[GreenKeys] Model 14 TD - weirdly coded transmission head

[tony.podrasky]

Hi Duncan;

It had a single head.

Here's a picture one of the guys sent me:

http://www.navy-radio.com/crypto/tt21-distrib-01.jpg

UE,
K2EAA - TONY
NNNN
ZCZC

On 05/13/2020 05:41 PM, Duncan Brown wrote:
> Tony,
>
> Did that TD have two tape heads? Could it read two tapes simultaneously?
> (pic enclosed)
> There was a time-division multiplex version of the M14, TT-26/FG used
> during WWII, that had two tape readers and about 14 sectors on the
> distributor. Each bit/sector was about half the normal length (ie ~11
> ms).  See TM 11-2222.
>
> The two tape messages would be sent out on the same line. At the
> receiving end, two printers on the same line would have their Range
> Finders set to opposite ends of the range. One printer would copy the
> "early" bits and the other printer the "late"  bits.
>
> If your mystery TD only had one tape reader, I don't know what it was.
> Sounds like your solution of connecting all the sectors together and
> then cutting them to the proper size should have worked.  The
> printer/reperf selector mechanism only uses the middle 4-5 ms of each
> pulse, so it should not have been that critical.
>
> Have fun,
>
> Duncan
> K2OEQ
>
>
> On 12-May-20 18:04, tony.podrasky wrote:
>> GA Oms;
>>
>> When I got started in RTTY, after the model 15, I
>> picked up a model 14 TD.
>>
>> I couldn't get it to work.
>>
>> When I showed it to someone they said that the
>> transmission head was wrong.
>>
>> Instead of 6 22.ms bits (1 start / 5 data / 1 stop bit)
>> it had something more like 6 11.ms bits (1 start / 5 data /1 stop bit)
>> and the stop bit was huge.
>>
>> I tried soldering the entire ring together and then cutting it
>> to fit the standard bit times, but when you're talking about
>> MILLISECONDS, it's pretty tough to cut something that accurately.
>>
>> Has anyone seen something like that - and what was it used for?
>>
>> UE,
>> K2EAA - TONY
>> NNNN
>> ZCZC
>>
>
>
>
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