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

You may remember from my post about station block layout that I rescued a 1A2 KSU from work a while back. I got tired of it sort of leaning against the side of my desk with some 66 blocks on the floor beside it and decided that it was time that it went back on a wall where it belongs. I've taken a few pictures of what I've mounted so far and now I put it to you for comments.

At first, I thought I'd leave the backboard unpainted since the KSU came with a nice dark green backboard and I had the color-coded pre-fab models for the 66 blocks. However, since I've seen it all on the wall I think the unpainted 3/4" ply needs to be gray.

I plan to run the station cables out from below the station blocks and up the right side of the board into a chase that runs all the way to the attic in my house. The left-most block on the red backboard will be for the diode matrix made out of a 66B-50 block and clips from a 66M-50. It will be white instead of gray. I'm waiting for a yellow backboard to show up on eBay for the intercom, but in the meantime I think I'll use the lower right block on the blue backboard for that.

The space that all this is mounted in is under my foyer stairs in the basement. It's not a perfect space since the water heater, furnace, gas meter and main water shut-off all live under there, but the easy attic access makes it very appealing. Also, the block wall means no searching for studs to attach the backboard to. Unfortunately, I am pretty much limited to a 4'x6' wall area and I've already used 4'x4'.

The main ground point for the house is the main water pipe, so I'll probably ground to that as it is really convenient.

After I get the cabling in here nailed down (not literally) I've got to find myself some 66E3-25's to terminate in each room of the house. I never expected my roommates to actually want key phones! :rolleyes:

The 584C panel was made by Stromberg-Carlson around 1980-1981. It's wired a little different than the 584C panel I have by ITT. I opted to use the S-C 584C instead of the ITT one only because the S-C was steel and looked more solid. Pin 18 of slot 13 is hard wired to B Batt and pin 18 on all the other slots is left unconnected. There are some other peculiarities that I haven't quite nailed down as well. So even though there are 3 intercom cards in the KSU, I can only use one. There are 10 400E line cards, but I'm only using 4 since that is all the dial tone I can provide from my Asterisk server. The Melco intercom is from 1979, making it the oldest piece in the system (except for the stations, the oldest is dated 11-69). The power supply is by Elgin.

I think that pretty much covers it. If you've read this far congratulations. Go get something to drink. :toast:

You can get additional intercoms working if you want to. It may require a little wire wrapping, but it can be done.

Also 3&18 should be "A" Battery & Ground, not "B" - otherwise the ICMs will have a hum on them.

Sometimes battery was lifted from those pins to allow Music on Hold to be installed on line cards.

Good luck on your project!


Sam

I'd have put the red backboard on top and the blue one immediately below it. That's how they are designed to be used. That way, there would be no need for the white mushroom boards at all. With the current setup, there's no way for the KSU tails to reach the blocks on the red board without crossing the plane of the jumpers, a no-no.

Of course, there may not be enough room for you to have done it that way. With that being said, it still looks mighty fine. There's nothing more professional than an installation using factory backboards. I sure wish everyone did.

I would probably have mounted the Melco intercom perpendicular to the rack instead of parallel, but only to conserve space. There's nothing wrong with it being the way that it is.

Your 66E3 blocks won't be a problem, as I have answered your PM already. As for the yellow backboard, you may be better off with a blue one and a can of spray paint. Yellow backboards were rare even when they were fully in production.

It looks nice. Post some pics when it is wired up

Bacially what ED said. Red top left, Yellow next to it, blue below, no white needed in your picture. If there was room I mounted the key system above the Red board and brought the cables straight down to the blocks.

Ed, looks like you can still get the yellow ones.
https://www.emersonnetworkpower.com/EnergySystems/pdf/plant-accessories/OSPDS-154900.pdf

Oh, you can certainly still buy them. There are just minimum ordering quantities from most manufacturers. It's hard to find suppliers that maintain a large inventory of them, especially the ones designed for 1A2 installations.

I think your idea of a can of spray paint is a better one

Thanks for the input guys. After a bit of consideration, I've decided to get a third sheet of plywood and mount it below the other two. Then I'll put the KSU at the top with the red backboard below it and the blue below the red like Bill suggested. I think that's the way to go. I'm going to keep an eye out for a half-width board (any color) that can go to the right of the red one. I'll paint it yellow if I have to.

This improved layout will allow me a lot of room on the right and bottom of the wall to route my station cables.

Ed, the main reason I mounted the Melco flat like I did was to make it easy for me to read the installation instructions. Plus I had a lot of space to fill in.

-Tim

PM sent.