(I've noticed lots of redux going around lately. :)
I am puzzled by what people are looking for in weak signal CW work. It
seems to me the best you can expect from a conventional receiver (even
Orion) is to keep out of the way. I.e., good sensitivity and dynamic
range, AGC that doesn't kill the signal inadvertently, good passband
filtering, etc.
If you really want to dig signals out from below the noise, you need a
"tuned detector" - the sort of thing used in coherent/synchronous CW.
In other words, your software has to make a hypothesis that there is a
signal of such and such frequency transmitting under the noise at a
particular symbol rate, and if you're really good, with a particular
"clock" phase. Then, you can decide symbol by symbol what is most
likely being sent. You can even use your prior knowledge of QSO
vocabulary (redundancy) to help fill in missed symbols.
This is what happens in our head when we copy CW. Probably a computer
can do it better, but this kind of processing is far beyond what
Orion's DSP is all about.
73, Martin AA6E
--- Barry N1EU <n1eu@netscape.net> wrote:
> n1eu@netscape.net (Barry N1EU) wrote:
>
> >I still think the Orion could do a better job with the basics of
> weak signal reception.
>
> Apologies, but I really should have qualified this statement. I've
> posted before about my own comparisons that showed the Orion gives up
> nothing to the FT-1000D in this regard. The Orion is as good as the
> competition, I just wish it were as superior in this respect as it is
> in close-in selectivity/IM immunity. I've yet to see dsp of any
> flavor by any manufacturer as a consistent advantage in reading weak
> cw signals in noise, but I'm hopeful that it's just a matter of time
> till we have more powerful processing and smarter firmware
> algorithms.
>
> 73,
> Barry N1EU
>
>
>
>
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