[RTTY] Decoder performance on crowded bands

[Larry]

I saw several cases where the leading and/or trailing character of a call 
sign got clipped. Perhaps the skimmer is seeing something like that. We have 
had the discussion many times about how to minimize the chances of such 
clipping.

73, Larry  W6NWS

-----Original Message----- 
From: Salvatore Irato
Sent: Thursday, October 01, 2015 8:32 AM
To: rtty at contesting.com
Subject: [RTTY] Decoder performance on crowded bands

Oh YES Lee!
All this make it very clear, I suppose that from who is the originator
of the entry there could be applied any further check about the
skimmer in use.
Perhaps what seemed to me is wrong ... but anyway I was, not
analytically, looking at the first file and those entries catches my
eyes  ...
-snip-
26-Sep 0041Z IW1RUA       14095.1 IW3RUA        9 W3OA-# RTTY
26-Sep 0041Z IW1RUA       14095.1 IW3RUA        8 W3OA-# RTTY
-snip-
26-Sep 0041Z W1RUA        14095.1 *No License*  0 W3OA-# RTTY
26-Sep 0041Z W1RUA        14095.1 *No License*  0 W3OA-# RTTY
-snip-
(I don't remember what is one digit number before the skimmer callsign
... quality?)
Him was IW3RUA, I am quite sure. Forked also it as was for W1AYD that
I have seen many times on my same QRG over the bandmap lately ... :-)
BTW IW1RUA doesn't exist ... to my knowledge of IW1 licensee.
Out of yours excellent work and information, Lee, I would think that
there is some "smuggling" ... or a very fringe path specific to that
case.
In your case, Lee, those W1 calls didn't get the way to be cluster
wide relayed. But sometimes as I have seen W1AYD it may have followed
another patch, a "smuggling" path, isn't?

Really not that problem as it could be the way as GRITTY or/and an
experienced operator may "brain filter" the bandmap. That's part of
ours personal operating style and possibly of software integration.
Each are not that easy ...
Not all the rules could be stoned, not all the stoned rules are the
best. Software and statics sometimes may not be on the same way. Just
in case.


                       73 de iw1ayd Salvo


PS Jumping to other topics ... There are two more questions, that I
may triggered, but those already received responses. Still I would
like to ad some words on the subjects ...

The {ENTERLF} is coming from ASR as I am and it is more appealing for
me ... isn't? Taking care to rule that small lever on the left
"bumper" of the latest models, i.e. ASCII ASR33.

The tail ending CQ is also appealing as I say after my call that I am
CQing, not responding to anyone. Who is coming onto HAG21AYD IW1AYD
could equivocate on what I am doing there.
The same as for the TU: HISCALL TU IW1AYD CQ. I am ready for another 
contact.
Not QRZ, as I need fresh call in, no idea or store of anyone other.
Having it I will coming back
with TU NOW ...

So I have to agree with Don, from witch I learned the most in the hope
to apply it right, Rick, that helped me a lot of times, and others
from witch I constantly learn here.

> Message: 2
> Date: Wed, 30 Sep 2015 19:19:01 -0600 (MDT)
> From: Lee Sawkins <ve7cc at shaw.ca>
> To: rtty at contesting.com
> Cc: dezrat at outlook.com
> Subject: [RTTY] Skimmer spots dropped at VE7CC cluster node
> Message-ID: <716460089.84737880.1443662341911.JavaMail.root at shaw.ca>
> Content-Type: text/plain; charset=utf-8
>
> These links may be interesting to some of you. These are the typical 
> rejected spots of any CC Cluster.
>
> RTTY skimmer spots are considered valid if spotted by ONE Skimmer. RTTY 
> Skimmers are generally more accurate than CW and there are simply not 
> enough of them to use 2 or more Skimmers to validate them. CW spots are 
> valid if spotted by 2 or more Skimmers.
>
> Here is the list of dropped Skimmer spots by the VE7CC-1 cluster.
> If you connect to the RBN directly, you will receive all these spots as 
> well as the good ones.
>
> Many times there are two calls in succession that are dropped for RTTY 
> calls. I am receiving data from both the RBN and DL4RCK for redundancy. 
> Usually they both spot the same RTTY calls.
>
> Most columns are self explanatory.
>
> The number directly before a skimmer call is a quality number. It is the 
> number of times a call has been detected as correct minus the number of 
> times it is busted. When the number decreases below 5, it is no longer 
> considered valid. If the active call has not been spotted in 12 minutes it 
> is also no longer considered valid. In one place, for 9A1A the quality 
> number is over 2000. This means 9A1A has been spotted over 2000 times on 
> the same frequency!
> "Sysop added" means I have manually added a call to the list because it is 
> busted all the time and is never good.
>
> http://www.bcdxc.org/ve7cc/ccc/Busted-26-Sep-2015.txt
> http://www.bcdxc.org/ve7cc/ccc/Busted-27-Sep-2015.txt
>
> Lee
>
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