[GreenKeys] 7.00 vs 7.42 unit code

[Nick England]

Doing some machine shuffling this week made me think about this - please
steer me back on course if my thinking is off.....
Truth-
7.42 unit code has a start bit and 5 data bits of equal length (1.00 unit
each) and a stop bit 1.42 units long.
7.00 unit code has a 1.00 unit stop bit.
45.45 baud code can be either - each 1.00 unit data bit is 22ms.
So 7.42 unit at 45.45 baud is 60 wpm
and 7.00 unit code at 45.45 baud is 65 wpm
There's a chart at http://www.navy-radio.com/tty/speed-feed.gif

Consequences-
These two do require different gear sets - you can't just put 60wpm gears
(368 opm) into a 7.00 unit machine (390 opm) - that would make the baud
rate wrong and your selector and keyboard transmitter timing would be off.
A 7.00 printer can copy a 7.42 keyboard or 7.42 TD no problem.
A 7.42 printer can copy a 7.00 keyboard if you don't type at max rate
A 7.42 printer probably cannot copy a 7.00 TD

What about sending RTTY with a 7.00 keyboard or TD? - will the computer
software RTTY folks copy it OK? I assume so, but don't know for sure.

Comments welcome.....

best regards,
Nick England K4NYW
www.navy-radio.com
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