Elimination of CW is a loss in the number of ways we cancommun...
 

Cecil, W5DXP wrote:
"What Baud rate would be required for a human to copy RTTY by ear?"

The Baud rate is about twice the bandwidth according to Bell Labs`
Nyquist. Then Shannon, also of Bell Labs came along saying information
could be transferred much faster if the signal to noise were 30 dB or
better.

Using the standard Baudot or Teletypewriter code, about 8.000 words per
minute can be transmitted.

Operators who can copy Teletype by ear are likely to be rare indeed.

Best regards, Richard Harrison, KB5WZI

Elimination of CW is a loss in the number of ways we cancommun...
 

"Richard Harrison" wrote in message
...
Cecil, W5DXP wrote:
"What Baud rate would be required for a human to copy RTTY by ear?"

The Baud rate is about twice the bandwidth according to Bell Labs`
Nyquist. Then Shannon, also of Bell Labs came along saying information
could be transferred much faster if the signal to noise were 30 dB or
better.

Using the standard Baudot or Teletypewriter code, about 8.000 words per
minute can be transmitted.

In the heyday of RTTY as I remember it, you could put two 8-channel muxes
(85 Hz AFSK per channel) into one SSB transmitter. One of the muxes was
at baseband and the other was heterodyned up by about 1800 KHz and
"stacked" on top. Nyquist might predict 8,000 wpm capability but I never
saw hardware that approached that number. With QPSK, I dunno ...


Operators who can copy Teletype by ear are likely to be rare indeed.


I can recognize a test tape of RY's and I can hear the periodic CR CR
LF
but I can't recognize any of the alphabet, even at 60 WPM (45 baud)

Elimination of CW is a loss in the number of ways wecancommun...
 

Sal M. Onella wrote:
"I can recognize a test tape of CR CR LF but I can`t recognize any
of the alphabet, even at 60 WPM (45 Baud)"

Back when AT&T was the American Telephone and Telegraph Company, they
leased 30-Baud battery powered circuits suitable for manual telegraphy
or low-speed data. Biggest customers were the military and FAA.

Best regards, Richard Harrison, KB5WZI