[hpsdr] Modified PowerSDR with selectable FFT size and selectable palettes...contest report

[w3sz]

Hi All,

Just a report to all regarding the performance of the modified 
HPSDR-PowerSDR code with larger FFT sizes during the ARRL VHF QSO Party 
[VHF/UHF/Microwave contest] this past weekend.  I consider the microwave 
contests to be the acid test for any SDR/waterfall combination, and it 
was performance in these microwave contests that convinced me that 
PowerSDR needed to be modified to perform up to my expectations.

I am pleased to be able to report that with the new larger FFT sizes [I 
used an FFT size of 262144] I was able to see with PowerSDR every weak 
signal I saw on Linrad, with no difficulty.  Both programs 'saw' signals 
that were below the threshold for copying [CW].

In NO case during the contest did a station hear me that I could not 
copy with PowerSDR.  There were as usual several stations that I could 
find with the waterfall, and then copy completely Q5 with no dropouts, 
that could not hear me at all.  That is likely as much an optimized 
tower-mounted preamp/transmit power issue as it is anything else, but 
the bottom line is that with the modified PowerSDR you will NOT likely 
miss seeing [and hearing] any station on the microwaves that you might 
see/hear with any other rig, and you will likely pick up quite a few 
that you would not see/hear with a non-PowerSDR-equipped rig [other than 
Linrad or something equivalent].

Whereas I had previously needed Linrad to find the weak microwave 
stations in every microwave contest, Linrad was, due to the improved 
performance of the modified PowerSDR, totally superfluous this contest, 
and I only kept Linrad running so I could prove to myself that in fact I 
saw with PowerSDR everything Linrad could see throughout the entire contest.

The PowerSDR code ran for the entire contest on 5 HPSDR setups, with no 
glitches or crashes during the entire contest period [except I shut down 
Saturday night through early Sunday morning due to thunderstorms in the 
area].  Since fixing a cut-and-paste-engendered bug around May 25, I 
have seen no exceptions, crashes, or other unusual behavior with the 
modified code.

After changing FFT size you need to exit PowerSDR and restart the
program to have the new FFT size available.

The files remain online, located as follows:

A zip file of the PowerSDR.exe file and the rest of the /bin/Release
directory are at:  www.nitehawk.com/w3sz/Release.zip

A zip file of the entire Modified PennyMerge directory [about 100 MB]is
at: http://www.nitehawk.com/w3sz/HPSDR_W3SZBUF.zip

A grep of 'w3sz', which should capture most of the changes is at:
http://www.nitehawk.com/w3sz/w3szpowerSDRgrep.HTM

A grep of 'GlobalClass' should pick up most stragglers, and is at:
http://www.nitehawk.com/w3sz/GlobalClasspowerSDRgrep.HTM

A text file with a few more details is at:
http://www.nitehawk.com/w3sz/simplePowerSDRMods.txt

These are pretty much the newest files, except for perhaps a slight 
'tweak' of the default waterfall levels to suit my personal preferences. 
  At this point the modified software behaves exactly as I want it to, 
and I have no plans to modify it further.

-- 
73,

W3SZ
Roger Rehr
http://www.nitehawk.com/w3sz