[GreenKeys] M19 perforator punch question

[E.]

Being a 15/19 guy…

1 — the perforator is not powered by the loop - instead, it is powered by what would have been the 120VDC rectifier on the backside of the 19 table (takes a lot of amps to punch - a 1A rectifier is usually good).  You can test it by removing the keyboard and connecting alligator clip test leads from the rectifier, to the correct terminals on the keyboard (and of course with the correct polarity)… but be careful ‘cause that is a lot of juice to accidentally bump.

The switch on the TT - as mentioned before, powers the punch with the switch is down, turns it off when the switch is all the way up or allows you to see what you are punching on the printer, when set in the middle.  The AC power switch does not need to be on when it’s only set to punch (but on for the rest preferably).

2 — When you press a key, there is a bar that slides underneath the keyboard, to the punch - and that allows the punch to select the proper Baudot code to punch… no cam shaft needed.

3 — Attached - the best diagram you may find, but mileage will vary :) .

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> On Sep 23, 2023, at 4:32 PM, Nick England <navy.radio at gmail.com> wrote:
> 
> I tried to help out a fellow with a M19 today - and I know nothing about that era equipment - first time I had touched one. So no surprise that I wasn't too helpful figuring out where a stray wire was supposed to go. 
> 
> Symptom - This punch magnet is always on in T and KT, off in K.
> 
> Question 1 - can you remove and standalone test just the keyboard/perf assembly with 120vdc (obviously having to rotate the driveshaft by hand).
> 
> Question 2 - is the punch magnet supposed to only get activated by the closure of the cam contact on the keyboard shaft? Or is it one of those oddball things that is always on except to punch via spring power? 
> 
> Question 3 - is there a good simplified WD for a dummy like me?
> 
> Thanks,
> Nick the M28 guy