sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems What is a.... Teltone M-487 KTU/OPX?

I read where these were supposed to be able to supply A-Lead control from T&R stations only. I plugged one of these in, and it functions like a normal 400 series KTU. The single line set I have is connected to the T&R pair from the KTU, however it doesn't return A-Lead when off-hook. I tried both on/off settings for "Low change sensitivity (for under 700 OHM Loops)" with no change. Any ideas? Nothing came back when Googled. Thanks - [email protected]

Update... In my KSU, I have one WECO 400HK KTU installed for CO Line 1, and the Teltone M-487 installed for Line 2. When I go off-hook on a 6 button set for Line 1, the lamp lights for Line 2 after a few second delay; similarly, when I go on-hook, the lap goes out after a short delay. But wait, it gets more perplexing. When I turn on the 4A speakerphone on Line 1, Line 2 does not light! My goal is to find a simple way to provide A-Lead control for sets where I can't rewire to provide and where I don't have to provide individual line sensing relays for each 2-wire station. I read all the posts for these options, but thought the "rare" Teltone KTU might do it.

I'm pretty sure that the M-487 detects tip/ring usage ahead of the line card, not behind it. It was designed for use with off-premise stations that shared the same line.

Ed, you are correct.

So it was a remote hold device?

Sam

It is a remote "line in use" device. Yes, if you put a line on HOLD at one location, it indicates BUSY at the other location(s).

Thank you, Arthur.

Sam

Hi, thanks for the info. I tried connecting a standard 2 wire station set to the incoming TR, the same pair that feeds the incoming T&R for the 487 KTU. No A-Lead control results when I go off-hook. I'm trying to get A-Lead control from station sets that are on the same premise, same location as the KTU - Am I interpreting this right? The KTU is on a CO line - not a PL or OPX. The 487 KTU works fine for 1A2 sets it feeds. Thanks, Jim

Jim, keep in mind that 1A2 hardware was designed to operate with precise line voltages and signaling standards. Those are practically non-existent these days due to CLECs, pair gain equipment and fake dial tone. Unless you are working with a real phone line, it probably won't do what it is intended to do.

You are using the wrong device. You need an 18D KTU, or a Melco A-lead device, forget the number.