[Skimmertalk] Fwd: Re: Identifying CQ-ers

[Pete Smith]

Excerpts from an e-mail just received from Alex.

>Delivered-To: n4zr at contesting.com
>From: "Alex, VE3NEA" <alshovk at dxatlas.com>
>To: "Pete Smith" <n4zr at contesting.com>
>Subject: Re: Identifying CQ-ers
>Date: Mon, 17 Nov 2008 10:31:04 -0500
>
>Hi Pete,
>
>
>>Hi Alex - I don't know if you have been following the discussion on 
>>Skimmertalk. K5QQ ran some tests during CW Sweepstakes


>>....K5QQ did not tell us what validation option he used - this setting 
>>has a significant effect on the identification of the running stations. 
>>For example, in the Minimal mode the call is spotted after its first 
>>occurrence if it is found in Master.dta. Consider this scenario:
>
>- N4ZR TEST
>- VE3NEA
>
>Since VE3NEA is in Master.dta, and it appears immediately after TEST, it 
>may be spotted as running if Minimal validation is selected. This depends 
>on many factors, such as the time interval between TEST and VE3NEA, and 
>the number of times N4ZR was previously copied on the frequency, but the 
>errors will occur from time to time. The Minimal  mode is more appropriate 
>in the pileups than in a contest.
>
>If the running station always repeats the caller's callsign, as in SS, 
>this type of error may occur in other validation modes as well, since the 
>Skimmer decodes the callsign of the calling station twice.
>
>
>
>>I have always had the impression that if anything Skimmer tends to false 
>>negatives.  For example, if a rare station is running and signing his 
>>call but only sending "UP" or "TU" then Skimmer doesn't realize he's CQ-ing.
>>
>>I wonder if you can elaborate on the rules that Skimmer uses to 
>>identifying someone as CQ-ing.  I know about "CQ" and "TEST" and (I 
>>think) "QRZ", but what else is there.  Does Skimmer in any way look at 
>>callsigns identified on a given frequency within a given time period 
>>after one of the "tag" words?
>
>CW Skimmer looks at the keywords before and after the callsign to 
>determine its CQ/DE status. Here are the rules:
>
>  //forward: {CQ,QRZ,TEST, SS} [garbage] [DE] <call>
>  //backward: <call> [garbage] {UP, TEST, SS}
>
>
>{} = any of
>[] = optional
>
>
>Garbage is one or two words that may appear between the keyword and the 
>callsign, i.e., in "CQ DX DE <call>", "DX" is considered garbage.
>
>Note that pattern matching does not work across the pauses, so that in the 
>messages like "<run_call> TEST <pause> <sp_call>" there is no association 
>between TEST and <sp_call> if the pause is 0.5 s or longer.
>
>
>
>>One theory being discussed is that because the CW Sweepstakes exchange 
>>requires each station to give the callsigns of both stations, that both 
>>stations in any given QSO are being identified as CQers, but one is 
>>moving on.  Is that likely?
>
>We do not have enough information to tell what exactly happened in K5QQ's 
>test. If he made an I/Q recording while checking the spots, he would be 
>able to play it back and see what exactly was copied, why the callsign was 
>posted, and why it disappeared by the time he tuned to the frequency. I 
>hope in the future tests the people will make such recordings and will not 
>have to speculate on the results.