Jan found out that his misleading results were due to having two programs on the same PC, now he sees the improvement on 1.60
David did a 8.5 Hour test and saw 23.7% more spots on 1.60
I have posted a note of my test results on the LF group so the story is out now! The improvement is staggering! And I do like the way that the facilities have been put together. The Hopping Scheduler is a very nice way of making clean band changes without the "Wrong Band" risk as well as being a great tool in it's own way. You also don't need to run a spec anl as well to see what is happening.
This was the very detailed analysis Alan G8LCO posted on the RSGB LF group:
WSPR
is now included in the WSJT package as an alternate mode alongside JT65 and JT9. I loaded the free software just before Christmas running
into some issues because I had not changed the audio settings. After
changing to the settings in the instructons everything worked.
The
WSPR mode use is a little different, band hopping is available so
instead of manually having to change bands waiting for decoding to end
etc etc you can now preset the next band(s) making the band change quick
and certain. If every user picked up on this feature the "Wrong Band"
issue which messes up the logs could be a past issue! that would be a
very significant "WIN" for the WSPR database users!
The
decoding now uses a two pass process, strong signals are processed then
removed allowing weaker signals to be decoded. This makes a very
substantial difference!
On
Dec 27 I ran a comparison, I used my normal antenna and Rx to produce
audio which then went to two seperate Rx's, a laptop running WSPR 2.12
which was a known good performer and another PC running WSJT-X 1.60. I
chose to listen to 160m as it was busier than 620m at that time. There
is also the prospect of TA spots. The test was run overnight.
It was quickly evident that the two pass decoder was producing more spots than the stand alone WSPR 2.12
In
some time slots 1.60 produced 6 decodes to 2.12's 3 decodes ! The
main reason was that when two signals were close the old decoder only
found the stronger signal wheras the two pass decoder seemed to decode
all of the signals visible on the spectral display. I had decodes of
signals 2 Hz apart with 20dB amplitude differences whereas 2.12 lost
weaker signals 5Hz apart. Some -10dB signals decoded 1 in 6 times on
2.12 but every time on 1.60. SNR's were broadly the same however a few
signals decoded 1,2 or 3 dB higher on 1.60.
One
feature of WSPR 2.12 is that high level signals seem to top out around
+13dB so very strong signals peg at +13dB or so. The 1.60 software has
produced SNR numbers up to +20dB so we can better see crocs blasting
away. Hitherto I have run Spectrum Lab alongside WSPR so I am well aware
of the levels of some stations!
For
those used to 2.12 WSPR the new version takes a bit of getting used to
as there are significant differences and many new facilities that
extend the way we can use the software.
The
spectral display has seperate gain and bright controls with the
waterfall having it's own controls. There are several pallets and
display widths to select and an early decode option that displays the
decode earlier than 2.12 does. There is also a 2 min "thermometer" style
display at the lower edge indicating the time in the slot cycle and a
box giving the progression of the four time periods in the Hopping
Shedule, night, dawn grey line, day and sunset grey line. That I found
very useful.
For
me the package seems to work outstandingly well, decoding is better
than ever and quicker, the spectral display and waterfall are flexible
without over complication and the very clumsy old style band changing is
now very quick, risk free and certain. The development people and the
testers have done a very good job.
However
decoding weak signals is not simple, different people have different
equipment, noise levels and operating practices. I would advise against
running different decode software at the same time on one machine, there
is a possibility of misleading results. I would like to thank Jan,
David and Roger for helping clarify matters and their independent
testing.
Alan
G8LCO
1 comment:
The thing I like about the new band-hopping is that, all things being equal, everyone will be on the same band on the same minute of every hour. If I spot K9AN at 12 past the hour on 17m, we both hop to 15m next and I can try my chances with them there. If I don't enable 15m then the program randomizes one of my selected bands for that slot instead. Stations who only TX on 10m should expect to see greater chances on these 10m slots, which are 18,38 and 58 past the hour. One other bonus, I selected MF as RX only and actually have spotted 3 different WSPR stations here in the states. Usually that band is extremely noisy for me though.
73 KC1AWS Gary
Post a Comment