[RTTY] High speed RTTY

[Kok Chen]

On Jan 27, 2010, at 3:05 PM, Roger Cooke wrote:

> The BER rate increases with speed and
> using the present filters that most transceivers seem to have, namely 250Hz
> or 200Hz, I think that 75 Bauds would be a better target. I have tried 
> 75 Bauds on 80 and 20 metres with good copy and trying to keep up with the typing at
> that speed is quite stimulating!

Charles KK5OQ reminded me that the HSS contests were indeed done run at 75 baud (100 wpm).  I have HSS logs from 1997, 1998, 1999 and 2000, after which I think it was no longer run?

Nowadays, one way to experience the exhilaration of high baud rate contesting is to join one of the PSK125 contests. 

The PSK31 Varicode averages about 6.5 bits per character (less if you use only lower case characters).  Each word is usually considered to be 5 characters (e.g., PARIS in Morse) plus a space character, so that is 39 bits per word.  PSK125 runs 4 times faster than PSK31, thus it has a symbol period of 8 milliseconds.  Or 312 ms per word (3.2 words per second).  Thats about twice the speed of 75 baud RTTY :-)  (BPSK63 has about the speed of 75 baud RTTY.)

Zoom!

73
Chen, W7AY