atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems 1a2 system

The 711B was donated to the engineering school back in the late 60's, and somehow found it's way to the station, where the station engineering department installed it, much to the annoyance of the telco (Pacific Telephone at the time).

The 711B was served directly by telco for many years, and was finally placed behind the campus PBX (NorTel SL-100) about 15 years ago, in order to take advantage of the school's bulk long distance rates, and extended local area dialing, and long distance access control and accounting.

The 711B was in service for about 15 years before Stanford installed the SL-100, before that the campus was served by Centrex, giving KZSU the distinction of being "Stanford's Oldest Independent Telephone Company"

The 711B had a few special hacks, including the ability of certain special extentions to connect to other extentions without battery present on the circuit, allowing for audio feeds to be setup thru the switch. There were bandwidth restriction due to the various transformers and coils in the circuit, but it worked.

There were about 100 extentions in service, out of 200 available. It has been downsized in the last few years to make room for a donated NorTel PBX, that has yet to be placed in service due to software issues.. I think they just removed a bunch of selectors, etc that were never used.

1890's technology, manufactured in the late 1950's, installed in the laste 1960's, and still in service in 2005. Hows that for longevity.

Currently, audio feeds on campus are patched directly on the main patchbay as dry pairs.

I've got plenty of 66E3 blocks to help keep your 1A2 ship-shape for sale!!!!!! CHEEP.

I should know this, but how is a 66E3 different than a standard 66E? I sure could have used those adaptors that provide 2 female 25 pair amphenol connectors from 1 25 pair feed. I believe theres a male connector in the middle and a female on each side.

The 711B was donated to the engineering school back in the late 60's, and somehow found it's way to the station, where the station engineering department installed it, much to the annoyance of the telco (Pacific Telephone at the time).

I think that's cool the step system is still working. That's neat how you can patch audio through the switch, although as you said the audio might not quite be 30-15khz. It was almost like those step COs had character back then, the dial tones & ringing signals varied with different offices, and even slight differences could be heard with the same "model" CO. I'd like to find history book about Central Offices & telephony development in general.

Yep..
The switch has been updated a bit over the years, for instance, there is a standalone module (teltone M-106?) that allows passcode protected access from the outside via a directly connected POTS line.

Special features include seizing ringing incoming CO lines from any phone in the system, paging, and monitoring of various audio busses, and I think it will do transfer of incoming CO lines to any extention as well..

For books, you want to look for the Bell System publications "The History of Science and Engineering in the Bell System". There is a whole series of them, now out of print, covering switching technology, transmission technology, etc..

For books, you want to look for the Bell System publications "The History of Science and Engineering in the Bell System"...

Thanks, I'll see if I can find that. One bit of history I have, on reel-reel tape is a call to information asking for the Bryant Pond Maine Post Office. The operator had me hold awhile, could hear her talking to others, then said "Dial 0 and ask for Ringdown 77". The year was 1982 and Bryant Pond was the only remaining "Cord Board" central office in the USA. I did make the call & before the Bryant Pond operator connected me she told the long distance operator "The Post Office is closed!" I think they went to a digital CO a few years later. They probably now even have DSL.

Ok. So i FINALLY went up north and now have the system in front of me. It is a 551c system wondering if anyone is still willing to help me put this together. Thanks

What is it you need to know? The lines are 3 pair each starting with the wh/bl. Buzzer leads are the yellow green, common bell is yellow slate. If memory serves the co lines are on the bottom. There will be others who can remember these things too. I've got some old manuals...somewhere!!... You'll need line cards and you'll need an intercom card, if you want intercom. I think most everything else is in the 551. You'll only have button and buzzers unless you add a dial intercom.

If you want old equipment how about the stromberg carlson that uses the 2 step relays. I still have some in use at the horse race tracks here in Maine.

Well, I still dont know how to hook up the bell for co ringing. I think i understand how to hook up the melco mc-9, to work with the buzzers in the phones.

If there is an interupter installed and you want a common bell come off the R RG lead to the yellow slate of the phone. If you only want it to ring one line, put the yellow slate of the set to the T&R of the line you want to ring. (Not the CO feed)