[GreenKeys] Early Teletype in the RN

[Jim Haynes]

I know high speed (500 wpm) Morse was used into the WW-II period in the 
U.S. and perhaps later.  When I was a youngster we had a broadcast radio
with shortwave bands.  We would tune across these powerful droning signals
and I was told they were high speed Morse.

Robert Sprague of Press Wireless wrote an article in the November 1944
issue of Electronics magazine which is probably well known to most RTTY
enthusiasts.  Titled "Frequency Shift Radiotelegraph and Teletype
System."  He starts off saying

"Commercial radio communication by Morse Code has been standard since
the advent of radio.  The dot-dash system has never bgeen entirely
superseded by voice.  Though code has its drawbacks and is subject
to error in transmission and requires highly schooled personnel, it is
still the basic means of handling high-speed commercial and press 
traffic."  [Tells about the Byrd South Pole expedition of 1939-1940,
PREWI supplied FSK equipment including a 500 watt transmitter and
transmitted pictures by FM FAX over 8000 miles that were received
with the clarity of standard wirephoto pictures.]

"As much as 20 db signal-to-noise increase can be expected using
frequency shift transmission.  A small, mobile 400-watt frequency-
shift transmitter on the beachhead in France is transmitting press
traffic to this country at a rate of 500 words a minute, over a
million words a month, where in former days a 50-kilowatt transmitter
had trouble in maintaining the circuit."

So for Morse at 500 wpm with on-off keying you need a powerful 
transmitter, but the receiving equipment is pretty simple, and then you
have a roomful of operators reading the ink recorder "slip" and
transcribing it on typewriters.  That's almost ten times as fast as
a single Teletype, and if the Teletype machine cost $1000. and the Morse
operators were getting, what? maybe $1000 a year?, you can see why
Morse was popular, and why FSK was a big win as well.

But when operators get expensive, and you get means to multiplex several
Teletype signals on one transmitter, then the Teletype starts to look
a lot better.

This is an apocryphal story, but someone told me of being in a signal
center at Ft. Sam Houston at the outbreak of WW-II.  And the receiving
room was literally knee deep in Morse tape slip waiting to be transcribed
by operators.