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

Well, Excuuuuuuuuuuuuuuuuuuuse me!

Mostly just for listening to music through my laptop :P

Thanks to Uncle Arthur, I now have a 401A card installed in my shoebox and it is working!
My next question is: how do I get a buzzer working on the intercom key?

You need to assign a spare line key (converted for momentary signaling by removing the lock screw) or add a 551A key, on the side of the phone.

Then you need to move a couple of wires around in the set. You need SIG GRD to come into the set on the BRN/YEL lead. Then wire that to one side of the signal button. The other side of the button becomes a signal lead that, when grounded, looks for the 10Vac buzzer battery on the buzzer at the distant end.

In the other phone, the buzzer gets put on the OR/YEL pair. One side (the Orange lead) gets put on 10Vac buzzer supply. The other side is tied to the signal lead discussed above.

These connections are all done at the MDF using cross-connections. Use solid black for ground, solid red for buzzer battery.

Note that "SIG BAT" on a typical power unit is ambiguous, and is actually -24Vdc. You need an A-C supply of 10 Volts. On a 20B2 supply, there is a screw terminal for 10 Volts, that is independent of the 10Vac LAMP supply. In a shoebox, however, you access the 10Vac by adding a wire to the LAMP BATTERY supply ("LB") on the 66 block in the KSU, down at the bottom right side.

BSP for 565HK set

BSP for shoebox

BSP for buttons & buzzers

Thanks!
The 2 keysets I am working with are 2564.
On the first set, I have already unlocked the 6th key and when I press it, the lamp lights and I get talk battery. It currently has a buzzer on the yellow/green pair.

The second keyset already has a buzzer in it, also on the yellow/green pair, connected to a doorbell button at the top of the steps, and a separate transformer. I've already removed the screw on the 5th key for this set. I have to finish these cross connections and see if I get talk battery and light (I expect to)

Perhaps I will give my Uncle a ring one evening after work this week.

Jeff

I will report back!

You're getting ahead of yourself.

Put the screw back in the 6th key. It needs to stay locked down for talking. The light should come on and stay on for the duration of the call. You need another, separate, button, converted for non-locking, to do the signaling.

If you don't have a spare button, you need to add a 551A outside the set, or convert to a 830 set, or...

That's why we recommended that you use a Teltone dial selective intercom unit from the git go. It needs no extra button for signaling.