sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Intercom

Ive got a stack of rt 1900's. I was meaning to use them for something else like a 19 zone page or to unlock 19 doors. Maybe a model train enthusiast would like them. Think of the possibilities!!!

My 1a2 days are dim like a bad lamp. Help me.

Hmmm, DTMF control of 19 different track switches. The digital stuff they've got now can do that if you spend serious money. But, your idea has serious merit for those of us with little $ and adequate 1A2 smarts! John C.

I like Station Specialties' idea. I don't need hold on intercom. That's sounds like something I can easily do. Could someone please give instructions on how to do that? I don't mean to be a burden but I'm trying get as many features that I possibly can. Thanks a lot!

Correct me if I'm wrong, but I don't believe you could get hold on an intercom - unless (like the hot line I described) it ran through a 400 card.

I also don't believe that talk battery (-24vDC "A" Battery) on a 400 card will give you a working intercom. I seem to remember trying that about a hundred years ago (OK - Maybe 40) and not having much luck with it. as I recall, you needed 48V to get anything; but maybe some brands of 400 cards would work - I don't know.

What is being described is a manual intercom - I mentioned these at the top of the thread when I described three types of intercoms. It requires a 401 card to be installed in the KSU and one of the lines of the associated phones wired to that position.

To buzz another station, you installed buzzers in each set (usually on the Yellow/Orange Pair). One side of the buzzer (O/Y) was connected to battery (usually 10v or 18v AC depending on the buzzer) the other side (Y/O) was cross connected to the A lead of the button you were using as a signal.

To make it work, you would remove the locking screw from a button on the set (Say the 4th line). You would then xconnect from the Black/Blue wire of the signalling phone to the Yellow Orange wire of the signalled phone and vice versa.

You went off hook on the manual intercom (usually installed on line 5) then pressed the non locking button on line #4. Ground flowed from the A1 lead (Blue/Black) through the button contacts, out on the Black/ Blue wire through the cross connect to the Yellow/Orange Wire connected to one side of the buzzer. As the other side of the buzzer was connected to battery, this completed the circuit and the buzzer buzzed.

Just as an aside some people were vehement about a manual intercom being on line 4 and using line 5 for the signal. I've seen fist fights on the subject. I'm not sure why, but people were very particular about that.

Sam

I found this on eBay: would this be sufficient?

https://cgi.ebay.com/Western-Electr...40%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

Another thing, is the Northern Telecom Logic 6 compatible with the U.S. 1A2 setup?

Yes, If properly wired to the KSU. Have used these before.

Thanks!

There were two types of 401 cards, "A"s and "B"s. The "A"s needed "A" leads and the "B"s didn't. They also had a set of contact closures that you could use for- whatever.

Besides manual intercoms we would use them for button access to an overhead PA system and use the contact closure to mute the music.

That will work fine.

Sam

Gh christ.

If you have to correct intercom card it will put the line on hold. The end of discussion.


We are sending talk battery voltage to L2 after the card assuming he does not have the card. Button contacts to A and A1 are used as a signal. Does not matter you can still use the lamp closer on card if you don't need a light. That's a pisser. So what lights the light? A and A1 off hook?

What if you remove the a-lead and press the button? What happens?

Don't make this cave man stuff difficult because I'm a cave man.


Provide talk battery based on the power supply you have with the 1A2 key service unit.

Give this to the t@r of the line button common to both sets. This is done without a tr19 or type melco.

Then.. Make a doorbell out of an unused button and steal the signal b bat from power from the 551 or what power you have available.

Often you just need a little common sense.

Lights hold and relay and talk battery.. We can substitute the line button for other needs.


This is the intercom he needs to build.