[Skimmertalk] Skimmer Experiance: 160M and 10M

[Dean R. Madsen]

ARRL 160M
Skimmer was used both on a soft rock receiver 
located at my QTH and on a Flex 5000a with 
Skimmer in IF mode and WD5EAE’s Skimmer Scheduler 
located at the contest station.  Paranoid 
callsign validation was used on both instances.

Skimmer wasn't useful in periods of moderate to 
high activity.  There were so many erroneous 
spots that it was better to have both ops concentrating on the run frequency.

It appears that Skimmer was spotting calling 
stations.  This seems to happen on stations 
running with “test callsign callsign test” and 
only with certain callers.  Maybe these certain 
callers are better at matching the running 
station’s frequency and with the end of the CQ 
message being “test” (CQ to CW Skimmer?) the CQ 
and callsign twice threshold is met by the end of 
the CQ and the exchange by the running 
station?   Just speculation, as I didn't have 
time to investigate this during the contest.

Show non-workable spots was initially turned off 
to reduce the clutter on the band map, but was 
soon turned on so that the correct call would be 
shown for spots that had decoding errors with the callsign.

Skimmer showed its worth when the rates fell and 
the spotting station had time to check the few 
spots that were generated in between the running 
station’s CQs.  Skimmer did find new stations to 
work.  The remote skimmer with a shortened dipole 
at 35ft provided more spots than the local 
skimmer in IF mode (due to the running station, 
limited to 20khz and use of directional beverage antennas?).

This experience was a solid improvement over CQ 
WW when skimmer was disconnected from the logging software.


ARRL 10M
Skimmer was used in IF mode using a Flex 5000a 
that was also the contest radio.  During the 
first three quarters of the contest when signals 
were weak and gone quickly, I could see the 
signal on the Flex 5000 PanaFall display and I 
was working the station by the time CW Skimmer 
spotted the station.  I also experienced a lot of 
crashes of CW Skimmer early on and then it 
somehow stabilized (I plan to send the log to 
Alex). During the short period the 2nd day when 
the band actually opened, I found skimmer to be 
pretty helpful.  When I noticed a new skimmer 
spot and no one was answering my CQs I was able 
to click on the spot, be right on frequency, work 
the station and return to my run frequency if 
skimmer hadn't spotted another station to work 
(since my 20khz decoding window had changed).

For the 10M contest the cluster spots weren't 
useful.  Too bad the logging software doesn't 
show skimmer spots in a different color.  I don't 
want to disconnect from the cluster so that I can 
see who is working what area and know when I have 
been spotted (and then be disappointed when it 
didn't really make any difference).  Maybe it is 
time to expand from 2 monitors to 4 monitors so 
that CW Skimmer is visible along with the radio software and logging software?

I would like to see specific support for the Flex 
radios with CW Skimmer.  The main problem is that 
the IF mode is limited to 20 kHz due to filters 
of standard transceivers.  With the Flex radio 
the whole 96 or 192 kHz is available to CW 
Skimmer, the center frequency is the VFO frequency.

If two copies of CW Skimmer (one for each 
receiver – VFO A and VFO B) would run in a “Flex” 
mode with OmniRig reading the center/VFO 
frequency, I think it would be an almost ideal 
implementation:  The operating antenna and 
skimmer antennas are the same with no concern of 
accidently transmitting in to the skimmer 
receiver and you can operate and skim two bands simultaneously.

Next Contest:  Stew Perry
I plan to be active in the Stew Perry 160m 
contest next weekend as a Multi-OP-single-person 
with skimmer.  It looks like cluster is 
prohibited even for Multi-Op entries, so it will 
be interesting to see skimmer-only spots on the 
band map.  I will post again if I learn anything new.

73,
Dean - N0XR




Dean R Madsen
dean at acsnet.com          ICQ:5510840