I am experimenting with a new 2Tone capability that processes repeated
strings. Example sending callsign or name or QTH or any 6 or longer RTTY
character string twice with space characters between the strings. 2Tone
looks for repeated strings and combines the two sets of analogue data,
decodes it and outputs it.
Example I send "G3YYD G3YYD " (quotes are for email clarity) but say this is
decoded as "G9YYD G3YYG " then the decoded output is "G9YYD G3YYG { G3YYD }
". 2Tone has taken the two character strings and combined them to display {
G3YYD }. The brackets telling the operator that this has been made from the
repeat.
On average by combining the two sets of analogue data this will improve the
signal to noise ratio by 3dB. In Character Error Rate (CER) terms this will
take an average 10% CER to about 1% CER. A significant improvement. But like
all statistically based systems there is always the probability of false
repeat detection and also that the { } output may be incorrect. The
internal settings within 2Tone are a compromise between false positives and
missing possible repeats. Too sensitive and it matches too often when it
should not and less sensitive it will miss more possible repeats.
This function can be switched off/on by unchecking/checking Setup Menu,
Repeat Match.
I need some testers to use the function and then email what you think of it
and how well it worked/didn't work. Should it be made more sensitive (more
false positives) or less sensitive (more missed opportunities). Also should
2Tone suppress the {} when both sent strings have the same decode. Can you
think of a better name to describe it than Repeat Match?
To be a tester please email me direct asking for a copy. You need to make
sure your ISP will take 2Tone.exe in a zip file (about 158Kbytes). Some
ISPs, e.g. gmail, strip/block emails with such an attachment.
73 David G3YYD
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