Hi Ed, Bill,
Much thanks for your comments -- I've watched this board for the last few years, and I know you guys are the experts -- I'll make corrections.
Ed: Fixed, I think. I've corrected the T1/R1 stuff to use more precise references to the BSP signal names.
The Com Key manual's table is a little confusing to the layman; it shows 1+26 as "T(1)" and "R(1)", and pins 49+24 are "T1" and "R1". My table omitted the parens because they seemed to be used inconsistently (some had parens, "T(#)", and some didn't, "CA#").
Looking closely, it seems the parens were used only on the 1A2 style names (T/R/A/L), but not for the new "Com Key specific" names (CA#,DSS#). So I take it this was some sort of subtle visual clue.
I've tried to make this clearer by adding a footnote to my table. I should probably also include a scan of the original BSP table, as my table was re-arranged in the connector's pin order (my preference) whereas the BSP manual shows them in the 66block order. Thanks for the clarification!
Bill:
(1) Oops, I did seem to have the wrong description for my illustration; that should be a 981, not a 28xx. Fixed.
But regarding there being no 8xx/28xx's in 416 systems, are you sure? Maybe I'm missing something; that seems to disagree with BSP 518-450-105 (entitled 4A COMMUNICATION SYSTEM/COMKEY 416) which shows 2836 and 837 phones as being 416 sets:
https://seriss.com/people/erco/comkey416/comkey-8xx.jpg https://seriss.com/people/erco/comkey416/comkey-28xx.jpg From what I gather between 518-450-105 (which covers 8xx/28xx) and 518-450-106 (which covers 9xx/29xx), the two are both 416 systems and compatible; one notable difference being the lamp field; the 8xx/28xx have the lamps "in" the buttons, and the 9xx/29xx have the more common config of the lamps along the left edge of the line buttons. But both are KSU-less and according to the BSP's, compatible with each other.
I do want to get this right, so thought I'd better double check. Am I wrong on this?
(2) Yes, I'll adjust those references to RJ21, which is I guess an ethernet standard that came a long later.
But I have to say, if you're searching for these connectors and cables, searching for RJ21 seems to yield the best results from parts distributors, that all describe them as RJ21 (probably because thats what most of their customers are using them for these days).
So I guess RJ21 being back compatible with the phone company wiring is a plus for those of us still working with old business phones!
I originally had references to AMP type; when I worked for a 1A2 phone vendor in the early 80's (V-Band Systems in NYC) as a draftsman, our wiring diagrams referred to these as "Amphenol type" connectors which I think is consistent with the BSP terminology.
I'll always remember my boss, Leonid, who with his thick russian accent, had a strange way of pronouncing "Amphenol", it was more like "ArrmffeegnooOoolll", his tongue really twisted around those syllables. Good old Leon.. where is he now. Was a fun guy, designed phones out of thick steel, so the stock brokers we sold them to could beat on them with the receivers without breaking them. (NYC stock brokers were always pretty stressed out guys)
I recall there were other vendors for these connectors besides AMP; ITT and a few others I can't recall now. Leon and a few other guys in drafting would have heated debates about which vendor had the better connector; some used thick plastics (phenolics?), some thin, some metal, some had bad tolerances causing them to fit loosely or wear out quickly.
Would it be correct to call these "25 pair Amphenol-type" connectors as phone company parlance, and to indicate if one were searching today for these connectors/cables, one would have better luck searching for "RJ21"? I take it RJ21 basically embraced the phone company's wiring standard.
(3) Right, I'd agree.
I was thinking of doing a circuit analysis of the Com Key phones.. are there actual schematics for these? ie. not just block diagrams, but actual circuit diagrams showing resistor values?
I figure a schematic would be useful for fixing old phones (for those of us that wire them wrong!) and to see what design techniques were used. It'd be a challenge though, as there are some unknowns, like those custom WE chips on the logic board. My guess is they /might/ have pin compatible commercial equivalents, but it's hard to know.. might have to guess on those.
