atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems exclusion

I just picked up a super nice 565HD from '62. Numbers matching with the soft plastic body and bakelite G1 handset. The exclusion switch is installed, but doesn't seem to do anything. I know they can be wired for different functions, but how were they usually set up? Is there a BSP specific to the exclusion? The BSP for the set isn't specific enough for a novice like me.

Thanks!
Mike

I'll have to look for the BSP.

As I recall, exclusion switches were usually used for two things - privacy and intercom. For privacy, the particular dial tone was fed through the switch first and then out to other sets. Lifting the switch denied access to other people from listening in on the conversation.

For Intercom (and here I'm a little vague) lifting the switch gave you a "buttons up Intercom" - IOW, when you lifted the ES, if all your line keys were up you had the availability of an Intercom path.

I'm a little vague on that one, because if we needed that feature we just used Stromberg Carlson sets that came standard with it.

I'll try to get to the BSP tonight or tomorrow.

Sam

Sam, that is correct with regard to intercom. It basically gave you a "seventh" button on a six button set. The hold button's lamp was often used as an in-use indicator.

Ok, this is becoming a bit more clear. The exclusion would only be on one line, and that line would be passed on to the excluded set on 4 spare pairs (blue violet, orange violet)? If that's correct, the excluded set would need to be modified also?

No modification on the excluded set, but its source of Dial Tone came from the Excluding set.

IOW, instead of DT being common to all sets (coming out of the KSU on T1,R1, it came out of the output of the Exclusion key on the Excluding set. If the key was in normal state, DT was available to all other sets. If the EK was engaged, no DT would be available for ll the other sets.

Sam

Ed, that's it. I really only saw it on jobs we were replacing. S-C had it as a Standard feature on their 1800 (?) line of 6 button phones (mini call directors) and people that didn't want a K-10 took the SC sets.

If someone had 4 lines and an Intercom we would offer them the S-C sets for expansion purposes. The salesmen however, looking to sell all new sets wouldn't.

Sam

Just messing around, I hooked up a normal 500 set to the blue-violet pair through a 149b block. The exclusion provides and disconnects dial tone as expected. So, I'm assuming that the 2 pairs from the exclusion would substitute the original 2 pair coming from the KSU for the excluded sets? If so, how and where would it be done? Was the exclusion more for one or two sets, or would it be used for a whole building? Thanks again for the input.

Mike

Sure, you could exclude as many sets as you wish. This tip/ring just took the place of the tip/ring coming out of the line card. You could even have some sets excluded and others that are not.

If I'm following this right, only one set can realistically exclude all others since the T&R are coming from the manual exclusion key on that set. I remember reading where there was a 1A2 KTU (405?) for Automatic Exclusion where any set could exclude all others. While not a good comparison, in the ComKey 416s, there is a privacy relay board in every phone (optional feature), and a Privacy Release button on each set which needed to be operated to let others bridge on to the line. I thought about this feature for my home 1A2, but never located enough KTUs (I think one KTU was needed for each station) to try. Can anyone clarify?

The first system that had privacy that I ever saw was the old Tie "Grey Whales" - the 1030.

In the early- middle '70s ITT also produced 1A2 sets with privacy units. AIR, the unit (which was a small circuit board) went into each set that you wanted excluded. No special system was required, just install the unit in each set you wanted kept out of the conversation (unless allowed in). I'm not sure if you could find any of those units around anymore, but who knows?

Sam