atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Music on hold for 620A2

Hey guys. Fixed the no ring problem on my 620A2. The 60HZ to 30HZ converter in the power supply was shot. I did a little shopping at the old phone company garage that I got the rest of my stuff from and found 2 more power supplies. One of them was beat up pretty bad cosmetically, but I found a larger and more analog version of the converter inside of it. I believe the part number was 113 and I think the one I replaced was a 117 or a 115. Bolt holes lined up though it was twice the size. Phones ring just fine now. Also found a nice distribution panel on the wall that I cleaned up to make the center of my "plug and play" design for the system. Still haven't punched down everything yet, but once you get one line going the rest are all the same. I'm planning the finished product to have 4 line cards, a jack in the distribution box for 4 RJ11 lines to plug in, and to have 5 female RJ21 jacks for whoever uses it to plug in 5 phones.

I found some of the CPC splitters you guys were talking about on my shopping trip too, but they were only 3 port so they aren't going to do what I want on this project.

One more fun thing I was thinking of adding if it's not too hard would be music on hold. Is it possible to do with 400D cards? I was reading in one of the posts that there is an issue with people being able to talk to each other when placed on hold if it's not done correctly. Any suggestions on how to make music on hold work?

Some pictures of the system so far. Pardon the mess on my bench. Lots of different projects going on at the same time.

https://drive.google.com/file/d/1XAcrESltOGGPve-zTeIQc-12mNWQr4f1/view?usp=sharing

https://drive.google.com/file/d/1h0CGlbIhGD2M-fTsGLAq_Zqrw09MD2fd/view?usp=sharing

What if your backboard looked like this? Of course you would need to make/special order short 25 pr. cables with adapters. I can't remember how many I have thrown away over the years.

It seems like this is what we used for music on hold.

https://www.telephonecollectors.inf...-receiver-for-music-on-hold-service/file

All of our customers were Federal Goverment entities so we didn't use them often.

Here is the diagram for the 400D Line Card

http://www.kadiak.org/tel/400d.jpg

Could be we used 4200a Line cards:

http://www.kadiak.org/tel/4200a.jpg

Sorry, but were talking 30 years ago...

Music on hold is a bit tricky. What you need is a MOH card. It isolates the lines from one another. It's not a simple plug and play device. The Western Electric version is a 20 pin, 4 inch card that requires a separately mounted card holder. The ITT version is an 18 pin four inch card, but you can't just plug it in. It also requires a separate card slot mounting. The ITT part number is 403 and the WECO number is 451B. I have a 451B card in a separate card cage. It's been awhile since I installed it, so I don't exactly remember what went into wiring it in. I think tip and ring go in and out of it for each line and a music source. I don't think it required any power source. I think it's completely passive. Someone with more experience will probably know the exact BSP. The WECO card could do 7 lines, and the ITT was 4 or 5 I think. DO NOT plug one of these cards into the KSU directly. The DC power will fry them.

Both cards are EXTREMELY hard to come by.

There is another, simpler method, but it's not as nice. The ITT 400E cards have pins for music on hold. You can just connect a music source to those, but this only works for one line. If you parallel two or more of these together, you'll get cross talk. Bad.

I've heard of people making a similar modification to 400D cards, but I don't know the specifics of how it's done.

The cards Dean is referring to are made by San-Bar. Same deal, I don't think (I could be wrong) you could just connect the same music source to all the cards. Same cross talk will occur. San-Bar also made a 4 inch card that was a little radio on a card and the music came out on two of the pins that you could cross wire to the corresponding pins on their line cards. Again, it wasn't a simple plug and play. I think the music came out on 3&18, which is normally wired for A battery. Plugging one of these cards into an unmodified card slot fried it instantly. You had to unwrap the leads from 3&18 and insulate them, then wrap new wires from there to the card(s) you wanted music on. I've never seen one of these in person so I could be completely full of it, but that's what I've gathered from guys who've been doing this longer than I have.

If I remember correctly, the SanBar 4200 cards had built in isolation transformers in them. ITT 400E or Sanbar 4000F did not. An ITT 403 card allowed for full isolation from each line.


Someone please correct me if I've misremembered.

Sam

I've seen the sanbar 4200 ones before, even one that sold not too long ago on eBay. Cool design looks like a little radio that plugs into a KTU slot. Guess they're not quite so plug and play. Think I'll skip the music on hold for now.

CPC design would be pretty cool, but they're really hard to find as far as I can tell. I did fine 2 on my shopping trip to the old phone company garage, but I don't think there are any more. I threw out alot of them when I was starting out too, even used 400D cards for target practice. Never got into the stuff until my company bough this old SNET garage a few months back.