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Author Topic: CW 6933 2115 01/03/2013  (Read 1416 times)

ETM71

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CW 6933 2115 01/03/2013
« on: January 03, 2013, 2120 UTC »
CW 6933 2115+ 01/03/2013; Mostly groups of five letters w/ a distinct "++" then "NNGTN" repeated five times at one point, still in progress @2121; "+ + + IWNDA DWNDA DVNDA DWNDA DLNDA" @2123; Ended w/ a "+ + T" @2135

Note: Having fun with a just installed MultiPSK.
« Last Edit: January 04, 2013, 1406 UTC by ETM71 »

Offline mr. mike

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Re: CW 6933 2115+ 01/03/2013
« Reply #1 on: January 04, 2013, 0219 UTC »
So was it somebody doing CW tests, or some sort of intelligence exercise?
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Offline ChrisSmolinski

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Re: CW 6933 2115+ 01/03/2013
« Reply #2 on: January 04, 2013, 1149 UTC »
Sounds like the cut numbers sent by Cuba (M8).
Chris Smolinski
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ETM71

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Re: CW 6933 2115 01/03/2013
« Reply #3 on: January 04, 2013, 1412 UTC »
Question: When you're dialing in something in CW, how do you know what frequency is the "right" one to center on? And does it matter to a Sigmira, MultiPSK or other decoding app? I would guess there's an optimal (standard?) audio frequency to the tone, right?

Thanks
Erik

Note: It seems that while using the receivers CW mode (and some fiddlin' with the filters) there really is only one frequency. Ok, ignore my dumb question above lol. AND thanks Wiki's "Morse Code Abbreviations" page lol.
« Last Edit: January 04, 2013, 1431 UTC by ETM71 »

Offline Token

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Re: CW 6933 2115 01/03/2013
« Reply #4 on: January 04, 2013, 1546 UTC »
CW 6933 2115+ 01/03/2013; Mostly groups of five letters w/ a distinct "++" then "NNGTN" repeated five times at one point, still in progress @2121; "+ + + IWNDA DWNDA DVNDA DWNDA DLNDA" @2123; Ended w/ a "+ + T" @2135

Note: Having fun with a just installed MultiPSK.

This does indeed sound like cut numbers, and might well be Cuban M08a.

One thing to remember when using software to decode CW is that no software is infallible, and the lower the signal to noise ratio the more errors even good software will make.

Your + signs are probably actually Morse code digraphs AR, the + sign and the digraph AR use the same dits and dahs, but AR is generally the translation in this application.  + is seldom used in CW, while AR is a frequent shorthand for stop copy or all received.  Writing it as + is not wrong at all, but can be confusing to some.  Also, if you were to look for a description of M08a it would define this as AR, not +, and might mislead someone who does not know they are the same character.

Other errors in the example you have posted.  These cut numbers use the pattern ANDUWRIGMT = 1 to 0, example is A=1, N-2, D=3, U=4, etc to T=0.  As you see from that there are no L or V, but your copy shows each used, this is most likely an error on the part of the software.  Possibly a dit or dah from the character before or after was incorrectly parsed to that character.

With software decoders and signals without large signal to noise you can often record a few minute segment of CW and play it back repeatedly, getting slight variations in the transcribed code each time.  The higher the signal to noise ratio the better the transcription is likely to be.

I try to tell people who do not copy code by ear that software decoders are a nice tool that can give you a general idea of what is being sent, but treat it like something you read on the Internet, it might not all be there, and sometimes it is an out and out lie.

T!
T!
Mojave Desert, California USA