and the others are broken out?

Here is the data sheet I found:

http://bellsystempractices.org/EarlerVersions/400-/461-/461-200-102-i04_1975-11-01.pdf#5

 

[jrgood0852]

Wow! I haven't seen one of these in about 25 years, but I'm almost possitive it is so you can use a single line phone (CV) with the speakerphone kit. You need the amphenol that connects to the 4 conductor line cord of the CV, too. Anyone else please give more info if you have it. Thanks.

Always look out for the next tech. because one day it will be you!

 

[SYQUEST]

The 149A or B adapter was designed for a variety of telephony uses. Primarily it provides access to leads or pairs needed for auxiliary stuff like lamps, buzzers, ringers, jacks, signaling keys, etc. used in the 1A, 1A1, and 1A2 KTS provisioned on a 25-pair cable over the years. The terminal designations were self-identified to those that installed this stuff at the time.
A1 = A1 return ground (DC) for the A1 relay of the 1A1 and 1A2 KTU line circuits.
BL = busy lamp, used for indicating a phone or device off-hook or in-use.
SG = signal ground, used for the return path of a buzzer circuit.
V = vacant, that terminal was a spare to be used for any purpose.

The breakout of certain leads and pairs had to do with specific equipment that could be added to a phone station, like a speakerphone set. If you get the BSPs for the 3A and 4A speakerphone systems and the 565 or 2565 series key sets and study the wiring and the line cord lead assignments you will notice certain leads are assigned for specific stuff like speakerphones, buzzers, busy lamp supervision, etc. The design of this was highly organized by Bell Labs during those eras when this stuff was manufactured and put in service, to make it easier to install special service arrangements at the phone station location.

Hope that helps!
....JIM....

 

[jrgood0852]

This site may have more info. Even if it doesn't, check it out. Very cool.......

http://www.telephonecollectors.info/index.php/browse/wiring-diagrams

Always look out for the next tech. because one day it will be you!