NR2DX asked: "If read your post correctly you are saying that you are
working against an ambient noise level of 20-30 db over S9 is that
correct.? "
No. The S9+20 to 30 dB is the S meter reading when all the FT8 stations
are transmitting after the band opens a little. Receiver bandwidth was
1.5 kHz. Tuning to a clear frequency my noise level was about S1 with
200 Hz bandwidth when I made these tests. I usually used 100 Hz
bandwidth when measuring the signal level of the FT8 signal for
determining his actual strength. Sometimes less if there were multiple
signals in the passband.
W0MU asked: "Have you attempted to open a conversation with the
creators of the mode and discuss what you are seeing?"
No I have not. I have also not seen any published data from anyone
showing actual performance. All I see are claims based on calculations.
Theory is good but it has to agree reasonably well with actual
measurements. If not, one of the two is in error.
Yes DX last year on 160 CW was pretty scarce. Even when I was hearing
S6 FT8 signals from Europe I would tune down to the CW portion of the
band and usually there were no CW signals there.
When I was doing these tests I was using WSJT-X in FT8 mode on 160
meters. I was using version 2.0.0, which was the latest version at the
time.
Jerry, K4SAV
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|