CW Decoding

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  • Updated 3 years ago
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Yep, I know we can get this through a 3rd party product - CW Skimmer -- but with the ICOM 7300 and Elecrafts providing this natively, why not add it to the feature list of the 6000 series as well?  It would be so cool to just click a tab and have a CW decoding window pop up at the bottom of the screen.
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Posted 3 years ago

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Photo of Al / NN4ZZ

Al / NN4ZZ

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Good idea....there is an idea to add spots from CW Skimmer to the SSDR display....

Adding a decoding window is a good addition and I added your comments there too.  (hope it's okay)

Here is the link:

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
6700 - HW.................. V
SSDR / DAX / CAT...... V

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Walt - KZ1F

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That was actually part and parcel of a question I asked the other day that now I had the DAX audio now what? That was actually a multipart question as it isn't clear what one doublet of information represents, is it temporal or spatial? In other words, is it a point in time and/or is it a point in space?  I am thinking it is a point in time (temporal).

We tend to think of a spectrum display having real estate or an oscilloscope showing a wave over time but, as I pondered this question I concluded it is a sliver of time where the trace would be over time had it had a X axis.

I am thinking therefore that two channels is likely superfluous as are, for the sake of CW, the negative values. Collecting what's left over, and time stamp them, we'd have a series of amplitudes, some short, some long, some really long. The really long spacing of low amplitudes is the inter-word spacing, the really short lived high amplitude values are the dots and the intermediate lived high amplitudes are the dashes. Then just look up the values! Where one could get creative is in filtering out noise and adjusting for legacy keyers. I did try to google to see if I could find published articles on signal processing. As I believe I mentioned to Howard, I really enjoyed physics classes but never took the advanced ones where I am sure this sort of subject came up.                                                                                                                 
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W5XZ - dan

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like, some software than can pull cw out of the noise better than the human ear?

73, w5xz, dan
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WW1SS - Steve

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I would like it as I have some hearing loss and have a hard time with it.
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Walt - KZ1F

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Ag1le blog - OK, I feel a decoder in my future., I don't believe my previous is entirely correct. The DAX signal represents everything in the passband. In the case of a 100Hz CW filter, yes, one can conclude there is but one discrete signal there but, let's say you opened it up to 3KHz on 14.070 (or .100) for psk. In that case there are more than one active signals such that, over time, multiple concurrent signals will be oscillating around 0. My head is about to explode.
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James Whiteway

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I thought real hams knew code ! No need for a decoder!
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Ken - NM9P

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Many hams know code, James.  
I even passed 20 wpm the hard way, after years of frustration and fighting, no less...

But just last night I was trying to bust a pileup on 40 Meters, and the guy was sending at 45 wpm!  In my book, there is not reason in the world for a DX pileup to run that fast.  I couldn't even have copied my OWN call at that speed.
That is why I would like to find a top-notch decoder to assist my CW skills.....
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Rick Hadley - W0FG

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You must mean TU5MH.  He was actually running 38-40 wpm.  I speed matched him with CWX and got him at 02:14. I can't carry on a full QSO at those speeds, but can copy calls.  Very unusual to find a DXpedition running at those speeds, but it may have been a way for him to reduce the pileup.
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There is no CW decoder that I found that is accurate enough to be embedded into the Flex radio.

To me, a skimmer show's who's out there and, only secondarily, what they might be saying. I think skimmers take advantage of one of the same features the human brain uses to decode a fast contest or DX exchange... anticipation and format. Adding skimmer capabilities to SmartSDR seems to fit very nicely. Relying on the radio or SmartSDR to decode code, less than useful fit.

In a DX exchange I expect to hear my callsign and 5NN. Send it at 50+ WPM and I can still pick out my callsign and the RST because I expect to hear it and I hear the format the DX station is using. I couldn't have a conversation with the DX station at those speeds but then again, everyone else in the pileup probably appreciates that.

I have not found a single decoder (cw-get, skimmer, KX3 built-in, and various commercial and homebrew hardware kits) that have not actually impaired my ability to copy by ear because of their inability to copy anything but a perfect signal.

Congrats on TU5MH Rick.

It's just me.

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Ken - NM9P

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Rick, perhaps it reduced some of the pileup because so many may have given up.  But it probably also added some to the congestion because so many people could not be sure what call he was sending and continued to throw theirs in just in case...

According to Reverse Beacon Network and he was anywhere between 40-45 when I was trying to copy him.  I don't know how accurate RBS reports are.  In any case, it was faster than I ever hear on 99% of the DX pileups, especially on the noisier lower bands.

The combined effect of the high speed, weighting/ratio he was using, rapid fading, noise, and water/auroral effect on his 40 meter signals, the high speed code was extremely difficult to distinguish at my QTH in Southern Indiana.  

I have fought many contests and DX pileups in the 28-35 WPM range successfully, but this was a particularly difficult copy.  I eventually gave up with plans to try again when the lightning is further away.....perhaps after working the big guns he will slow down to about 32 wpm, which I have read many places is about the optimum compromise between speed efficiency and needed repeats due to excessive speed.  Others may differ on that point.

Ken - NM9P
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Rick Hadley - W0FG

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I have to agree with Elroy.  I've never found a CW decoder that worked well on anything except computer generated code.  As noted, CWS does a pretty fair job on callsigns, but I consider it unusable for anything else, which is OK as CW was always designed to work with  As far as TU5MH goes, I had pretty good band conditions and found him remarkably easy to copy, given his speed.  I had plenty of time to listen to him, as I'm just running barefoot to a vertical on 40, so it took me a while to snag him.

Rick, W0FG