[GreenKeys] WU tape reader 1-A

[Duncan Brown]

Nick,

The AWA Museum has a WU Mux Specification Book (c1918), which includes 
your 1-A Tape Reader, but there is no timing information included.

In about 1900, Donald Murray took Baudot's Mux system and improved it by 
adding the perforated tape and code that we know.  His original system 
operated at 45 wpm per channel. In 1912, he sold the US rights to his 
system to Western Union. Your WU model 1A tape reader is c1918 and 
improvements in speed may have been made by then.

The printers used with the 1-A Tape Reader would have been the WU Model 
3 & 5 page printers and the Model 20 & 21 tape printers. They were all 
solenoid operated (no motors) and would probably have had no problem 
doing 50-60 wpm.  (WU was very efficiency minded and was always trying 
to improve throughput. One reason they went to tape printers was that 
they did not have to spend time sending CR & LF characters.)

The fact that your system only works at a slower speed makes me think of 
a problem with the stop pulse or with sufficient voltage. You say you 
are using a M14 distributor, so I assume (if you are using the standard 
motor & gears) that is generating the Start & Stop pulses correctly. 
Have you looked at your pulse train on a scope?

Are you running a normal 120VDC loop?

How are you adjusting the speed?  Just adding more time between 
characters, but keeping the character time (163ms) the same?

Good luck,

Duncan
K2OEQ

> Hello group
>
> Does anyone know how fast the WU Multiplex Transmitter 1-A use to run?
> I finished building my own TD from scrap part of a 14TD. Full or 
> normal speed would be six characters a second (60 wpm) but the printer 
> is not happy and I get garbage out only. If I slow down the system 
> (with a time controlled cam) to three characters a second (half 
> speed), the printer is happy.
> Wondering if the mechanism of the 1-A is just not capable to keep up 
> with 60 wpm. I also don't know what kind of printer was connected to 
> the 1-A over 100 years ago and how fast that printer was running.
> Any info would be appreciated.
> Nick - N0NCQ
>
>
>
>


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