[SADXA] Question for the FT-8 experts.

[Jim W]

On 7/2/2020 2:48 PM, mike at 1911parts.com wrote:
> Jerry,  I can easily hear an FT8 signal at -20.  I can also see a FT8 
> signal on my Flex radio panadaptor.   So a CW signal at the same level 
> would be easy to work.  The weakest FT8 signal I've worked and 
> confirmed was a -24.
>
> Regards and 73's,
>
> Mike Chasse
> w7wrj
>
>
>     -------- Original Message --------
>     Subject: [SADXA] Question for the FT-8 experts.
>     From: Jerry Wothe <jdwothe at cox.net <mailto:jdwothe at cox.net>>
>     Date: Thu, July 02, 2020 2:35 pm
>     To: SADXA Reflector <sadxa at mailman.qth.net
>     <mailto:sadxa at mailman.qth.net>>
>
>     At what reported signal level on FT-8 can one expect the path is
>     good enough for CW work?
>
>     W6XI
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A -20 signal might be workable on CW but with some added assumptions.  
First assume minimal QSB conditions, so that the weak signal is fairly 
stable in signal strength.  Also assume a fairly narrow filter setting, 
probably around 150 Hz or less. With a setting that tight we also need 
to assume that the transmit signal is reasonably stable in frequency.  
Too much drift and the signal is out of the passband.

Somewhere on the Internet I've seen a chart that shows the minimum 
receivable signal for the different modes, from JT-65 to AM.  I just 
can't locate it at the moment.  Perhaps someone in the club has ready 
access to that information.  That would give us all a more precise 
information source.

Jim  W9FI