Blogospheric expansions on some of the same tabs you saw before making the mistake of clicking that last tab!

 

 

Blogospheric version ... Let's define the term.

Caution: economy has been thrown to the wind on the tabs of this page!

 

Well, Wikipedia and ARRL both say "Continuous Wave" signaling. Interestingly, with regard to CW, FCC says nothing about "... wave" in Part 97. Nothing. IMO, they know better, and so they just call it CW and are done with it!

My take, as an EE in digital comms as far back as 1973, is that CW is best left as a two-letter tag, a la FCC. Why?

Technically, CW can mean several things. One is interrupted carrier wave (or "ICW," described as most precise in the Wikipedia entry for CW no less), and that's not too bad, but too coarse IMO, not to mention the fact that no one literally interrupts a carrier (illegal clicks galore). When a carrier (or power-present/ON symbol) goes non-zero in a legal way, it always does have some controlled symbol shape, in which case it is a form of AM, just as declared in the ARRL Handbook for Radio Communications. It is also, at the EE comms level, a form of ASK - amplitude shift keying (of a carrier, in this case, and from zero to max amplitude to boot, but shaped in all but the first equation in the textbook). But few hams call it that. It is also a pulse duration modulation (although a very inefficient one). All well and good so far, but the AM aspect belies ARRL's definition of single sideband, which they also call a form of AM, and which is, most definitively, not pure AM; see comments on SSB in these pages. In any event, CW can also be a form of baseband audio-on-SSB, which is actually the usual case these days; see ACW? on this page. If modulated as a tone-on-SSB, CW is actually FCC mode J1A, but no ham (well, no one I know of) would ever call it that, even though that's precisely what it is.

BTW, when you "receive by ear" a CW transmitted as J1A, you (or even a CW decoder) can't tell it apart from a CW transmitted in any non-SSB way. J1A and A1A are indistinguishable at a receiver. So why bother with J1A anyway?

With Continuous Wave, Wikipedia and ARRL declare CW, implicity, to be a form of carrier-supported transmission, in other words, radio. Of course. But that's because they define a continuous wave as, just, an electromagnetic wave. They reject the notion of Carrier Wave, which would also do the trick and probably do it better.

Telegraphy sans radio carrier is not CW, it's just telegraphy, a baseband over some sort of wire. Baseband, and not DC, because on-off DC current has a zero-centered finite width spectrum!

Whatever it is, CW is only radio telegraphy; i.e., wireless. CW's baseband audio spectrum is moved well off of 0Hz (yet still bearing two symmetric spectra either side of 0Hz, as required for any real signal. Now, just to say, I'm not mis-describing SSB, a very real signal with an asymmetric spectra around fc (a suitably high RF center frequency), not zero Hertz! All physically real signals, including SSB, are exactly symmetric around 0Hz! Fourier analysis 101.

Now, there is the history of CW, and not everyone's an expert. Not YT for sure. And history is written by the survivors (some say the winners). So there are bound to be missing nuances, missing players, missing dates, heck, entire missing chapters. I put together a bit of it, as I read it upon finding it here and there, at the History tab.

That said, CW is the very simplest thing we can do in ham radio, yet utterly sublime. But simplicity has its costs. Take word rate. Ordinary vocal speech in English conversation averages, according to the National Center for Voice and Speech, between 120 to 150 WPM. This may be far less than in some other languages! We know that CW receive by ear (FCC mode 150HA1A), not to say send, is apparently routinely demonstrated up to about 75 WPM*, or half that of vocal conversation. So patience is automatically a plus, especially at 13 WPM (the old General Class test rate). Even at 20 WPM (the old Extra Class test rate). Perhaps CW is a sort of patience, as well as concision. An historical epiphany: the very first Morse code ever sent by radio (across a whole two miles by Marconi) was the message "A patient waiter is no loser." Yep, patience in the very beginning. And obviously bucks.

FCC Part 97, under which we hams live, has a whole list of emission designations, and CW can be A1A or A1B (the latter being CW decoded by machine, a possibly popular way of copying ham CW when too fast for the listener).

Some hams toss patience to the wind. And receive Morse not by character, but by entire words and beyond. This can be very fast. The brain must be rewired in some way to do it. But that can be done, and thousands have.

With Q codes and abbreviations, the swiftest CW may even outpace spoken conversation. But the vast majority of us live at 20 WPM or less. Just check Vibroplex's(TM) Certificates of Code Proficiency: most every month, 2/3rds are at 20 WPM or below. Proficiency may be cumulative, but Certificates dry up fast beyond 25 WPM. Probably the vast majority of us settle for 20 WPM. Even with word compressions, that's not even 1/3rd the spoken rate. But CW hams love it.

 

* Now consider the Guinness(TM) World Record for Morse transcription onto paper using a manual typewriter, set in 2005 Down Under. (I used an Underwood screwed down to a metal table on a big ship in 1969, struggling along at 18 WPM, with definite spelling errors and occasional gobbledegook for missing words - that latter maybe even dangerous at sea, but it happens.) There is a Guinness Record for receiving at 26.7 WPM! How can that be? You've met hams who QSO at 25 WPM, even in QSB, QRN and QRM! And more than a few who claim 35 or 40. And you'll read about crazy speeds (see below). Well, it's the brain on turbo boost, hands free, not to mention our mostly short, conventional messages. What a multiplier, this thing called human intelligence and experience! This overall thing called skill. However, if, for the Record, a perfect copy of only random 5-tuples of alphabetical characters (and numbers!), a sound and fury signifying nothing, not ziltch in ordinary English, is required, typing it all out, for verification, on a manual typewriter, you will not find anyone who can do, say, 27 such "W"PM error-free, for even a minute! No one. It appears to be simply beyond human ability. (But not even a modest microcontroller!).

Now, transmitting, one very good wrist set the Guinness Record for transmitted Morse code at 50% faster than that received code record. This was also, oddly, back in 2005. Maybe these records were so far out, no one's even tried to beat them since.

All that said, brain turbo-boost does seem to support radically-fast "plain text" Morse, one such report in 2008 being 140 WPM. On an electric typewriter, for one minute out of five. And this same guy said there were some European hams hitting 200 WPM. Not sure if that was typed out, but it could have been, as the current World typing record is about 256 WPM. But for full character sequence uncertainty of what's being sent, i.e. at maximum information rate, no way! Any of that.

 

 

Blogospheric version ... What the survivors tend to say.

Economy to the wind, continued.

 

We must start with wired comms. And it all happens in early USA, strangely enough. We tend to give Brits, Germans and an Italian guy credit for most everything in early radio. Except CW!

The first serially-coded (I read this as the "modern" scheme of one character after another, etc.) electric scheme was the single-wire American Morse-Vail telegraph (1851), a better mouse trap than the English Cooke-Wheatstone telegraph (1837), which pointed needles at letters. The actual date for the first wired telegraph Morse (probably pre-Vail's improvement, see below) was 1844. So it took some time to standardize what we use today.

Now dive a bit deeper about the actual standard. Samuel Morse was a Yale grad and fine art painter, but also an inventor, and perhaps something of a rascal. In any event, Morse, teamed with Leonard Gale, a chemistry professor who was buddies with the great American physicist Joseph Henry, and a young entrepreneur named Alfred Vail (along with his brother George and their dad's money), developed the single-wire telegraph. Morse took the source coding lead and invented a codebook scheme based on (up to) four-tuples of numerals to transmit whole words. Morse used, and did apparently invent, the sequence of key-closure symbols (dits and dahs), probably 4 of them per each numeric digit (0-9) as the most basic level in his codebook scheme, unlike the 5 dit/dah symbols per digit of today's coce, to represent the ten digits. Then four of those digits, assembled in sequence as a uniform-length, single "codeword." This encoding of numbers (each 4 digits in length) to entire words is clumsy, not very expansive and inflexible. While it did allow for the arranging the likelihood (of a word) to the shortness of length of its codeword, like modern Huffman coding, it was still a two-step process to get actual words out of the dits and dahs, first receiving those as a 4-digit number, then using that number as a look-up index into Morse's (very long) dictionary. Vail saw this shortcoming and fundamentally modifed the code to directly encode the individual letters of the Latin alphabet (a-z) as well as the ten digits (0-9). This was the key improvement. Basically, Vail discarded the entire symbolic number-to-dictionary word codebook scheme in favor of a simpler symbol-to-alphanumeric character (and, extended, to punctuation marks as well) codebook, or what you'd call just a direct code. A very, very short code. The one we learn today. And once you've learned merely forty odd dit-dah symbols (from 1 to 5 making up a single character), you can then encode or decode anything! It's Morse's four numbers (each encoded) for a word by lookup versus five similar-length symbols for an average-length word. (Yes, non-average length words take more dits and dahs in Vails's scheme, but who cares?) It's no contest! No one could ever hope to equal Vail's scheme with a Morse-like dictionary of even a thousand words, let alone the 11,110-odd words potentially in Morse's original dictionary! Not that we hams commonly ever use more than a hundred words (in CW)! But then there's data stuff like temp in F, and so on. It doesn't take long to convince you that Vail's idea is vastly superior.

Now, someone will say Morse's scheme becomes superior (for sending text from a surrealist novel like Gravity's Rainbow) when a computer is in the loop. Yes, source coding (compression) is amazing. And digital memories can trivially hold the entire Oxford English Dictionary. But there were no digital computers back in Morse's day. Such a thing might have been an imaginative happening in a Steampunk novel like The Difference Engine, but it did not most definitely happen until Turing and the mid 1940s, culminating in certain electron tube experiments with programmable machines at the University of Manchester in 1948. (We ought note that there were earlier analog computers, used for artillery aiming and bomb dropping in WW II, but it would be a stretch to imagine them deployed as a dictionary look-up table - although this is, in fact, possible, just ludicrous.) So forget it! Morse's scheme was ridiculous, and Vail's reinvention of Morse's dits and dahs was genius.

This Vail encoding (minus many modern additional punctuations, prosigns and such) is the code we know today. Yikes. You could, maybe, say that Alfred Vail invented the code we send as CW today with Morse as a mere inspiration. No codebook! Character by character, word by word, right off a page of verse in the Latin alphabet. (Chinese or Japanese would prove to be very much harder to adapt to Morse code, or QWERTY keyboards for that matter.) Alas for the Vail brothers, Samuel out-flanked 'em and took it all in a "reorganization" of their partnership based on obtaining new US Government funding! (Don't ever say government isn't the secret sauce behind so many entrepreneurs!) Alfred, for reasons that remain controversial today, backed off claiming any ownership to the code and died, pretty young, in 1859, never to see it used in its full glory (in, for example, the Civil War). Maybe there's a mystery novel there. Most everything in America at that time was very much up in the air, and there never was a serious challenge to the emerging moniker "Morse code." Single wire would soon expire, but Morse's name stuck to Vail's book-less code like glue. Vail's idea emerges around 1851, its debut in practical if experimental telegraphic use. But after 1860, it saw rapid adoption all over the US, Britain and Europe. Now, switch gears to radio. We're not writing a novel here! But considerable word gluttony!

The first CW was Marconi's Morse code "wireless" 6 km demo (1887), eventually stretched by hop (skip and jump, a wondrous mystery) across the Atlantic (1901). It was spark-gap radio; you couldn't even say it was a frequency, but it wasn't DC! The rest, as they say, is history. The Nobel Prize, IEEE Medal of Honor, etc. Marconi inspired the eponymous British radio company and its American affiliates well before he emigrated back to his native country for later, less inspiring works.

Two-way, trans-Atlantic commercial CW became reality fairly late, in 1923, but could not compete with undersea telegraph cables, which had been reliably in place since 1866. CW seemed destined for places without wires. Like islands or on ships. Even planes. But not yet rockets, actually never rockets or any spacecraft so far as your reporter can tell! Yet, CW would continue to play a role in warfare supporting cryptographic transmission by combatants on both sides in WW II. Famous among these were the Enigma networks and counteroperations by daring Resistance hams in Europe.

By the '50s, CW had, for all practical purposes, been retired from military use. (ARRL's version insists on 1988, but as a ripened comms engineer by then, I simply cannot imagine that except as in historical demos or the like. Military comms was almost all digital by 1980, and what was not (i.e., not message- or code-book, nor sampled voice) was probably almost all RTTY by even 1970. And recall the iconic CRM 114, most definitely way beyond CW, in 1964's Dr. Strangelove, or How I Learned to Love the Bomb - Stanley Kubrick didn't invent that idea, he borrowed it! Yet still, totally bucking the trend, CW was kept on life support in the Merchant Marines of various nations, by radio officers pounding away on shifts, versus RTTY machines clattering away in closets. (And there certainly were RTTY machines on most all large ships in the '60s.) But even that's not the CW ARRL must be referring to in 1988. A long-ex-Merchant Mariner RO myself, my Chief RO would not let me touch that RTTY locked away in a closet of the radio room! Anyway, CW is still used today in shipping, but very rarely - maybe when everything else is down, the mode of very last resort. And the US Coast Guard had its ZUT (a club of USCG Operators, Zeta Upsilon Tau - go figure the greek*) with practical CW shipboard use up to at least 1996. Way beyond 1988. But I wouldn't call the USCG military, and neither would they!

Aside from esoteric use, throughout all those decades, radio amateurs kept the waveform alive for sheer fun, its simplicity and prowess for chasing DX in channels that simply wouldn't support AM, or from places a '70s RTTY boat anchor (weighing in a 100+ lbs and sucking many hundreds of watts) might have been scarce, like Pitcairn Island for example. Even SSB ham radio phone coming on strong in the '50s could not match CW in weak propagation. It's simple: all else constant, it's a bandwidth ratio beyond 10-to-1, or 10+ dB favoring CW over Phone for QSLs "in the weeds," not to mention the serious decoding power of the brain. Hoping you didn't just imagine that QSL! Maybe that's one reason CW is still permitted in the US (at least) anywhere in any ham band. (All the while noting the restrictions on 60m and the no interference to non-amateur uses limitation on various other bands!)

But beyond all that, it's a Zen-like art and sport that's just got to be King somewhere. Like archery!

 

* Zeta: a society or fraternity, Upsilon: a ratio of mass to light energy, popular (if you could call it that) in physics, Tau: a hieroglyph, originally imported from ancient Egyptian by the Greeks, meaning "mark" (of all things), "space" presumably being what marks exist in. Everything has to exist in something, no?

 

 

Blogospheric version here is just the same as that other page you just came from.

 

Looking for practice at various WPM? Here are some convoluted links for CW Op(eration)s.

Then there is the CWops gang itself, to which the swifter may be magnetically drawn.

For fun and myriad suggestions, a nice piece from Gary, ZL2IFB, is The FOC Guide to Morse Code Proficiency. I notice that Gary has his paddle on a anti-slip pad. They do slip around at just the wrong moment!

There's a much older, but not necessarily moldier, treatise on CW that's worth a look. Half psychological (take that as you like), the other half is filled with history and good practical stuff. I particularly liked Chapter 6.

 

 

Blogospheric version ... Now this is getting esoteric. Wanna pass?

 

CW was, way back, just an on/off connection of power to a Class C amplifier, through an RC low pass filter to dampen the clicks*. Driven of course by an RF sinewave that just sat there on the grid. I doubt there was ever an analogous mode on AM for at least one obvious reason, that being the low efficiency of a linear amplifier required for AM in general. Still, you could key the gain (in that case, a level shift from zero up to max) of a linear amplifier to get CW. Now this is an odd thing, but carrier-keyed CW is a DSB signal! Hey, it's just DSB-C without higher (i.e., voice) baseband spectra. Key clicks then produce broader spectra because AM amplifiers let ~ 0 Hz to ~ 2.8 kHz of audio through. And you would still need a BFO to receive this weird CW/AM thing, just as you would straight CW.

When SSB became commonplace in the late '50s, someone probably casually invented tone-on-SSB CW, with its sideband demodulation back to an audible note in your ear. Does anyone know who this pioneer was? The resulting CW/SSB thing became a de facto commercial rig standard long ago, even by the '90s. However, no one, to my knowledge, ever called this "synthesis" (transmit), as opposed to "analysis" (receive), of SSB CW anything but "CW." Now a few of you may feel the urge to say that CW/SSB - just because it's SSB - has half the occupied bandwidth of ordinary (non-SSB) CW. Using just a bit of imagination, you can see that CW/SSB has exactly the same bandwidth as ordinary, direct carrier-keyed CW. It better, or we'd need an AM demodulator! And we never did. The key bit to recall is that the only thing suppressed (other than an unmodulated carrier component) in SSB is the mirror image, the other sideband on the opposing side of RF center frequency fc. The CW keyed tone, along with both of its significant (audio) sidebands are far enough away from that fc, we hope. Well-groomed SSB passes all audio that's fit to pass. If you argue that the CW audio sideband closest to RF fc may actually overlap it, then there is a problem! Will it fold back on itself on reaching the "wall" at fc, or will it just vanish, either distorting the CW audio? This has a simple answer - go figure. And this would have serious consequences for (odd spectral order) key clicks, if the SSB transmitter allowed those, but a well-designed one won't (by using an audio bandpass filter to kill all that off and stay within FCC, and I presume ITU, limits). So not to worry unless you're going with "pure amplifier keying," a la 1960 or even later.

Now, digital modes can (although it is only one option) use audio (typically analog at the rig's connector, though I/Q interfaces have been around for almost 20 years) to make digital waveforms like FSK, PSK, etc. When that's done, some hams stridently pronounce the RF to the antenna as A-this-or-that, e.g. AFSK for "audio FSK." We know that, with high audio SNR and decent SSB generation, there's no discernable performance difference between directly switched fc and this analog/SSB thing, i.e. "canonical" FSK versus the latter. I've confirmed this with the author of these modes for the ARRL Handbook. (And many of us know so from EE501.) That author commented that the AFSK aspect only described the keying interface into the SSB transmitter and not the final output into the antenna. This limitation on the use of the acronym AFSK drives some hams wild. They want their AFSK at RF!

So if the AFSK RF mafia overcomes the experts, could this CW/SSB thing I've been talking about be more properly called "ACW" (versus plain old "CW")? Is this an absurd splitting of hairs? I sort of think so. But you be the judge.

 

* Some fancy the spectrum display of a CW signal on their modern rigs to comprise a carrier (the seeming high point in the power pyramid), and the rest of it key clicks. Ain't so, of course. That rest of it includes an aspect that comes off as clicks (which some receiver on another frequency, despite their best DSP filter, will hear and swear at!), but in the main it is, simply, the requisite spectral support for a random telegraph wave in time. Only the height of a signal's spectral "sidelobes" describes the onset and extent of the "click." Now we may not transmit randomly, but shortterm, the Fourier spectrum doesn't much care about our intent ... the sampled spectra of CW are just a mashup of dits and dahs rise, hold and fall times. This is the random telegraphy within a discrete Fourier transform window, for instance. As for that central high point - if the transmitted signal is keyed carrier CW, or high quality CW/SSB, there is no central high point! There actually is no 0Hz offset wrt the center frequency fc, or what most hams call "carrier frequency," power! There is no "DC" in any code sequence, none! All the power is elsewhere, i.e. in the lobes, the central main lobe and the sides. This is why, among other reasons, the a "carrier" is really only casually declared or denied to exist in ham radio. In the end, anywhere there's any information present in a radio signal there's carrier energy (contributing to its power spectral density), but exclusive of 0Hz which carries essentially no energy unless it is continuous, non-keyed AM (or FM or PM) carrying exactly one bit of information (that bit being whether there is or is not a signal present)! One bit over large time periods, like over mic key pushed, is a vanishingly small power density, which even then is not at 0Hz but only very close to it!

This very last comment is the wrinkle that puts the ARRL definition, and FCC emission designator, of CW to shame. CW is keyed, it's that simple. AM, by their own acceptance of the term, is unkeyed (except at start and stop, which is independent of the modulation and its information sequencing in time and bears that one bit factor shown above). There really should have been an FCC emission designator belonging wholly and exclusively to keyed modulations, whether by hand key, or digital (say by computer), or hybrid means (say by a keyer). Even RTTY is unkeyed in the continuous wave (carrier) sense. The various definitions of CW that lurk about constitute a true murky backwater. You can be excused from being confused.

 

 

Blogospheric version ... Very esoteric, and I know, you didn't sign up for this. So I totally understand if you just hit the next tab.

 

Iambic or bust? I speak of iambic keying, squeezing the paddles for sequences. Way beyond the Curtis keyer.

Up to maybe 25 WPM or so*, iambic has earned loyal fans. It's a question of just one thing: effort. CW cognoscente will say it's simply not enough gain to be worth it, maybe 6% or so in saved work - I disagree (not all manual work is equal!). While hardly one to judge as I have yet to hit a solidly reliable 20 WPM, I find iambic more comfortable, reducing wrist as well as finger motion.

And all this is not to mention the advent of "forced (inter-)character spacing" offered by some keyers. My rig cals their's Automatic Character Spacing, and it is beautiful ... until you make a mistake, then watch out or better yet just stop! BTW, forced or ACS is not intra-character spacing; this cannot be since the ending of your fingered character input sequence cannot be predicted while within that same character. Digital logic cannot read your mind. Ah, might that be preternatural AI! (Which there isn't, even unpreternaturally.) The only way around this obstacle algorithmically would be to insert a full character delay from hand to band! I assure you, no one will put up with a full character delay - and even if variable, still impossible in a follow-able live stream of keying. Think your sidetone monitor. So, it must be the maximum delay (think the exotic colon, almost unused but still in the character book!), and most esp. awful when the sender is relying on a sidetone monitor made by the keyer! Can you imagine? The one escape clause is for keyboard translators, sidetone-less, but that's not authentic CW ops! (Howls!)

Worse, at some point well beyond a gray threshold, some afficionados say that it becomes physically impossible to iambic key at all! They cite an excruciatingly short time required to come off a squeeze to a full release then back on to just one paddle. Maybe so - you can't have it from me. I do basically break down somewhere between 30 and 35 WPM, but maybe it's just my nerves. (Although I think modern fast sampling of the paddle state can avoid a "squeeze squeeze" by sensing a first instant of touch on the second paddle, implying a "full" squeeze.) But then, and yet worse, they say once you nail iambic, you have to unlearn it to go faster than that gray threshold speed (sniffing at 25 WPM or so) - and that iambic is harder to unlearn than to learn! I'm not actually surprised about that, given how hard I'm trying to unlearn using a Vibroplex bug a half century ago. Deep learning does linger on.

Farnsworth

Now the "and such," that being Farnsworth ... well it must work because so many ops do it! A subspace of its own, Farnsworth keying makes multiple appearances in links. Many, if not most of us, wittingly or un-so, use Farnsworth, especially on paddle-keyer combos. Farnsworth is, IMHO, code-to-brain "transmission ratio-matching" across the rolling hills of CW messaging. I just try to remain true to ISO Morse timing, and simply slow (everything) down when it's apparent for the better. But I find slowing down on a paddle is really hard to do with any fluidity. I cannot go error-free for ten seconds at 13 WPM coming abruptly off 18 WPM. I just cannot.

Farnsworth needs no keyer adjustment! It's definitely easier for me, at least, to open up just the word spacings and keep the WPM keyer rate constant. So the jury is out at this QTH, but there is nothing so admirable as an op who comes back right on pace with his caller, in full standard Morse glory. Beats Farnsworth every time.

I follow my ear. The best code I hear from my receiver is the code I'm after! Svelte, not speed. Steady, accurate timing beats all comers. Personalized keying "style" - you know, those rhythmic weavings about, especially on bugs - can be tough to follow, and perhaps impossible to produce on a paddle. OK, it's creative and oft musical. But what a pleasure to hear a tight, smooth 16 WPM. And it scales beautifully. For the inevitable argument about conditions needing characters to move fast: when we have to, we might best handle QSB by keeping our information lean and mean, vice squeezing Shakespeare into seconds. Straight paddle key iambic is one path to the mountain. Now the straight key and bug folks, contesters and cognoscente, not to mention Farnsworth addicts, go ape at this point!

I understand.

 

* I sense that CWops set their entry threshold at 25 WPM for two reasons. The first, and not obviously, is that the original Extra Class license required demonstrating some accuracy at 20 WPM, and CWops wanted to be a "step beyond." (Even the professional grade Second Class Radiotelegraph Certificate test was conducted at 22 WPM with some tolerance for a few errors. I passed it back in 1968, but barely! I could not have made CWops.) But then, CWops certainly didn't wish to rule out any particular technique - including iambic! So they settled themselves on something less than a nice round number like 30 WPM which some afficionados might assert is "iambic challenged, or impossible" ... uh, 25 WPM being downright iambic easy - hey, even I can reliably key arbitrary text with my keyer set for iambic at 25 WPM, provided I don't have to think about what I'm "saying!" And my CW is chopped liver, as the saying goes.

 

 

Blogospheric version ... I know, this is getting wildly esoteric, but I've deleted the next tab, which was even worse in that respect.

You're at the end of Thoughts, at least mine.

 

Then again, if you're reading on, have you also heard it? Maybe at the low end of 40m?

These stations fire away at 25+ WPM, maybe faster. But instead of a machine gun stacatto of musical tonality, all I hear are "thumps." I cannot get music. The rig was set to CW with a reasonable 500Hz IF filter. Maybe your rig, too.

Solved! My rig's o'scope showed these Morse rounds coming in at less than 10ms per dit, or even per dah. The usual key-down duration on fast stations (which I often SWL) come in at, say, 60ms per dit and up. And the rise/fall times of these odd stations? A couple ms or less, versus the 6-8ms typical of popular transceivers.

So, I just switched modes to SSB and its 3kHz IF passband width (and retuned the VFO, because my "preferred" DSP-based CW listening tone now meant nothing in SSB mode).

Bingo! With rig set to either LSB or USB, then more or less retuning, I can finally receive these guys. Yes, they may even dip down to 25 WPM. Even if modest in SNR, it's a "hi-fi" beat note I can adjust with my main dial to render my preferred 660Hz listening tone. Then I can squeeze down the audio in the DSP to maybe a digital filter bandwidth of 250Hz or less for better SNR and it's beginning to sound pretty good! The key thing was not to squeeze the signal in the CW roofing filter in the first place.

WB CW is not Farnsworth! It retains the intra-character spacing of whatever WPM the op's sending at. Farnsworth allows you to expand the intra-character spacing to slow down the information rate. But this is not that!

So just what are these ops doing with such short key-down's anyway? The bauds have some shaping, so there's fairly little key click, just the inherent wideband-ness of the total signal. But at high WPM, the dits and dahs are just little pyramids of energy. Is this something old or new? Do they fancy it some new mode? Or is it just, I do it because I can?* (And you, or at least I, can't. Yeasu took out the original 1 and 2 ms rise/fall shapes of my rig in the latest firmware - to add an 8 ms option, which an ARRL reviewer recomended for a better sound. Yes, even Yaesu thinks even 2 ms rise/fall shaping is not operationally correct at any speed, up to that 60 WPM every review cites! Let alone a keyer capable of producing tiny little pyramids of signal, hence sound.) You could do it in Yaesu SSB mode using the computer interface, however, I must note!

I have an idea about this "mode." It's a sneaky kind of thing. If you deny a typical transceiver its "CW mode" setting, then it could be (and I'm not sure about all rigs) that you also deny "CW decoding" by the rig's sofware. This happens with my Yaesu. So you end up with a watered-down sort of "stealth CW" that can only be copied by ear (in the rig's SSB mode) or some 3rd party software in a connected device. So these guys might be thinking, "we've got this QSO all to ourselves because the CW hoi palloi, which definitely includes YT, cannot 'read' our signal." Well, that's one theory, folks.

If so however, and maybe in any case, FCC Part 97 says we should not use more than the "necessary bandwidth" to communicate. These WB CW signals are way wider than any other CW you're going to encounter, without any added communication capability. IOW, they are unnecessary in width! In fact, they actually reduce communication capabiity (even for themselves at low SNR, obviously) and certainly help to crowd a band by consuming maybe 10X the width of a typical CW signal. And any sort of stealth is definitely not in the spirit of FCC Part 97. Signals that cannot be decoded by a skilled operator are in a gray area re: encryption, at least practically speaking. In any event, you're glad it's not popular. So is it strictly legal? I don't know. It might be some kind of play on the legitimacy of AM up in the phone band. I'd suggest asking yourself if it denies a freedom to other hams, the basic sort of rule the FCC is promoting (or requiring?). You work it out.

 

* Ah, freedom! (Up to a point.) And a definite digression here, if you will allow. WSPR was IMO just that freedom-because-I-can thing, as there had never before been an overlapped sync code signal in digital ham HF, thus pushing the envelope for binary (yes, WSPR is really a binary signaling schme). And yes, as everyone piles on, I know it's a quaternary FSK symbol. But the sync half channel, as opposed to the other half (data), is not data! It's not even encoded. Alternatively, that sync sequence could be looked at as a DSSS of just one very low rate bit (i.e., that sync channel bit = 1/0 = "I'm right here"/"I'm not right here" at this instantaneous timing point) - and SS is not permissible at HF. WSPR really is not a data-to-4FSK mapping, even if it gets called that, perhaps to squeeze by waveform officialdom! So we get this new, presumably expandable (to as yet uninvented, or un-unveiled, digital modes), Layer 2 construct just for the trying of it. So hey, thanks for having the guts to push the envelope, K1JT.