Sunday, November 13, 2011

Opening Up SkimSrv to Get Everything in CQWW

With CQWW CW only 10 days away, and the RBN's new bigger server up and operational, we're just about ready to go.

However, as we all know, during big contests people will be running well outside the normal bounds of customary CW bands. Recently, we discovered that if you run Skimmer Server (SkimSrv) with the standard .ini file, even at 192 KHz bandwidth, you may miss some of the action. 

If you want to avoid such limitations (and you are running SkimSrv on a fast-enough computer), there is a way to make Skimmer copy CW out to the full bandwidth the QS1R receiver can handle. Be forewarned, though - we have no way of knowing how particular computer/SkimSrv/Aggregator/LAN/Internet configurations will handle the additional load. CQWW CW will, as usual, be the ultimate test, so we do not recommend implementing this unless you are going to be monitoring your SkimSrv computer during the contest.

First, you will need to be running Aggregator 1.4 and SkimSrv 1.3 - the latest releases.

the problem - the "stock" SkimSrv.ini file has the following line in it:

CwSegments=1800000-1890000,3500000-3600000,7000000-7070000,10100000-10130000,14000000-14120000,18068000-18095000,21000000-21100000,24890000-24920000,28000000-281500000,50000000-50110000

As you might guess, this instructs SkimSrv only to attempt to decode CW in the listed bands. Normally, this is a very good idea, to cut down on the number of decoders that might otherwise be spawned attempting to decode RTTY, PSK, etc. However, during a big contest, you'll miss a lot.

The fix is simple - just cut and paste the following line in place of the existing one:

CwSegments=1800000-2000000,3500000-3600000,7000000-7125000,10100000-10130000,14000000-14150000,18068000-18095000,21000000-21200000,24890000-24920000,28000000-28300000,50000000-50200000

When you do so, be sure that your e-mail program or text editor hasn't accidentally added any carriage return characters, because that will royally mess things up. Save it, and re-start SkimSrv.

A careful reader may have noticed that we've increased the CW segment on 10 meters to 28000-28300.  The reason for that is to allow you to set two center frequencies on 10, giving you the option of listening for the 10-meter beacons that operate between 28200 and 28300.  To do that, add a second 10-meter center frequency of 28209 to the CenterFreqs192 line in the .ini file.  With 7 bands, you will be able to cover the 6 contest bands plus the 10-meter beacon band.

I can't find my SkimSrv.ini file!


No problem. In Windows XP, it is in the SkimSrv folder of the Afreet folder, under Program Files. In Windows 7, it is found in C:\Documents and Settings\(user)\Application Data\Afreet\Products\SkimSrv, where "user" is the username you used to log on Windows.

What about non-contest periods? Do I have to remember to change back?

Nope. During non-contest periods, the RBN Server will set excluded frequencies to take care of that. Spots inside those bands - essentially, the normal RTTY segments - will not be sent to the RBN, just as if you still had the original CW segments line in place.

Help - it overwhelmed my Skimmer computer. What can I do, quickly?

Go into SkimSrv's Skimmer tab and reset your Skimmer bandwidth to 96 KHz. That will give you coverage of the first 90+ KHz of each CW band, and you will probably get 98 percent of the spots you'd get otherwise, but your computer loading should be usefully lower.  Alternatively, you can reduce the number of bands you are covering, and see if that is enough to get you by.

1 comment:

  1. Has anyone managed to run skimsrv.exe with a funcube dongle pro plus yet? I've been trying, but it's a no-go so far. I'm guessing it won't work.

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