Morse Code, Redux

[Lauri-CoyoteFrostbite]

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It seems there comes and goes a fascination with Morse Code by modern hams. I think it fascinates us to be able to have our own special way of communicating that others don't understand.... I know, even in this day of computers and personal data devices, quite a few of the younger generation that find it a mesmerizing skill .
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That said, I was going thru files and came across some notes I had from awhile ago. I had been a guest lecturer to Midshipman at the US Naval Academy, talking about one of my favorite subjects; Radio's History.
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The Academy sits in the shadows of the three remaining 600 foot Eiffel towers- all that is left of the once powerful station NSS. A walk about the former site on Greenbury Point, and looking up at those towers from their bases, can't but impress what the former days of Spark, Alternators and long wave must have been like.
For this talk I brought along a lab constructed rotary spark gap transmitter for a demonstration, along with this on my laptop;
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Spark Transmitter
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....one of the best places for the sights, sounds and theory on all things spark gap.
At this site are examples of the Morse audios that I used, as well as one of the most enigmatic recordings - the sounds of voice modulated spark.
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Its nice that Morse is only a passing memory as far as a ham license is concerned. The more it fades into history, the more interested I am.
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Lauri...
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Below is the top section of one of those 600 foot towers... note the platform for the huge Shreve wheel over which the massive cables of the antenna array passed. That fence-like structure about the top is a Faraday shield.
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I have been offered several times, the rare opportunity to climb one of these towers (note the open ladders and lack of any safety cages, platforms etc.) -- getting to experience all the non OSHA era fun of a 1930's steeple jack.
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My answer to such a tempting invitation "You must think I am out of my ever-loving mind !"
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[AK9R]

Cool.

I found them on Google Maps in satellite view: 38.977570, -76.453000.

Surprised that some government bean counter or safety freak hasn't demanded that the towers be demolished.

 

[nanZor]

Great article - thanks for that.

Unfortunately, the audio files are in the licensed proprietary AIFF format, which quickly renders his hard work unlistenable if your hardware doesn't support AIFF.

Something to be careful about - If I were writing an article today, and wanted a bit more longevity from it, I'd choose an open / libre format that all systems can use. The HTML is of course ok, but the audio files, except for the last one in mp3 format can be heard on my gear here without having to use conversion utilities.

Heh, this kind of leads to why morse can be fun - all you need are ears and practice. No battery, no software, no blue screens, no license issues - nothing - but just like riding a bike, it can come back to you after 60 years without needing anything extra.

That's what makes the mode fun. Again, great article however, thanks for sharing.

 

[majoco]

What wouldn't you give for a tri-bander on top of that mast, along with a six-over-six 2m beam of course and a full kilowatt for a bit of extra oomph......

 

[zz0468]

This is both amusing, and fascinating. I am a lover of cw, it's by far my favorite mode. My ears have gotten slow, but in my teens and 20's, I was at about 30 wpm. I have in my collection, a few receivers that would have been used to receive some of those spark gap transmissions. I'd love to know what messages they actually received. Maybe something of significance? There's a reason they were allowed to survive so long.

Lauri, you may find it amusing to know that just this last weekend, there were hams using Morse code on 10 GHz, 24 GHz, 47 GHz and higher. It becomes the mode of choice when signals get weak and atmospheric instability turns that rubidium locked super clean super pure cw note into something resembling a spark transmitter.

 

[Lauri-CoyoteFrostbite]

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When I stand at the base of these towers, the overwhelming thought I get is there is such a thing as TOO much antenna. The area beneath them is larger than a good sized house and lot- the cross beams don't even begin until you go up the sides 80 or so feet. These three remaining towers were built in the '30's, and are of that era's construction techniques that built things to last forever. Except for getting painted and the aircraft hazard lights needing changing every so often, I was informed they are virtually maintence free.
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The other sister towers were demolish'd years ago- but these remain on a national historic landmark list- Mariners and air craft pilots have used them as landmarks for generations--- the land belongs to the Navy, but the towers to Anne Arundel County..... strange relationship- but the county uses and leases one of them to tele-comm companies and other users, including the Coast Guard. I am surprised a ham group hasn't placed a repeater on one - but looking at the logistics of climbing such behemoths gives me butterflies in my stomach. They tell me the view of the Chesapeake Bay from up there is awesome-- I'll take their word
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Back in February 2017 I started this thread about these antennas-- a few more pictures there
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https://forums.radioreference.com/c.../347394-tower-mystery-can-anyone-help-me.html
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The distortion you noted ZZ, on those microwave bands also reminds me of the spark gap quality of signals that aurora does to things. I can recall instances when only CW was usable on 6 metre's- anything else was so ragged as to be unintelligble-- but sounding to me, one whose much too young to know what spark sounds like- sounding just like what I thought spark should sound like.
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Lauri
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[krokus]

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I have been offered several times, the rare opportunity to climb one of these towers (note the open ladders and lack of any safety cages, platforms etc.) -- getting to experience all the non OSHA era fun of a 1930's steeple jack.
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My answer to such a tempting invitation "You must think I am out of my ever-loving mind !"
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I would think the Navy installed a climber safety rail, at some point.

The view would be spectacular, based on what I saw from the top a VLF tower.

Sent using Tapatalk

 

[simpilo]

Spark Gap Transmitter....zap zap zap was actually

-.-. --.- / -.-. --.- / -.-. --.-

 

[Lauri-CoyoteFrostbite]

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One thing, as a student of spark gap that surprises me is the quality of the signals. As its state of the art improved, the signals got better and better. By the 1920's there was a rivalry between it and CW; spark, enduring in some form until the late 1930's for the long wave maritime services.
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My little demonstration rotary gap transmitter is a good example of the state-of-the-art machines at the end of Spark's era. On a modern receiver it sounds terrible, not a whole lot different than an unsuppresed light dimmer switch.
But on a broad crystal receiver- like the types used during this time, the code has a surprisingly sweet sound. Adjusting the rotary speed, the spark gap, the type of gap (rounded electrodes sound more 'musical',) the sparks per second..... all effect the tonal quality.
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This is a lost art form- and those Middies found it fascinating (or they were being very polite ... )
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I have mentioned my great aunt, the Marconi operator in these forums before. She was said to be phenomenal at Morse, able to copy code with one ear to her radio, while the other was to tuned a room full of conversations-- and she could remain fully engaged in both.
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This apparently was a skill these operators developed, maybe were born with; - being able to pick out a certain signal from a mixed batch of many others. Their receiver were broad 'as barn doors'- and they heard everything near their frequency-
There was a unique quality to each spark signal, and it was the identity to each transmitter, so much so that the experienced operator could identify each by their sound, then lock their brain onto it to do the filtering.
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If you are like me, and listen to what "good" spark sounds like, you might think-- like me--
"Hey, I'd like to try that over the air" **
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Lauri
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** but don't !

 

[K7MH]

** but don't !

Why not? It would be a really good way to get to know your neighbors!!

 

[SteveSimpkin]

I would think the Navy installed a climber safety rail, at some point.
The view would be spectacular, based on what I saw from the top a VLF tower.

They did have an elevator inside the main tower which stopped operating in 1995 and has never been repaired (the tower was taken down in 1999).

More information about NSS Annapolis (and a great video) at:
Jim Hawkins' NSS Naval Radio Transmitting Facilities Tour Page

See also:
Naval Radio Transmitting Facility NRTF Annapolis - NSS

 

[Hans13]

Those pictures show a thing of great beauty and engineering. Thanks for the links!

 

[FeedForward]

As cool as all the early equipment is to contemplate, one main point is usually missed in CW discussions. CW or Morse communication was the primary means of communication from the time of its birth up until the invention and widespread use of the telephone. While many enjoy learning and using CW, they still regard it as a quaint footnote to communication science. It is hardly that. It was only recently that we all learned the code before going to the local FCC office to take written and code tests. None of this multiple choice stuff, either.

And beyond the enjoyment of learning and using CW, the very practical aspect is that a CW signal takes up a minimum slice of bandwidth and is readable through fairly ugly static and fading conditions. In a pinch, a workable CW transmitter can be put together with a minimum of parts - the early CW transmitters usually employed a single tube as an oscillator and an amplifier. Not spectacular, but it worked! But here I am equating ham radio with expertise in emergency communications - a relationship that has been severed for some time. My guess is that in a real emergency, cell phones and the internet will be the first to go. Opinionated? Yup.

What is needed is encouragement for learning and using Morse before it is completely forgotten. In that spirit I encourage younger hams to toss out the microphones and develop a useful skill. Unless of course you like listening to the endless blabbering on 20 meter SSB.

-FeedForward

 

[Lauri-CoyoteFrostbite]

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I love the late Victorian, non-electronic telecommunications techniques. And although the operational technologies have changed, their core science and simple principles have not. Most histories of this period fail to adequately tell of those simple early methods and the huge machines their developers had to utilize.
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In the list of these electro-mechnical 'devices' is one I have only read about- if there is still a working one in existence I haven't learned of it... but would love to see and hear one in action: the Poulsen Arc Converter.
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Unlike regular spark gap transmitters that produced signals as broad in frequency as a lightning bolt- the Poulsen Arc Converter's signals were only 100KHz, or so, wide. They approached a pure note CW signal, and at power levels that could exceed 1,000,000 Watts. The transmitters were behemoth arc devices, utilizing a fix spark discharging in a hydrogen environment (hydrogen increases the frequency--- physics, Guys.... ) The limitations were the signal could not be key'd on and off as in traditional Morse; rather, it had to be shifted in frequency, with the receiver tuning in only the wanted, or "forward" bursts. The "back wave," as it was called, was an image of the transmission; something bound to confuse anyone who heard it. This frequency shift was done by switching in and out of the antenna's resonant circuit, an inductance keyed by the operator. The signal could also be simply ground'd out by big relays for spacing between characters bits.
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However, since The Arc Converter could produce a pure CW signal, it was a natural for voice. Some of the very first transmissions of speech were by modulating its direct wave connected to the antenna thru a carbon element microphone.
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Talk about a Hot Mic !!
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..... as the power levels increased they actually used water cooled elements (I can just imagine the trepidation of approaching one of THOSE microphones to sing a song, or something, while a 25KW hydrogen 'TIG welder' I would be sitting next to was arc'ing away.)
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I bring all this up for in a few day it will be Reginald Fessenden's birthday-October 6th. He was the father of telephony, yet history has forgotten him. It is worth a search and discovery of the man behind the first microphones.
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Lauri
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A Poulsen Arc Converter, below-- the size and scale of this picture doesn't do this monster credit....
Such a Poulsen transmitter was used at Naval radio station NSS during WW1.
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[majoco]

(hydrogen increases the frequency--- physics, Guys.... )

...just like huffing helium makes you talk funny....

 

[needairtime]

Speaking of CW oscillators, was there ever a time when spark gap transmitters were mechanically "modulated" ... using a motor that caused sparks to fly at 400Hz or some other frequency to more easily distinguish it from random noise? Of course when vacuum tubes were available to make oscillators, they were much preferred as they're ...quieter!

I was wondering about an audio clip used by the local amateur radio club with some CW. It may well just be an artsy add-on ...

 

[Lauri-CoyoteFrostbite]

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There were quite a few techniques used to 'modulate' a spark gap signal. All of them were quite crude, but surprisingly they did work-- to a point. Their signals were very broad, as seen from the illustration below- but so were the receivers of the era... we are talking really wide band, very low fidelity AM. They used carbon element microphones- never great, even today with modern transmitters.
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The transmitters of this period that utilized spark to generate RF were as varied as the builder's engineering mind could conceive. The speed of a rotary disc, the number of sparks per second, the spark distance, the purity of the supply voltage-- even the shape of the spark electrodes-- all influenced the tonal quality of a Morse signal.
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This is why a good Morse operator, swamped by signals coming over their very broad receivers, could pick out the one they wanted much like how we can understand a certain person's voice above the din in a noisy bar or at a party. Each transmitter had its own 'signature.'
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Returning to voice modulated spark, from my notes--- here is one of the more unusual examples of that creative engineering mindset of the early 1900's. Its hard to imagine mechanical devices as high power'd radio transmitters (try thinking of your vacuum cleaner as an Icom, ) but these things were cutting edge for the time, and real Flame Throwers (pun intended-- )
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" The Morretti's 'hydrothermic' discharger, was used for a radio telephony circuit between Rome and Tripoli (Italy) ca. 1910. It consisted of a pair of copper discs set horizontally, one above the other. The lower disc had a tiny hole drilled through it, and through this hole, a mild acid was pumped. This form'd a thin stream that struck the upper copper disc.
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"An electric current immediately vaporized this acidic jet, interrupting the circuit which was then reestablished, only to be interrupted again-- thus creating rapid current pulses. The operation was automatic, requiring no moving parts.
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"Each pulse would excite the secondary circuit at a submultiple of its resonant frequency. In this way, oscillations persisting in the secondary circuit were continually reinforced to produce a slightly undulating continuous waves. The Morrietti transmitter was power'd by a high voltage DC generator thru a variable resistor. This resistor synchroniz'd the discharges, bring them in phase with oscillations in the antenna circuit. A carbon element microphone was placed in line with the ground connection of the antenna; becoming the quinessential definition of 'superimposing an audio frequency signal on an RF carrier-- ie: classical Amplitude Modulation.'
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................ And, as a lover of Steam Punk, these are quintessential Jules Verne--- like something out of 'Twenty Thousand Leagues Under the Sea"
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Lauri
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[Lauri-CoyoteFrostbite]

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This Saturday marks the 132th birthday of one of radio's forgotten hero's, Reginald Aubrey Fessenden (6 Oct 1886- 22 July 1932) a Canadian scientist and radio pioneer.
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While Marconi is credited with sending the first trans-oceanic radio signal across the Atlantic (there is some controversy about whether it as his signal or static received... but that's another story ) ----- its to Fessenden that goes the first true trans Atlantic radio two exchange.
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During his life time Fessenden was awarded hundred of patents, spanning many scientific endeavours.
But of them all, his most charming --to me anyway, -- was the use of a modulated spark to send the first-ever telephonic broadcast.
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He made history with this first radio broadcast to the world on Christmas Eve 1906. In what he called his "Christmas concert," Fessenden broadcast'd to the crews of the United Fruit Company ships from his station at Brant Rock, Massachusettsout. From this location his transmitter could easily cover the eastern Atlantic well down into the Caribbean. This was 1906 ! ... in the heart of the Spark era, and yet he was about to use AM telephony.
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The broadcast began that Christmas eve with a general Morse call to all the ship stations- Then to the astonishment of all now listening, Fessenden switched over to 'phone and gave a short speech about what they were to hear. The Brant station then began the program by playing, on an Edsion victrola into a carbon microphone, a record of a singer preforming Handel's "Largo." ***
After the recording was played, one of the station assistants was asked to say a few words. In a panic; the first ever record'd instance of radio 'mic fright,' he was unable to say a thing
Fessenden quickly picked up his violin and played 'O Holy Night,' followed by his wife and his secretary who tried to read parts of the Bible, but like station's assistant- succumb'd to stage fright as well.
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That first evening's broadcast ended with Fessenden's return to the mic wishing everyone a "Merry Christmas."
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History has passed you by, Reginald- but some of us won't forget your genius.
A Happy 132th.....
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Lauri
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*** https://www.youtube.com/watch?v=uMlxM69ZJFA
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[Lauri-CoyoteFrostbite]

Reginald Aubrey Fessenden
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( 6 October 1866, Milton,Quebec Canada— 22 July 1932, Hamilton, Bermuda),
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He was a Canadian radio pioneer, who on Christmas Eve in 1906 broadcast the first program of music and voice **ever** transmitted over a long distance.

 

[Lauri-CoyoteFrostbite]

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These guys were truly the first 'hams'----
...........but least I start to get too wrapped up (ie: ' boring') with this step-back into radio's history-- I am going to "SK"
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....73's.....Lauri