|
Here are some more example plots from last
night, June 2 / 3. To be honest, I can't find much confirmation for my
earlier statement of WSPR-15 generally showing higher SNR (with the one
exception of PA3ABK). I guess the remaining systematic
differences may rather have to be attributed to different local QRM levels
on the two frequencies.
Best 73,
Markus
Sent: Tuesday, June 02, 2015 10:35 PM
Subject: Re: LF: Dual Mode WSPR Beacon running
again
Hi Andy, LF,
attached are examples of SNR plots for WSPR-15
(blue, G8IMR) versus WSPR-2 (red, G4JNT), as extracted from the spot database.
Times are hours after midnight last night (ie -2 means 22 UT), amd data points
are plotted at the middle of the respective transmission interval.
G3WCB at 181 km consistently showed similar SNR
values for both modes, with relatively little scatter. At intermediate ranges
around 900 km, DF6NM and LA3EQ experienced a lot more variation, probably caused
by deeper fading. Again there's a trend that reports for -15 seem to be a bit
higher than for -2, with a few significant exceptions. Finally the most distant
station SM2DJK seemed to see less variation and more similar SNR values. In the
morning hours, -15 was still decoded there while -2 was not.
Here I was again running two instances from a
single WSPR-X installation, which generally worked well, except for a couple of
failed database uploads at full and half hours - apparently when both instances
try to upload simultaneously only one gets through.
Thanks Andy for setting up this interesting
experiment!
Best 73,
Markus
(DF6NM)
Sent: Tuesday, June 02, 2015 10:17 PM
Subject: LF: Dual Mode WSPR Beacon running again
Callsigns G4JNT on WSPR2 and G8IMR on WSPR15,
(very) approx 25% duty cycle on each (when long term averaged)
33dBm EIRP
Tnx to G3WCB last night who copied every one on my transmissions, I was
able to check out the transmission sequence and check the modelling of the
sequence generation. So with the aid of a bit of Basic software I can now
predict what the transmission sequence will be for any particular turn on
time.
Andy G4JNT |
