[GreenKeys] Model 31 video

[Duncan Brown]

John,

OK on the series-governed motor.  We had some discussion on the motor 
recently.  It is typical for the military to use series- governed 
motors, and I assumed that the WU units had synch motors. But Jim Haynes 
pointed out that Teletype Corp. had trouble getting a small sync motor 
with enough torque to drive the M31.  I don't remember now if any of the 
WU units ever showed up with sync motors.

A series-governed motor must switch a resistor in an out of the motor 
winding to control the speed, but that can cause RFI. So the military 
version, TT-30, which was going to be used in RTTY/RATT service used a 
tube to do the switching more cleanly.  The 35L6GT sticks up on the top 
of the unit and is quite noticeable.



Thanks for sharing your unit.  Have fun,

Duncan
K2OEQ



On 16-Mar-22 10:48, John wrote:
>
>    Greetings Greenkeyers!
>
> Here are a couple of videos I took the evening I got the Mod 31 
> working.  I had oiled everywhere I could get to (I do have all the 
> manuals thanks to Nick E.!) and turned it through by hand  - nothing 
> seemed to be binding, I connected it up in the shack loop to ITTY, 
> powered it on, and voila! it prints! Even the ribbon is still supple 
> and ink-y.
>
> A question was asked concerning the motor:  this one has a GE 
> series-governed motor, 115V at 7200 rpm (I doubt it is set to go that 
> fast). There is an "AC  DC" switch on a component bracket above the 
> motor.  And yes she's quite electrically noisy - in the video of the 
> print segment, as I got my phone close to the machine you can hear the 
> popping of the governor sparking.  If there's a 35L6 in there I can't 
> find it...
>
> This one is in a Western Union badged clamshell portable case with a 
> big leather handle - all of it is in pretty good shape - even the 
> detachable copy-holder is with it.
>
>
>     This is the front of the machine in operation:
>
> https://www.dropbox.com/s/10hmmeuny7ra206/20220314_185252.mp4?dl=0
>
>
>    This is a side view of the drive, cams, and end-of-line mechanism.
>
> https://www.dropbox.com/s/xojllrigv4wkrhd/20220314_185401.mp4?dl=0
>
>
>   Cheers
>
> John KB6SCO
>
> Carson City
>
>
>
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