[GreenKeys] Teletype M12 KSR owners

[Doug Alderdice]

My M12, sadly, is not running.  The individual components are 
functional, i.e. I can power up the motors on the keyboard and the 
printer and they run and they are mechanically complete, but the machine 
as a whole does not run.  I acquired my machine in the early 90s from an 
older local ham when he was downsizing and he had completely rewired the 
machine to work with a tube keyer to minimize the RFI when using it on 
the air.  The keyer was not operating, there were no schematics, etc. 
He had completely rewired the table to work with the keyer ... and had 
done things like wire the power leads to the printer and keyboard motors 
with 20 AWG wire!!

I removed all of his wiring and have tried to get it back to original, 
yet all I get on the machine are random characters.  The keyboard works 
as I can drop it into the local loop here and can type on it just fine 
to the other machines in the collection.

I am fighting a number of variables: the condition of the contacts on 
the table and the keyboard and printer, the contact block on the table 
is cracked and needs to be glued or epoxied back together, and the 
keyboard itself has been completely rewired at one time and the last 
time I spent some time with the project I had come to the conclusion 
that contact wiring on the keyboard doesn't match a schematic that I 
have for the M12 keyboard.

When I first got the machine I set it up on the kitchen table one 
evening and hooked it up with every clip lead I own and managed to be 
able to type on the keyboard and have it print on the printer.  I recall 
that I couldn't type at full speed on the keyboard and have the printer 
follow accurately and all of the machinery made a tremendous racket, as 
well as the electrical part of it creating a ton of RFI.  So I know it 
*should* work, but that table wiring is proving to be elusive for 
something that should be relatively simple.  And of course there is 
never enough time for all of the projects.

I do have the cover for the machine.  I will try to get some photos and 
measurements of it.  I believe Don needs that information as well and I 
think I promised him that a long time ago :redface:

I haven't been to the AWA museum yet.  It's been a "gee, we should do 
that sometime" item for a local ham radio buddy and me for some time 
now, but we haven't managed to do it.

Oh, and yes, you do need a separate DC supply to run the selector 
magnets in the printer.

73,

Doug, KA2WFT


On 1/23/2015 8:51 PM, Duncan Brown wrote:
> Doug Alderdice
> Steve Ripper
> Gerry Block
>
> Is your M12 working??
>
> I'm looking a the M12 schematic, fig 2.2a1, in Kretzman's RTTY Handbook.
> Am I correct that you need a separate 110VDC, _260 ma_ supply just for
> the selector magnets (separate from the loop supply)?
>
> The unit we have has a new terminal strip with new wiring and about the
> right number of terminals, so I am assuming (hoping!) it is wired
> similar to fig 2.2a1. (unit is at the Museum, so I won't get to play
> with it again until Tuesday.)
>
> What holds the paper roll? Is it mounted on the cover? (I don't have the
> cover.)  There was a sheet-metal u-bracket mounted to the inside of the
> table.  It was falling off, so I removed it.  But now I am thinking
> maybe its purpose was to hold the paper roll!  (I think that I can
> "borrow" a bracket from a M26.)
>
> Doug - we are practically neighbors!  Have you ever been to the AWA
> Museum??  We have lots of TTYs (besides wireless equipment).  Come over
> some time & I give you a personal tour!
>
> Thanks & have fun,
>
> Duncan Brown, K2OEQ
> USASA  31J30
>
> Antique Wireless Association Museum Asst. Curator, Commercial Equipment
> (also Chief TTY operator & repairman)
> http://www.antiquewireless.org/