Topband: FT8 Observations

[Tim Shoppa]

On being able to hear signals at -12 to -17 dB on FT8, I do broadly agree. A CW signal at those levels would be easily heard and copied by any decent CW operator.

I think a lot of the FT8 “processing gain” claims, assumes a really poor CW operator. A 0dB FT8 signal is not at noise level, it is way way above noise level.

That said, this morning at my sunrise (noon in Europe) I was printing Italian stations on 40M FT8 and I was being decoded in Europe too, often at the -22 to -24 dB level. (I was barefoot and I’m assuming the italiAns too). Those are levels below what I can hear or copy on CW. I can work Europe midday on 40CW in winter but not so easy in spring or summer.

Tim N3QE

> On Apr 22, 2018, at 10:17 AM, David Olean <k1whs at metrocast.net> wrote:
> 
> I have been playing around with FT8 on 160M and am a bit puzzled. I have made plenty of contacts, but with many stations, it seems to require an inordinate amount of power to get their attention, or they do not respond at all. I also have noted that I can hear in a 2.8 kHz passband, signals that register from -12 to -17 dB. About the weakest that I see is a bit more than -20 dB. Does this mean that FT8 is only a few dB better than CW?  I have my time set accurately and I try to place my TX signal away from whomever I am calling on a clear spot on my waterfall.
> 
> Some stations are easy to work, and I have worked across the country (FN43 to a CM grid) running just 1 watt. It just seems that there are many stations that are not hearing much, but are making plenty of noise.  Am I wrong?
> 
> I am working on cleaning up my 160 setup and have 8 beverages running and they are all pretty quiet now that I installed plenty of ferrite chokes around on the RG-6 feed lines.  I am looking forward to next fall and winter.
> 
> 73
> 
> Dave K1WHS
> 
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