sundance-communications.com/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems General thanks and Exbar security linecard question

Hi guys,
I have been a lurker on this forum for about 18 months and I feel I need to say thank you for all the information you present here. I have always been a "phone guy" Since I got my first phone for my 6th birthday. The 1a2 fascination happened a few years later when I got a 565. Never could run it until many years later when I got a shoebox out of a motel that was being demolished.
At any rate that was all well over 30 years ago and finally, because of finding this group, I dug the equipment out of storage and have been working on setting it up properly. You guys helped motivate me and have provided invaluable assistance. So again, Thank you.

So for the first official question: I have 4 Exbar 4-007 security linecards that I want to replace my 400D cards with. I have looked high and low and cannot find any documentation on them especially for the "strapping" options which are actually DIP switches.
I don't suppose anyone has any documentation on these???
The security settings are a separate bank called PFC and the label states "secure only when PFC switch is OFF" so those are pretty self explanatory.

The other bank of 5 switches are labeled as follows (rather than "off" or "on"
#1 RS/BG
#2 RN/RB
#3 LD/SD
#4 NR/LR
#5 IR/DR
Any thoughts or direction would be appreciated.
Best,
Shawn

Dimension, are you sure you aren't speaking of San/Bar secure line cards? I've been working with 1A2 for decades and have never encountered the brand name "Exbar".

I don't have the documentation that you're seeking, but if my assumption is correct, maybe you're using the wrong brand name in your search? Just a question.

I've never heard of exbar either. If it is that brand, can you take a picture(s) of the card and post it?

As Ed said, there was a manufacturer Sanbar that manufactured 400 type cards for the government that were designed to prevent anyone from listening in.

Sam

Ed,
It actually is "Exbar"; Supposedly the story goes that when SanBar closed up some of the staff continued to manufacture similar security cards under the Exbar name. They were in Southern California and I would imagine with the defense contractors in the area it was probably a niche market. Exbar does appear on government approval procurement sheets (alongside SanBar) as approved security cards.The guy I got these from got them from a building in the LA/Orange County vicinity that was being demolished.
Here are some pics



They are decidedly modern construction. There is a code on the back that seems to indicate a 1994 manufacture date and V0 version
I have tested one and it seems to work fine but I dont have the phone lines hooked up to check ringthrough and all the other functions. It also has three LEDs in the lexan pull strip. One of them lit up when the line is off hook. Ill probably play with them a bit more this week...

Item description:

Isolation Devices
DEVICE TYPE: Line Disconnect
MANUFACTURER: Exbar Associates, Inc
(Not able to verify if company is still in business)
MODEL: 4-007
TRADE NAME: Not available
DESCRIPTION & USE: This telephone security line card replaces the standard line card in 1A2-type Key Service Units (KSUs). It automatically disconnects the speech path of a telephone from the outgoing telephone line. This card is approved only when the PFC (power failure cut-through) feature is switched OFF.
ORDER CODE: Not available
POINT OF CONTACT: Not available
TSG NUMBER: None
PRICE: $170
AS OF: June 1995
COMMENTS: None submitted


Found specs in an old RFP for secure telephony proposals.

Sounds like an an automatic exclusion.

Bill -

As I recall (always suspect these days) it was not automatic exclusion (at least the Sanbar model). Exactly what it was though, I can't recall. It was only a available to certain government facilities - none of which I ever worked on.

The sad thing is, I remember asking a friend (who had worked with them in overseas US embassies) about them and he briefly explained them to me. I seem to recall that I thought it was nothing I'd really run into very often and never pursued it.

For the life of me, I can't remember how it worked.

Call " The Home" and warm up my chair. I think it's almost time. :-(


Sam

Wait! Rereading Dave's post, it comes back to me. The card, after some action by the user (pushing the hold button?) disconnected T&R from the set so the set could not be used as a microphone (not sure how this could be done) to listen in to conversations going on in the room.

I'm not being completely clear, but it's slowly coming back.

Cancel the reservation at the home. ;-)

Sam

There was a manual, where you pulled up the exclusion key on the private phone and there was an automatic where if the private phone picked up all other phones tip and rings were open.

That's what I remember and my rememberer isn't what it use to be.

Bill -

The manual exclusion sets I remember. You brought T & R into that set first and then sent it out to the other sets on another pair. When you lifted the special switch hook "key" and left it up then it cut off DT to all other sets.

The Sanbar card ( as I recall - badly) shut off DT back in the closet so it didn't make it into the set. The idea seemed to be that DT went back to the CO which was under control of the local government who could use it as a "conduit" for tapping. I think the only way this worked was if a bug of some sort was introduced into the phone itself, but I'm not sure.

Sam