Centronics PBX Adapter

[Milamontagne]

Hi there. While doing a google search for the above, I came
across this site, Specifically, This URL:

http://www.tek-tips.com/viewthread.cfm?qid=1300647&page=1

My company has a very old analog PBX system, and the
telephones are dying out, one by one. Its gotten to the
point where we have to swap in a phone that only works slighty better then the one we took out

I have no experiance with PBX systems, however a rumor
was heard by the office personnel that an adapter to a
standard telephone/RJ-11 Connector(s)(And hence, into
a regular, non-PBX telephone) exists or existed before
the system was made obsolete, probabily cerca
1980-something

The PBX connector is a D-sub Centronics 25 or 50 pin. The
phones support 5 lines with a hold feature that works though the PBX exchange box itself.

The internal phone system only has two lines, as is thats all that is currently needed.

My questions are, Does an adapter for such a system exist?
I've found what appears to be the adapter from AllenTel
here:

http://www.allentel.com/page85.html

However, I dont see a method to use the Hold feature. I'm
presumeing that the hold button is wired into the PBX
exchange box, and putting the line into the hold state
is done inside the box, not at the telephone itself.

I afraid that at this point, i do not have a model number
of the PBX system itself. It appears to have been made by AT&T quite some time ago.

Any information on what im dealing with would be greatly
appreciated.

 

[mforrence]

As you know, most PBX systems use proprietary telephones. While you can make/buy and adapter to easily allow the physical connection of a non-pbx phone to an amphenol (centronics-like connector) connector, that is only one part of the puzzle. The other end of the cable is still connected to the pbx. You could bypass the PBX totally and just use two-line telephones - however you would lose any features that the pbx provided - mostly intercom. If you really only have two lines and a couple of phones, call in a local vendor and ask them the possibilities. You may be able to remove the pbx (I suspect it is really a key system, not a PBX - but that's another discussion) and use two-line phones.
Mike

 

[skip555]

I agree get a few quotes , you might be surprised at the low price

if money is a big issue ask about used/ refurb we sell a lot of used refurb systems

your not going to find a cheap "magic"adapter

 

[CBasicAsslember]

Hmmm ... 1980? Sounds like a 1A2 key system. Do the phones look like this?

 

[LeeMcCauslin]

For some of our smaller branches, we have had really good results with these RCA small business phones:

http://communications.rca.com/en-US/ModelDetail.html?MN=25414RE3&Cat=System+Communication

. They take POTS lines (Bypass your key system/PBX) and are aware of each other so you can transfer between stations, put calls on hold and a few other pretty basic phone functions. You could even get 2 more phone lines and pretty easily wire up to 16 stations. Some models have built in answering machines too. 1 cat5 cable will carry 4 lines to any wall plate and with a little planning you can have a fairly well simulated phone system.

You might even be able to sell your key system for enough to cover new phones and wiring. But I agree with the others that a coverter/connector of some kind is probably not available.

 

[phoneguy55]

Time for an upgarde. A small Partner ACS system or something along those lines will take you business into this century and you'll gain a bunch of features....

 

[Milamontagne]

To all that recommended an upgrade: Thankx, I'll be checking up on them each in a few days. The owner of the
company has gotten a few quotes, however, is quite reluctant
to upgrade due the work environment. The company does welding and fabrication, which for any electronic device can spell disaster due to the extremly high EMI. The system, if a total upgrade, would need to be warrentied expressly for that type of environment. The system in place
has lived as long as it has possibly due to it being a key
system. The only part of the system that has failed are
the phones themselves due to


The link:

http://www.customphones.com/item79449.ctlg

Looks almost identical to the phones that we have. Even if
an adapter cannot be found, if someone can post a schematic
for the system, I might be able to make one. Thankx for the
help in identifying what im dealing with. I'm currently looking around for info and will post anything I find.

If anyone has any further information, it would be greatly appreicated.

 

[skip555]

why not just buy some phones from the link ?

120 each isn't bad or try ebay

look for a local vendor who can support it

I have a pile of that stuff thats headed for the dumpster when
I clean the warehouse.

comdial made a key strip that allowed you to plug a standard phone in but use the buttons for line selection hold intercom etc

look for them on ebay or Evan on line

 

[SYQUEST]

Hi Milamontagne,

Western Electric/AT&T manufactured several different 1A2 KSUs. If you can give a description of the KSU, line capacity, interrupter type, etc. I might be able to identify it for you. The model numbers can be hard to find sometimes.

I probably have the BSPs on whatever KSU it is.

The adapter you are describing is the 153AM1 & 2 adapter. When being used in the 1A2 KTS, it would provide access to the first line only. The pins are wired to the pairs assigned to the first line appearance. When using it with a single line set like a 2500D, the 2500D has to be wired for "A" control lead for the lite function to work. There is NO hold key in this arrangement. The wiring is as follows:

Jack Lead Plug/Connector Pin Desig.
RED 1 1R
GREEN 26 1T
YELLOW 2 A1
BLACK 27 A
WHITE 25 X1
BLUE 50 X2

The 153AM1 has a 6-wire MODULAR JACK and the 153AM2 has a 4-wire MODULAR JACK.

Hope this helps!

....JIM....

 

[CBasicAsslember]

The company does welding and fabrication, which for any electronic device can spell disaster due to the extremly high EMI.

I have a customer that does steel fab on a pretty large scale. They in fact did some of the steel structure work for the Olympics in Atlanta. They had a 6x16 Norstar since the late 80's and we upgraded the KSU to a CICS this last year. EMI has never been a problem.