Talbot Andrew wrote:
[snip] Just as an example of a visual code, 7 frequency levels, using
two sucessive symbols per character gives potential for 49 different
symbols, enough for letters numbers and a few punctuation. There
would be no need to turn off the Tx for any symbol, as a space could be
coded as a character, thus removing ambiguities with dots and noise
spikes.
[snip]
Just out of curiosity : I was thinking, a few weeks ago, to a signalling scheme
that makes use of 2-out-of-12 tones, with the two tones being sent not
sequentially, but simultaneously. I do realize that this would mean that the
PA must be linear. Is this a though requirement for the present crop of PAs
around ? How much would this requirement be of obstacle to the adoption
of such a scheme (which could also be FEC corrected...). TNX
73 Alberto I2PHD
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