sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems 1A key question and introduction

I just found this forum a few days ago in search of some answers about an old WE key system.

First let me introduce myself. My name is Steve and I have been collecting telephones (along with old radios and televisions) for about 30 years. Currently I have about 140 phones. I have an ITT 601 key system hooked up in part of my house eventhough I only have one line. Of course I really don't need it but it is fun to have!

I have about 5 of the WE 400 series phones that I believe work on a 1A system. I would like to hook up a few of these just for fun also. I have several 1A KTUs and I connected them to a key phone according to schematics that I found on various sites on the web. The problem is, the hold feature does not work. When I hit the hold button the hold relay does not energize an I lose the line connection. Is the KTU the only thing needed for the basic hold function? I would appreciate any help or directions to a place to look for help.

I am posting this here as the 1A set-up is a precursor to the 1A2 system but please feel free to move this post if it is in the wrong place.

Thank you,
Steve

Hi, Steve and welcome aboard.

I'm up for a challenge. If you can e-mail me the schematics for the 400 series phones, I am confident that I can help you with this.

Hi Ed:

Thank you! Here is the web site that has the schematics for the 400 series phones.

https://www.telephonecollectors.org/DocumentLibrary/BSPs/502Division/502-435-400.pdf

The set I was using is a 440. I also tried a 460.

Here is the site with the 1A KTU schematic:

https://telephonecollectors.org/library/weco/1aktu.pdf

Steve

Ed:

That is a long file to sort through in the first site I posted so if you prefer I can email just the schematic as you requested.

Steve

Steve, I'll take a look at the schematics tomorrow and see what I can figure out for you.

Ed -

Give a yell if you need a hand. I haven't worked on 1A in almost 30 years, but I probably remember it better then what I had for breakfast.

Sam

As a thought try reversing the balance & hold leads at the 1a unit.

Steve:

By following Table A on page 4, you should be fine. Aside from some wire color changes, the phone is functionally-equivalent to a 564 for the most part.

Note that each line has a tip, ring, B, H, lamp ground and lamp (the traditional 3 pair arrangement used with 1A2). The major change is that H and B are now referred to as A and A1. Like with 1A2, you only need one lamp ground (LG) and one A1 (B) lead to the phone. The lamp grounds are already common in your set, so you are already well on the way. Here are the line cord conductor color translations:

Line 1:

Tip = green (white/blue today)
Ring = red (blue/white today)
A = black (white/orange today)
A1= yellow (orange/white today)
LG = slate/black (white/green today)
L = slate/yellow (green/white today)

Line 2:

Tip = white (white/brown today)
Ring = blue (brown/white today)
A= brown/green (white/slate today)
L= slate/blue (blue/red today)

Line 3:

Tip = brown/black (red/orange today)
Ring = brown/blue (orange/red today)
A = brown/white (red/green today)
L = slate/white (brown/red today)

Refer to fig. 4 on page 7 for the remaining line keys.

Some of the old pros may want to double-check my assumptions here.

Thank you all for your willingness to help!

Jim: I reversed the B and H and even the tip and ring leads and it still does not hold. When I push the hold key the relay energizes but then releases so it does not hold the line.

Ed: Just to clarify, I don't want to connect the 440 phone to my 1A2 system but will if all else fails. Currently I am trying to connect it to a 1A KTU. Based on what I read I do not need a power supply for that KTU if I do not have lamp circuits but I don't know for sure.

Steve

I don't see how it can hold if there's no power supply. Something has to run to keep it on hold.