[GreenKeys] Teletype Corp. machine with a tube (was acrylic case)

[Duncan Brown]

OOPS,
Bul. 1140 is the M31 Parts manual. The general M31 manual is Bul. 200, 
Sep 1947.

On 2/2/2019 17:50, Duncan Brown wrote:
> Robert,
>
> The TT-30/Model 31 the motor & DC generator is a single unit. I didn't 
> open it up to see how it is wired, but the manual (Teletype Corp. Bul 
> 1140, Oct 1947) refers to it as a "dynamotor."
>
> have fun,
>
> Duncan
> K2OEQ
>
> On 2/2/2019 12:48, Robert Downs wrote:
>>
>> Duncan.
>>
>> No argument that it is the only machine to have a generator built in 
>> but technically, it would be a Motor-Generator instead of a 
>> Dynamotor.  In a dynamotor, the motor and the generator are both on 
>> the same armature.  In an M-G set, they are separate units 
>> mechanically coupled.
>>
>> Robert Downs
>>
>> *From:*greenkeys-bounces at mailman.qth.net 
>> [mailto:greenkeys-bounces at mailman.qth.net] *On Behalf Of *Duncan Brown
>> *Sent:* Saturday, February 2, 2019 09:49
>> *To:* Nick; Green Keys
>> *Subject:* [GreenKeys] Teletype Corp. machine with a tube (was 
>> acrylic case)
>>
>> Nick,
>>
>> Teletype Corp did make a machine with an electron tube in it: the 
>> Model 31 (AKA TT-30/AGA-1) that ran on 28VDC. A 35L6GT was used to 
>> switch a resistor into the motor circuit of the series governed DC 
>> motor for speed control. It was a KTP machine that was designed for 
>> use with RTTY/RATT. They were apparently afraid the normal open 
>> contacts in the speed control would produce too much RFI.  Although 
>> running on 28VDC, the 35L6GT apparently had enough gain with 28 VDC 
>> on the filaments and would probably last a bit longer.
>>
>> The first time I powered up the Museum's unit, it seemed to run OK 
>> for a few seconds, but then it slowed down. I quickly killed the 
>> power and checked  the unit for something binding or a bad bearing. 
>> Everything seemed OK, so I powered it up and it did the same thing: 
>> slowed down after a few seconds. Then it ran fine and I suddenly 
>> realized that you had to wait for the tube to warm-up before the 
>> speed control took effect!
>>
>> There is also a 250VDC generator connected to the TTY's motor to 
>> provide voltage for the loop and the FSK converter. So the TT-30, 
>> besides being the only TTY with a tube, is also the only  TTY with a 
>> dynamotor!
>>
>> Have fun,
>>
>> Duncan
>> K2OEQ
>>
>> On 2/1/2019 20:29, Nick wrote:
>>
>>     And the vacuum tube you can see on the lower right side above the
>>     switch inside the case is just a little steampunk add-on. The tub
>>     actually works, it is a Dekatron counting tub, spinning around to
>>     an adjustable speed. At our event last weekend, I pulled
>>     somebody's leg and said: "this is a super rare tube driven
>>     teletype machine, probably the only one on the planet" - but the
>>     guy figured it out pretty quickly and we both laughed.
>>
>>     Enjoy the pics - any improvement ideas are always welcome.
>>
>>     73
>>
>>     Nick  -  N0NCQ
>>
>

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