[VoIP] Channel Bank on Ebay [not mine] and E&M

[John Novack]

Steph Kerman wrote:
> I don't follow what you are describing.  By "amp" do you mean 25-pair 
> AMP/Amphenol connector or amplifier?  I don't know what a 66 style jack 
> is.  There was an RJ20-series interface that was like a 12-line "series" jack, with T&R in and T&R out for each of the 12 circuits.  I think that's the RJ-22 or perhaps 21.  But it requires the insertion of a jumper plug to restore continuity when the connectors are separated.  
> The apartment house door answering systems used in many cities use this 
> interface.
>
>   
Envision a 66 block with a 57 series 50 pin plug or connector ( not sure 
which ) on the side, but a special one that had built in contacts that 
once the mate was removed, the T&R were continued through to the, in 
this case, 1A2 key system.
When the mate was inserted T&R of each line went through the connecting 
equipment which detected loop current.
Not sure if it is in your copy of the 1997 Part 68, and was not in 
existance in the 1978 specs, but was specified in the 1980's
As I said, seldom seen or used, but was an option for multiple line ACD 
and ?? systems

WAY off topic for this list though.

John Novack

-- 
Dog is my co-pilot