[GreenKeys] Model 31

[Duncan Brown]

Eugene,

The M31 was probably the smallest teletypewriter ever made. (being a 
tape printer rather than a page printer helps!)

It was originally designed for the military (TT-30/AGA) with a 24VDC 
motor/dynamotor for mobile & aircraft use..  The dynamotor produced 
250VDC for the loop & TU.  The motor speed control used a 35L6GT for 
switching a resistor in series with the motor winding to minimize RFI.  
There was an extra set of contacts on the TTY transmitter cams to key 
the radio transmitter, so it was "Type-to-Talk".

Teletype Corp didn't sell many to the military, so they put a sync motor 
in it and a carrying case and sold the M31 to Western Union, who leased 
them out to sports casters to do remote game reporting. Only about 500 
units were built & sold.

-...-

John,

Can you confirm your M31 has a synchronous motor?

have fun,

Duncan
K2OEQ





On 15-Mar-22 15:00, W2HX wrote:
> I don’t think I've ever seen a 31. It is quite compact, or at least it looks that way. Reminds me of the model 14 strip printer (or whatever the right terminology is). Great find.
> 10 mites?! Wow.
>
> 73 Eugene W2HX
> Subscribe to my Youtube Channel: https://www.youtube.com/c/w2hx-channel/videos
>
>
>
> -----Original Message-----
> From: greenkeys-bounces at mailman.qth.net <greenkeys-bounces at mailman.qth.net> On Behalf Of John
> Sent: Monday, March 14, 2022 10:58 PM
> To: Greenkeys <greenkeys at mailman.qth.net>
> Subject: [GreenKeys] Model 31
>
>
>     Greetings Greenkeyers!
>
> A Model 31, in the Western Union 'clamshell' case, (and incidentally the copy-holder), has shown up in my shack.
>
> (Along with 10 [count 'em! t-e-n!] MITES, a bunch of Kleinschmidts, a Model 32, etc etc - more on this later...).
>
> I took it out of the case, gave it some light oil in as many places as I could find, then - after turning it over by hand for a while - plugged it in to my loop and switched 'er on.
>
> Then I dialed in ITTY, and behold! It prints nicely! Woo Hoo!! In fact it's almost flawless, save that I think the capstan has a couple of slick spots, because it over-prints occasionally at random times.
>
>
>      Attached are a couple of shots of it putting ITTY down on the paper tape - I also took some video to upload to my Vimeo site later.
>
>
> And now to plow thru all those MITE units.....
>
>
> Cheers
>
> John KB6SCO
>
> Carson City
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