There are two explanations for reported frequency variations unless they are
reported at EXACTLY the same moment in time--rx error or tx change. Many run
stations, myself included, if that less than perfect run frequency becomes
even less perfect we will adjust the tx frequency ever so slightly to try
and get in the clear. On the next CQ after that another skimmer may pick up
the new frequency and report that as a new spot or it may be interpreted as
the same spot but a different frequency. Saw that in ARRL DX CW when I
shifted frequency while running at NY4A. Not sayin' one way or the other,
but consider all possibilities.
73,
Jim, K4QPL
----- Original Message -----
From: "Pete Smith N4ZR" <n4zr@contesting.com>
To: <vr2bg@harts.org.hk>
Cc: <cq-contest@contesting.com>
Sent: Monday, February 25, 2013 9:35 PM
Subject: Re: [CQ-Contest] Summarizing the Skimmer Accuracy Thread
Bret, send me your data in a form I can look at, and we can have a useful
discussion. I can imagine several scenarios for what you describe -
harmonics, dueling CQs, keyclicks, and so on.
I'd love to see your data. Your assertion about 1-2 percent errors is
totally out of the ball park. The RBN made 3.7 million spots during ARRL
CW - are you really saying there were 37,000-74,000 erroneous spots? Show
me!
73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.
On 2/25/2013 6:33 PM, VR2BrettGraham wrote:
Here is some more data. On 2012-09-21, there were 151 RBN spots of the
same call but on another frequency >3 kc away on the same band at exactly
the same time (to the second) as another skimmer spot. For this query, I
can avoid "dupes", so opening that up to spots of the same call >3 kc
apart on the same band within about 9 seconds of each other finds 369.
That is just one mechanism. Spots of same call on different band on the
very same second look to have been 140. That's already 0.3% of RBN spots
that day & that will exclude a LOT of wrong-band spots. Add busted call
spots & who-knows-how-many busted call wrong-band or wrong-freq spots &
then scale all this up by some factor as activity is much higher on
weekends (I'm working with weekday data here, as it makes it easier to
find wrong-band spots as no multi-multis on then) - I believe RBN could
be blowing 1-2% of what it spots, perhaps more.
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