[Skimmertalk] Skimmers @ NZ1U/KB1H & W1UJ

[W1UJ at arrl.net]

The infrastructure @ NZ1U was feeds from the K3 Softrock Panadapter, a 
Softrock skimmer fixed on 40m, KB1H node, W1UJ K3 SR Panadapter, on 
whatever band I was active on and there was a fixed 40m Skimmer here also.

My experience was that the K3 would spot the stuff around the active 
frequency.  AT KB1H, the K3 was a dedicated spotting station which did 
not transmit. Transmitting or changing frequencies would stop spotting 
and the validation process would begin again.  On an active radio, it 
didn't help much
 I would leave the rig, without transmitting or frequency changes for 
about 5 minutes and 'sweep' the stations that I didn't work that were 
spotted and not busted calls.
Where the KB1H spots were low angle/dx spots and the W1UJ spots were 
more NVIS local stuff.

Filtering-
Since there were huge amounts of busted calls and huge amounts of spots, 
the skimmer's filter which defaults to setting 'Normal' to Aggressive 
and later to Paranoid. (Skimmer's 4 validation settings are Minimal, 
Normal, Aggressive, Paranoid. )
There is also a setting where the spots will only send validated calls 
sending CQ this again worked well.
The absolute best setup for the filter for the CQWW was setting the 
spots only from DX stations, calling CQ, with the 'Normal' validation 
setting. Skimmer validates it's skimmed calls by comparing it against 
the K5ZD Super Check Partial MASTER.dat files.   To filter out the local 
stations, the available MASTERDX.dat only includes non-US call signs so 
the DX mostly came through.  There were still locals spotted, but much less.

Operating-
Changing frequencies, or transmitting would delay spots as the 
validation processes took place.  I must say, that working the stations 
spotted through Skimmer has renewed another anchor to keep me hooked 
with cool new technologies.  It was much, much more fun on  single band 
ARRL 160m or ARRL 10m contests.  My station is a real poor radio 
location, so not expecting much, I left the Skimmers plugging away.
I attribute a good number of multipliers from W1UJ were worked from 
Skimmer spots where the KB1H/NZ1U was more for QSO's since we try 
running more than S&P, the mults call us.

With the high power during  contest, the Softrock Skimmers would spot 
different variations of the station call signs when were were running, 
the K3's filtering would allow same band monitoring I bet.
NZ1U would spot NG1I, NG1U etc... etc.. throughout the band on all 
freq's at the same time.

I have just this week modified my K3's IF output buffer circuit to have 
more signals 'visible'.  I have not yet measured performance differences 
from stock, but a quick scan of the bands did seem like there were more 
signals. We will soon modify the KB1DFB K3 @ KB1H/NZ1U to enhance our 
'skimming' if the mod seems beneficial.

We are using K1TTT's winTelnetX software which is perfect for all of the 
setups and testing between multiple stations.
Thanks Dave.

Future related projects @ KB1H/NZ1U include;
-Modify KB1DFB K3 IF
-Place a multi-band Softrock (once the bandpass filters are worked out) 
on a DX Engineering ground mounted vertical receive antenna, possibly 
with the scheduled band changes software.
-Establish a sort of isolated DX Spider node so Skimmer spots can be 
shared and more could contribute.  Like the dxwatch.skimmer website, but 
an actual packet feed&filters.
-Assist Pete with testing stuff.

Jay- W1UJ