Hi everyone,

I have a WECO 551C KSU with an external Tone Commander rotary/TT intercom, its all set up and working fine. I'm currently using 10VAC buzzers for intercom audible in the 6 button sets and in a couple 2500's (that I added 10VAC buzzers to the yellow/black pair and I use the 2500's for intercom only). The 551C has a ring generator (currently not used).

So in the workshop and the garage, the buzzers are not loud enough to hear with all the background noise, so I aim to hook up a ringer (bell) to these 2 stations. What is the best way to send ring voltage on intercom contact closure...

(1) Put a 10VAC relay on the contact output of the Tone Commander, and then run the ring generator thru the contacts on the 10VAC relay?

(2) Discontinue all use of 10VAC for the Tone Commmander input and use ring generator as direct input to the Tone Commander audible? (Of course I will have to discontinue all use of 10VAC buzzers in all stations).

(3) If I do (2), can I send the ring generator output from the Tone Commander down to the tip/ring on the 2500's to use the ringer (bell) of the 2500's (instead of using the buzzer)? If I do this will this damage the A-Battery circuit (from the 551C) that I'm using for talk power on the intercom circuit? And of course, what happens to the ear of the poor 2500/2565 user when the phone is off hook and someone else dials an intercom station? I'd like your opinion if this option (3) is doable, a nonsense case, or just a real bad idea to be avoided at all cost.

Thanks, -Stryder

If you don't need the ring generator for the common bell than I'd go with #2. You can't send the ring voltage down tip and ring when you're using the talk battery, of that I'm pretty sure. If I'm wrong about that someone will correct me, I do think you'd blow a fuse before you ever hurt the filtered battery though. Been a long time since I use 105 volts out of a tone commander so I really don't remember, the wiring scheme is on the side so that should help you.

Bill's right. #2 will work best, especially since you already have the ring generator. You are right about the 2500's though; you can't run ringing across Tip and Ring for the intercom. You'll need to continue using the second pair and just wire it to the ringer in the set instead. The connections are as follows:

Black: Goes to black ringer lead on any blind terminal;
Yellow: Goes to red ringer lead on any blind terminal;

Make sure that the slate/red and slate ringer leads (if present) are connected to terminals A and K on the phone's network.

There's nothing wrong with connecting ring voltage to the RN and RG inputs on a Tone Commander intercom; they are made to permit this.

Also, remember that tip and ring of all intercom stations come back to a common tip-ring of the intercom, so if you tried this, a call to one station would have the potential to ring all 2500's connected this way.

As for the loud ringing when the phone is off-hook in use, there is a set of switch hook contacts that can be rewired to disable the ringing on most 2500 sets when off-hook.

Of course, you could keep it simple and buy loud ringers that work on 10-12 volts AC in the loud area.

I like your idea of the 10 volt ac bells, wish I'd thought of that.

First he needs the ring generator if he wants selective ringing on a 551. What I would do is make two spare buttons on a 6btn to ring the two stations if they are free. Kinda like a speed dial.

Keep the Tone commander for the SLT. Like Ed said you can Have intercom ring or intercom buzz. But if you choose to have Intercom Ring and selective ringing You will find it much easier to use the ring generator as the input to the rt1900. The common audible input would be much more of a hassle to achieve both intercom ring and common audible. Just my thought's but I would like to know a bit more.. I like the combination of using both the ring generator and common audible idea. Yes you can send the the ringing though the RT for intercom ring

But don't try to take RCRG on a common and send it to the rt 1900 for intercom. This is when the ring generator is needed.

Ed's idea of the 10v bells solves all the problems, in my opinion.

Yes and no, He has the 105 ring generator so wire it
and change leads in the set. No other equipment or relays would be needed. He just wants a few SLT to ring on intercom.. Remember intercom ring or intercom BUZZ? When you need a ring generator. Dial Buzz some station's and Dial Ring others. Easy

Ed A to K and K to A remove the condenser

Nope don't remember that, but it has been a long time. I only remember doing either or not both. Anyway what could be easier than going to the hardware store and getting a couple of 10v bells and just mount them by the connecting block? He's already using the black/yellow for the buzzers. I'm sure there's more than one solution.

To talk about how I would give this user ringing to station and buzz back... can happen with a 551 with ring generator and rt1900. I have wired a few to do this. You can never learn enough about 1A2 and it's possibilities. One can never learn enough about the given concept electrical ideas an old one's in itself being part of a rt 1900 era. Why not dial and turn on the lights
or open the garage door? After all there 19 relay paths.

RT36 even better.

The new RT 96000 microwave tone commander relay. On sale now! With remote notification to eject.

Some days I think they used just a RT 36 to land on the moon.

IA2 is a pain in the ass but you can build accommodations with needs. First of all going to the hardware store to get some 10v bells at what cycle?

With a rt 1900 he could dial and close a contact with conjunction of another relay. We are looking at 17 cycles and not ac of 60 or even through a transformer,

Charlie, I think the original poster's complaint was the buzzer signaling on two sets in the loud shop area. The buzzers are already running on 10 volts AC at 60 cycles. A regular bell like those used in elementary school science class experiments would work on 10VAC, 60 cycles with no problem.

Pretty quick and easy solution for just a few bucks. The existing buzzers in quieter areas can be left in place and the common audible ringing can also be left as-is.

I like your idea of controlling garage doors, etc. with 1A2 intercoms, in fact I used to do that with my system at home. Very handy!

What is an rt 1900?

Hi Bill, Ed and Charlie,

Thanks for all your suggestions.

Ed does make a good point that the main complaint was not being able to hear the buzzers in a couple locations. You have all offered several good options.

Charlie> Remember intercom ring or intercom BUZZ?
Bill> Nope don't remember that, but it has been a long time. I only remember doing either or not both.

Doing both is an ineresting idea. I'm not sure I can do ring on intercom station A and buzz on station B since the Tone Commander is indeed a RT-3600,,, the audible input shares a common ground with one side of all 36 station relay contacts. If each contact had 2 conductors coming out thru the AMP connector (to the 66 block), then I could do both by selecting which input (10VAC or 105VAC) to send to each intercom contact.

I don't understand the "A to K and K to A remove the condenser", so maybe that's why I don't get it yet.

Also, the ring generator is not currently in use since I'm not using common audible on the 551C yet. My CO lines ring bells directly in a couple sets. I would think that if I did hook up the ring generator to the CA, I could also send it to the audible input on the Tone Commander as well.

You are also right that at some point I will also hook up a couple intercom contacts to garage doors, so keeping the 10VAC on the Tone Commander likely gives me the most options for non-phone signaling (with an external relay).

Thanks, -Stryder

An external rotary or tone (RT) intercom unit mfg by Tone Commander, provides signaling to 19 stations. The RT3600 is the big brother for 36 intercom stations. I think (guess) the 00 (hundred) on the end of RT1900 is just marketing hype. RT-1900 sounds more powerful than Melco's RC-19 ;-)

-Stryder

Stryder:

Station Specialties is expressing the fact that there a zillion things that can be done with 1A2 equipment and he is right. It's just not a simple programming issue, nor just a phone system, but it requires that you roll up your shirt sleeves and do a lot more thinking than programming today's more modern systems.

There's not much that you can't do with 1A2, but it's not always easy. You have to be forward-thinking and plan your project around "what-if's" or "if-then" situations. It can be done, but you have to possess a lot of patience unless you have worked with it for years. No single book or Website teaches this system; you learn from the school of hard knocks.

You would need to start up a diode matrix to share intercom and common ringing. You probably don't want to get into that, but if you do, it can be done.

There's only one intercom unit that I can remember that offered two different voltage inputs to permit ringing and buzzers. Valcom made it, but I am not sure if they even make them anymore.

Condenser is another term for capacitor. There is one connected between terminals A and K on the network for ringer isolation. It really only needs to be bypassed if you decide to mess with a diode matrix in the future.

It appears that you have a good grasp of your situation, so for now it's great that you have something to work with. As always, feel free to check back when you are ready to move further into this.

viking and wheellock both used to make ringing adapters. viking has one using a contact closure. just add a 10v relay. or take a piezo , if loud enough, and add a diode bridge

or use a relay to turn a radio on and off.. Remember LOUD Klaxon horns?

Yes of course we had a Klaxon in the fire station on the single line phone (emergency RED Line). That one must have been connected to the tip/ring from the CO since we did not have a key system (KSU) at the fire station. (Acutally the fire stations preferred to have a bank of single line phones with neon ring lamps, no KSU to deal with if the power was out).

Speaking of the fire station (this was in the the 1970's), they had this wacky signaling system on the RED line for the fire alarm. The RED phones had an exclusion key in the hook. With the phone off hook, you pull up the exclusion key, and push this external button (which sent tip to ground). This would close several can relays also connected to the line in parallel (thoughout the town where the alarm sirens were located). Sending tip to ground would cause the CO to ring the line and close the can relays to set off the fire alarm. The only catch was that only one RED phone could be off hook or else the line would not ring.

The part I never figured out was what kept the can relays from closing when the RED line would ring normally for an incoming call? I'm guessing the can relays were connected ring to ground?

One diode in line (1/2 wave) or a (4-diode) full wave bridge?

That's the beauty of the older systems. You could rig up tricky stuff for unique applications. No need to consult with software engineers halfway around the world.

Sounds to me like the can relays were just 24 volt ones wired through independent circuits associated with the exclusion keys and buttons. No tip and ring with relation to the operation of the coil. This setup would require external power though, to operate the relays. Did they maintain a small bank of dry cells (that's what they called batteries back in those days) for this purpose during a power outage?

The exclusion key was really just a three-pole, double throw switch and you could use if for any function you wanted. I frequently used them to add intercom to six button sets that already had all buttons used.

From what I gather, unless this key was pulled up, the special signaling didn't occur. The can relays were probably isolated from the red phone's control until the exclusion key was lifted. Of course, you had to lift the handset before you could even access the exclusion key anyway.

Tip to ground would be hard to use in this application since tip is supposed to be at or close to ground potential to begin with. It would be like touching the two ends of a piece of wire together. I imagine that this was part of a modified ground-start trunk circuit in the CO, where instead of returning dial tone upon ground, it activated the array of relays and ringers all over town.

There's my $4.95 worth.

Has anyone got a couple of the old AC operated key-system triggered Wheelock klaxons or loud bells. They'll trigger off 10vac and applies plain old 110vac to the NOISE-MAKER. Give Stryder a qoute on $. It'll do what he wants AND that's what it was originally designed for, LOUD ringer on 1A2 key system. (Go to the hardware store,hmmph) John C.