atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems What are WE 15D, 6C and 17B KTUs?

I haven't been able to locate BSPs for WE KTUs 15D, 6C and 17B (1A1 key system vintage). Any help what they were used for would be appreciated.

Also, I'm looking for a latching relay that I can have operated by a converted pick up key on a 6 button keyset, using the A-Lead voltage. Any suggestions where to find are most appreciated!

I often used a 237B KTU for this purpose. Even though it was intended to be used for tying CO lines together (conferencing), it offered the latching relay needed so that a non-locking key would control it. Not to mention, it had lots of relay contacts so that it could be used for just about anything.

Thanks, great idea! I'm setting up a search eBay to let me know when one is available! Jim

I should be able to put together the BSPs for those KTUs.

The 15D was a ring up relay. As i recall, It sensed incoming ring from the CO and applied locally provided lamp battery to lamps and locally provided generator to audible units.

The 6B/C was a busy lamp unit. It went in series with a telephone line and when the phone went off hook it gave you a closure to light a lamp.

The 17B was a DPDT relay.

I'm pretty sure I have a17B or two. No 15Ds. Maybe a 6C. I have to look.


Sam

I have a couple of17Bs, a 17A and a NE 6B. If you're interested, let me know.

I've got the BSPs PDFed. Let me know if you want them. PM me with an email address I can send them to.

Sam

BSP 518-112-421

Thank you Arthur!

Sam

Hi Sam,

Earlier I mentioned I was looking for a way to provide A-Lead control for single lines sets that did not have an option to rewire. I've tried a few kinds of relays (from Sandman's company), but usually I get a lot of false signals when the CO is ringing. I am hoping for an easy solution where I can run all the T&R single line sets from one relay, that will give the A-Lead control when one goes off-hook.

You gave me some advise about a 6B/C busy lamp unit. "It went in series with a telephone line and when the phone went off hook it gave you a closure to light a lamp." You mentioned you might have a spare. If you think this relay could control about 6 single line sets (all short distances from the KSU), I would love to try. I haven't had any luck searching for this KTU on eBay, and you mentioned you might have one.

You advise on how to work this would be most appreciated!

Thanks,
Jim

Please read the BSP referenced in my previous message. Look at Fig 11 which is the 18-type KTU. Note that it uses two relays. The Sandman, Melco, and other so-called A-lead adapters have one relay, and fall short of the WE design. If you use an 18D or 18E KTU you will get proper operation.

You need to wire the T & R of the single-line phones AHEAD OF the line card, directly on the CO T & R, so that there is loop current available to knock down the HOLD condition. 400-type cards exclude the line (and therefore any loop current) from the STA T & R when on HOLD, preventing the series relay in the 18D KTU from operating.

The 18D/E is the proper relay for true lead control (except of course, modifying the sets and using 4 conductor line cords - that's the right way to do it!)

A 6B/C will light the lamp on the key set when the associated Single Line set goes off hook, but it won't break hold (As I recall).

I do NOT have any 18D/E relays (someone else might). I believe I might still have a 6B/C unit for sale.

PM me if you're interested.

Sam