W.E. 544 B

[Babybearjs]

I pulled up my copy of the BSP on the 544 phone and noticed the printing date.... 1970... I was surprised as I thought these phones were already extinct by then.... does anyone know really how long the 544 was in use? I thought the phone had been pulled out of service by 1965 and replaced by the 564.

[unbeldi]

Bell System telephones were generally designed for a 20-year service life.  While new installations would certainly get the new successor equipment, technicians still had to service older equipment and BSPs had to cover everything that a workman would typically encounter in the field.

For example, even E1 handsets were still covered in the BSPs of the 1950s.

[poplar1]

John Rains, who started working for Southern Bell as a dedicated tech assigned to the Georgia Capitol in 1956, told me that the 540- series sets never had Amphenol plugs. This could mean that they were "Manufacture Discontinued" by the early 60s. There were still some in use in the early 90s in the State of GA Health Building.

By the way, John's first assignment in 1956 was to install 755A PBXs throughout the 1899 Capitol Bldg. After working for Southern Bell/AT&T for 30 years, he hired on at the State of GA Telecommunications Dept. as a lead tech, working out of the same work center in the Revenue Bldg. where he had started in 1956.

[Babybearjs]

Back in the day.....1950's... all telephones were hard wired. including key sets. when did the amphenol connectors get started? I am curious about that as the cord on the 544B did not have a connector on it... it was all spade terminals.

[unbeldi]

Back in the day.....1950's... all telephones were hard wired. including key sets. when did the amphenol connectors get started? I am curious about that as the cord on the 544B did not have a connector on it... it was all spade terminals.

Not all telephones were hard-wired. Since the 1920s, customers could request a portable installation, so that a set could be moved to a patio, or within a large residence. Already in ca. 1930/1 the 283B four-prong plugs were created for portable anti-sidetone telephones.

The 50-pin Amphenol connectors became prominent with the introduction of the 1A2 system in 1964, but I think they were used already for some applications a few years earlier. I don't have an exact year off-hand, but I think I may have found a reference of ca. 1961.  1A2 modularized and miniaturized key systems and installation was greatly simplified.

[poplar1]

John, check as he various BSP issues for 564s and see if you can narrow down the approx. date for amphenol plug-ended cords.

Alsoo, the color code for the mounting cord changed from red, green, yellow, black, etc., to blue-white, white-blue, orange-white, etc.

And the lamp leads, instead of being grouped together, were associated with each line so that every 3rd pair was for the lamps

With the introduction of mini blocks (66M1-50), the station cables were punched down permanently on blue backboards,and F cross-connect wire (3-pair) was used between the red boards (feed from 1A2 key equipments) and the blue boards (station cables). The old method, even after the introduction of the larger 66B blocks, required terminating the actual cable pairs at the multiple blocks.

When cables were not numbered on the equipment room end, you could put a tone on a vacant pair on the station end, but
Martin Johns taught me that it was easier to trace out the intercom signal pair (usually yellow-green) for the intercom number assigned to the station you were working on. That's because each station had a unique intercom number. However, it was much more difficult to follow the found pair when all the cables were terminated directly on the multiple blocks, rather than cross-connected.

[unbeldi]

I can tell you that the earliest plug-ended cord I have recorded was a D34B III-64.
This is also the year that they were added to the 540/560 BSP.
For the 540s the cord was D24D.
These cord types were used for maintenance only, however.
At least some sets on which the mounting cord was changed were stamped  E/W D34B CORD:

[poplar1]

At one time I had a lot of 564HD+ sets that had black mounting cords with amphenol plugs. I believe that some of these cords may have had the original spade tip cords, but that the plugs had been added later, rather than replacing the entire cord. Some of these cords had the old color code, but I don't recall the date on the cord so can't know for sure whether the cords were replaced, or just converted to plug-type.

What year did the color change for the mounting cord conductors happen?

[podor]

Are the dates for amphenol connectors the same for the 565hd? I have an all 1/62 with a D50C stamped '61 with the connector. I also have a 564hd that is all 6/63 except for the D34B which is stamped '64.