atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems My recent prize

No, that makes sense to me Ed. I just always hear you guys talk about the ITT stuff and wondered.

So are there different line cards as well, for rotary or TT?
I haven't had a chance yet to get into the manual other than skimming.

The line cards work for any type of dialing. The basic intercom cards were usually rotary dial only and a touch tone adapter needed to be added. Most intercom cards were for 9 or 10 stations. There were expansion cards that would expand the capacity to 19 stations or more. That might also be what you have.

CK-3641-1 Station ktu w/busy tone(3-sta per board)

CK-3642 Link card (Blue tab)

Ck-3643 Common ctr. no. 1 (green tab)

ck-3644 Common ctr. no. 2 (yellow tab)

ck-3645 Tone (Black tab)

ck-3646 Interrupter (Red tab)


ck-353 Detector (White tab)

ck-354 Translator (White tab)

Cards for K-36 ITT

Its a flaky system to work on, and cards are very sensitive.

BTW I reviewed you recent pictures and it is not a K36.

Back to the click, click, click on hold. You usually don't get that on a small system. You need hang a 2565 set on the end of 1000 feet of cable. Then the lamp & interrupter are very prevelent. No need for MOH, you knew somebody saw that light blinking.

Ain't that the truth. The larger systems that had loads of long cable runs definitely had the louder clicking when on hold.

We had similar ones like that made by AE and the equivilent made by NT. The only usefull thing you got there is the fiber glass cover I have 15 or more I use for growing flowers in. The rest of the stuff went for scrape metal.

Doing some reading in this book and they are cover 1A, 1A1, 1A2, and 6A. It doesn't tell me what the difference is or better yet, what do these numbers mean anyway?

tp,

Even though you use BIX, I'll give you the little bit of history I know on these.

Basically they are the same except ---
1A was "line powered" without lights, basic hold. Wire wound relays.
1A1 was powered but still basic --- ? lights and button ICM? Still relays?
1A2 We all know 1A2 --- bells and whistles. KTUs and other analog printed ckt cards.
6A more bells and whistles.

Size and vintage --- but remember the Model T came before the Model A Ford cars.
:rofl:

This is by memory and that ain't too good anymore. :bang:

OK, I am not old enough to know for sure, but I will take a stab at it. The numbers don't mean anything, they were just given by the original manufacturer (Western Electric) as nomenclature.

1A: The very first key systems using central control equipment; fixed in configuration and difficult to modify. All components were hard-wired together; no cards of any kind.

1A1: The improved version of the 1A that was a bit more modular in design. KTUs (Key Telephone Units) were individual rack-mounted circuit modules that consisted of exposed relays and components. On the back side, there were screw terminal fields where installers interconnected them for the desired systems configuration. Despite it's perceived antiquity, it still had KTUs to permit Touch Tone intercom services. It was phased out in the late 1960's in favor of 1A2.

1A2: The last version, though it had many improvements along the way. This version had most features, such as lines and intercom services on cards. Most card slots were hard wired for specific functions, but there were usually flexible slots that allowed multi-functional use. These slots had options that had to be activated through physical wire strapping.

The final 1A2 equipment was the 620 panel system. It consisted of modular panels that could be stacked side-by-side for any configuration. There was a Molex-type connector on a cord from each panel that mated with modular power supplies. Typically, the power supplies were mounted up high on the wall. There were two types of power supplies; four-panel and ten-panel. The panels were then mounted below them. Any panel could plug into any connector on the power supply. The 620 series panels were primarily for line cards and had pink-colored 66 fields. The 640 series panels were for intercom and special circuits such as tie lines or music on hold. They had a yellow-colored 66 field. These panels were also designed to line up perfectly with today's colored backboards for 66 blocks. The manufacturing of 1A2 equipment faded away in the early to mid 1990's as demand dropped.

6A: This was an advanced intercom system during the 1A1 era (and into the 1A2 era). It also consisted of rack mounted KTUs that were hard wired together. This intercom was unique in that it offered two talk paths. This meant that more than two parties could use the intercom system at a time. The first party would dial a station. When the called party answered, they were transferred away from the common control equipment into what became a private talk path. This freed up the common control equipment for another set of users to make a call. The second call was not private though, meaning that anyone who picked up on the intercom line could barge in. Line keys for the intercom system lit when in use, so it was optional if someone wanted to be courteous.

Some of the "advanced" features of the 6A were:

Two-link (path) operation;

Flashing intercom button lamp when called;

Intermittent ringing or buzzing instead of single burst;

Flexible expansion by adding KTUs up to 91 stations.


This ends today's class.

We had a WE 711B SxS PBX at a college radio station I worked at, with several 584 panels.

We had battery at both -48 and +24vdc, and all lamps, and 2 out of the 3 interrupters were 24vdc.
We could run the entire air chain, emergency lighting, and studio equipment off of an inverter from the -48 battery bank in the event of a power failure, in addition to the phone system.

We also used 24vdc for various amplifier modules, control switching, etc..