sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems 20A4 power unit

I found this in the electrical closet of an old motel. I'm curious if anyone has any specs for it beyond the obvious ratings if the fuses printed on the front. Also, I'm curious what it would have been used for in that environment. The rooms were wired with 4 cond JKT, only tip & ring (green&red) were punched down on the block, and only A battery and ring battery had wiring on this power supply. The cable was cut 6 inches from the unit and any other apparatus was long since removed. There is no "office" in this motel, only 10 rooms. Definitely not wired for 1A2, and the adjoining house, which was the office, has no cabling running back to the motel. They are seperate buildings about 100 feet apart. From what I can tell, there's a 25 pair OSP cable running into the closet from the street. It's clipped off so no clues there. There are some more recent drops, a few runs of four pair from some newer NID's scotchloked onto some of the JKT to the rooms, but not all the rooms are connected. Most go to some of those 66 block type protectors, but anything that would have fed those is clipped. At the moment, there is NDT anywhere and it's all pretty much abandonded in place. Any thoughts?

One thing's for sure: Those were great multi-purpose power supplies. Since you say that only A battery and ring generator outputs were used, I can't imagine what they were using it for. My first thought was some kind of intercom system with pushbutton signaling, but since you say only one pair from the rooms was terminated, that pretty much rules out that idea.

The 1980 date of manufacture makes it even more confusing. I'm at a loss....

That was the first thing I thought of too, but it doesn't seem like the wiring would have supported it, even if they had used the yellow and black, there aren't enough leads unless it was used through some sort of relay board. Wake up calls or something, but again, no cables went from the house/office to the motel building. One thing is for sure. I'm glad I asked the new owner if I could remove it and take it home. It works perfectly.

Edit: What manufacture date would be less confusing? And why?

Because by the late 70s, Western Electric and the Bell companies were focusing more on pre-packaged electronic equipment, such as Dialog (6B) intercom, Comkey, Horizon and modular 600- series 1A2 panels. Their intention was to improve uniformity and leave less room for error (dumb it down).

For something to have been custom-engineered in those days would have almost been unheard of for a new installation. If one of their pre-packaged systems didn't do it, the customer usually didn't get it.

As those go that's practically brand new. I vote for an intercom as only talk battery and the ring supply was used. Could have been some 1A2 equipment to provide interrupted ring and a Teletone DTMF intercom unit at one time.

-Hal

A Battery and ring generator to me, mean a 4415 ring down circuit (or something similar) - a hotline circuit.

Realize, it might not have been a Bell System install. The power supply could have been abandoned (anywhere) and reused by an interconnect tech looking to save a few shekels....

Sam

It's tough to say, it looks like it had been there a long time. It had a solid gray ground wire on it, typical of telco installs. Most of the wiring around it looked to be of the same vintage, and for whatever its worth, it was mounted with round head slotted screws. Seemed very original to me. But what the heck do I know. Some kind of dial intercom makes sense to me. There was alot of missing equipment that should have been there. The original 25 pair OSP was clipped off pretty high, I assume there would have been some sort of demarc in there. The blocks the station cables were punched down on had clipped off leads that must have gone to something else between the block and demarc. Really hard to tell. The room had been stripped out pretty clean. I'm surprised the power supply was still hanging there, albeit crooked. It has a mounting plate with two tabs that catch in the keyhole slots in the PS. There are two screws that hold the PS to the back plate and one is missing, so the back plate was straight on the wall but the PS was hanging by the one screw at about a 45 degree angle.

Good find! You can power quite a bit off of a unit like this. I use a 20B2 to power my 584C panel.

I would love to find a deal on one of those big panels... A nice 13 line setup..... mmmmmmm..... doughnut....

What kind of equipment would have been required in those days for a simple motel type setup? You know, dial 0 for the front desk, dial a two digit room number for another room and 9 for an outgoing line type of thing? Figure, this place had/has ten rooms, probably had 2500 sets originally, possibly old enough to have had 500 sets in the early days, maybe message waiting lamps, but I kind of doubt that. Each room utilizes only one pair, so nothing fancy within the room. I'm kind of curious how this would have worked before the proliferation of electronics.