[GreenKeys] M19 perforator punch question

[Nick England]

Thanks, Eric - and thanks to all who have responded with helpful info and
links to manuals.
One of the reasons for the session yesterday was for me to deliver a 120vdc
1a supply to provide enough oomph for the punch.

I understand a more about the punch activation now - Note 13 on the P90.954
WD that you sent is a good explanation - The M19 K/KT/T works essentially
like the 28ASR with which I am familiar, the main difference being that the
M19 punch is powered by electromagnet and the M28 punch is powered by the
motor shaft.
K mode - no punching
KT mode - Cam Pulsing Contacts on the keyboard drive shaft pulse the punch
magnet
T mode - the U-Bar Contacts pulse the punch magnet (meaning punching is not
restricted to machine speed as Eric V. pointed out)

Cheers,
Nick England K4NYW
www.navy-radio.com


On Sat, Sep 23, 2023 at 10:19 PM E. <hanyou at xsmail.com> wrote:

>
> 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 :) .
>
>
>
> > 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
> ______________________________________________________________
>
>
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