J. K. Bach
Ivy Hill Road
Walden, NY 12586


Glass Arm

...the dreaded CW man's disease


This is the age of the Natterer, SSB, FM via repeater, Teletype, slow scan. And a little bit of Hand Modulation, mostly confined to Novices and old men.

Nearly all the old men use an electronic keyer of some sort, usually a very complex sort. A very few use the mechanical Vibroplex. None use a hand key, so far as I know. Only Novices use them, and in most cases, pretty badly. This is a pity, for the fluent use of a hand key is less a skill than a knack. In any case, the art has long since been lost.

There are any number of books that tell you how to hold and operate a hand key. Every book on learning code does, whether it's the Army Training Manual or those produced by various magazine and book publishers. They tell you everything but how to send, as long as you like without acquiring Telegrapher's Paralysis, or “Glass Arm.” Either they never heard of it, or think it wiser to leave the question alone. While very few of us use keys much, it is nevertheless a very useful and important skill.

The QRPp boys climb mountains with their two pound CW transceivers besides VFO-buffer, FET, four transistors, and an IC, the thing has to have a solid state keyer which is even more complex than the unit it serves. How nice if a small mechanical key—homemade—were mounted on the clip board used for copying. Or even one of those Japanese dollar keys that have been kicking around for the last twenty years. Compared with the “good” solid brass telegraph keys, they never induce a “Glass Arm”—while the “good” ones will.

So, the Japanese ones not only save money, weight, battery power, and bulk, but they also save arms and improve sending, too.

It helps in your FCC examination if you can send properly. Only one in ten, or so, fail because of sending, but even that is too much. The straight keys are mounted on each desk where candidates sit. They are easily adjustable, and are usually left in some weird setting, such as with a half inch contact spacing.

The receiving exam eliminates many of the applicants, so that the examiner has only a few to watch, as he prepares to listen to each one. As each hopeful adjusts the key to his liking, the examiner makes bets with himself about who will fail and who will pass. He gives each applicant a paragraph out of a manual to send.

It is easy to tell if you passed. The examiner does not congratulate you and shake your hand, he listens to your four or five Vs and the first two or three words, and says, “that's enough.” You'd like to finish the paragraph but he won't let you. From the first two or three words he knows that you could send for fifteen minutes without a mistake if allowed. He knows telegraphers he's one himself. If he lets you send two sentences, you may scrape by. Half a paragraph only if he thinks he can find therein some excuse to pass you.

Receiving, of course, is an entirely different matter requiring different skills. It is very definitely harder, as any ham knows.

In sending, there are two schools of thought about the management of elbows: on the table and off the table.

If you embrace both, the key must be mounted on a board with a non-skid surface, so that it may easily be moved as required.

A hand key requires complete control. The hand must be easy and relaxed, but still in full control of everything the key-lever does. Do not depend on the return-spring; its function is to keep the key open when idle.

For your first practice session (of course you have to practice, but not for long) the key return-spring should be removed entirely. Put the spring in a glass jar so it doesn't get lost.

Now, in order to send, you have to “pump” the key-button up and down, holding it between forefinger and thumb. It is just as important to lift up as to press down.

A very good exercise is a long, slow series of dots. It is even better to time this by saying aloud “Dot, uh, dot, uh, dot, uh,” making the mark (dot) and space (uh) as nearly the same length as you can. When you get into the rhythm of it, it's easy. But don't speed up.

Silly as it sounds, this exercise will do a lot for you. Do it only until you begin to get tired of it, then quit, put the spring back in and send normally for a while. Don't push it. Next day, the same. When the dotting gets easy, then you don't need it any more and can forget it.

You will discover something. You won't like the spring as stiff and heavy as you did before. Not really light, but not heavy at all.

One precaution: Don't let the family or friends hear you going “Dot, uh, dot, uh,” because they'll think you're going dotty.

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Only you can tell how much it has helped your sending. It will be less “choppy” and “itchy” than before. And you will develop a sense of timing that helps, not only with hand-sending, but also with many keyers. You won't need any “self-completing” feature, because you will be the boss of the keyer, not its victim. I have seen a keyer shake a man like a dog shakes a rabbit—a nervous phenomenon we'll come back to later. Learn to send even dots. It takes less than half an hour, spread over the week, and you're sending—even on a printer keyboard—will improve. And be easier and more fun.

After dotting, dashing is even easier. Again you time it with words or syllables “Da da dash uh dot uh dot uh dot uh dot ha ha ha da da dash uh da da dash uh da da dash ha ha ha da da dash uh dot uh da da dash uh da da dash.” Boy!—what a way to write it! The da-da-dash is all mark, key down, of course. It times the dash as equal to three dots run together, as it should. The “uh” is the unit space as before.

Now, we need a word space. “Uh uh uh” sounds like admonishing the cat, so I have substituted the friendlier “ha ha ha” as a three-unit space.

Of course, you can substitute French or Japanese or whatever, and in any case you don't have to practice this long. You need the practice only so long as it isn't easy. When it is, you have graduated. Don't make work out of it—do it for fun, and see how fast your sending improves.

I have emphasized slow sending—slow and even, with dots and unit spaces of like weight—because this prevents a jittery, choppy style which is hard to read and murder on the fist. It sounds a little heavy, but your dots never “drop out.” And when you take your exam you will find that the black, cast iron Beast from Hell with the oil cup on top of it (which the examiner won't let you look at) is adjusted to send perfect code—not that stuff on tapes and records, and even on the air.

A very good check is to watch your plate milliammeter—you do have one, don't you?—or, for practice, send into your ohmmeter. Dotting should read exactly half the key-closed value, if you dot at a reasonable speed. In the old days, telegraphers used to adjust their bugs this way, using line current as a guide.

can o' spam

If in spite of everything (and I won't believe this) you still jitter and suffer from nerves when you send, a good stunt is to weight your key. Now you know what the photograph is about! I used a can of meat because metallic lead is poisonous, hard to handle, and more expensive than the choicest cuts of meat. Any pound weight will do. A pint of milk, a pound of meat—anything. And it won't be wasted—fasten it on the key temporarily, and practice a while, letting it slow and steady you down, and then eat whatever it is for lunch. I did, yesterday.

The British have understood heavy keys for a long time, while we laughed at them. We could send twice as fast with our light telegraph keys, while they used a key you gripped with a fist and—it seemed—pumped water with. We laughed, but did you ever see a Limey Sparks with a glass arm?

Again, try to prevent your friends from seeing the weighted key, but if they do, shrug and laugh along with them. Which of you is learning the most, and who is laughing when he could be learning? You're earning your opinions. Let them have their fun.

So far I haven't mentioned the “tapping” technique. There was once a popular radio organization of “A-1” guys called “I Tappa Key.” Do you know who taps keys? Old telegraphers with glass arms and their imitators, that's who.

It seems stilted and pretentious (and inflexible!) to sit down with your feet flat on the floor and send with a hand key, using the edge-grip. This is very much like the Palmer Penmanship Method which we Faithful Old Fellows learned generations ago. And this is no accident. If you write a lot by hand, you either use it, or your hand cramps and you wind up writing an illegible scrawl.

Besides, editors demand typewritten material, and for good reason.

While I write like a doctor, I can send with a hand key as long as I want to—with very few errors. And with a Bug, and with any solid state keyer.

I had a buddy once, who got himself a glass arm. He could not send even one word with his right hand, so he switched over and relearned to telegraph with his left. It was just a matter of time before the left went too, but he got himself promoted and didn't have to telegraph any more. So there is a remedy, but avoidance is the best policy.

And this is easy. The secret is in the key adjustments—you loosen the “trunnions,” or the tightness of the needle-and-cone bearings on each side of the key, until you can shake the key lever from side to side. There must be as much side-play in the lever as there is up-and-down motion between the key contacts. That's all there is to it.

You won't believe this. That's all right; I didn't believe it either, until I proved it through experiment. The dollar key I mentioned earlier has no side adjustment. Either it has cylindrical ears that poke through holes in the U-shaped mounting bracket, or it has conical ears which should be ground into cylinders. Never mind the sloppy feel; your arm is more important than anyone's opinion. You need that slop, whatever key you use.

Probably you have a good solid brass key with side adjustments. Well then, unscrew the side screws and lock them at the point that you can move the lever sideways the same amount that you pump it up and down.

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It will feel “funny,” but send a few minutes—at least a paragraph. If you can keep going, do so.

Now adjust the key up snug. Not to binding, or with noticeable friction; just barely enough to prevent side-motion. Now send, and see how your arm feels. Does it begin to tighten up, and do you begin to make errors?

Loosen the key. You may need a couple of sessions to convince you, if you are on the stubborn side, so there is no need to risk your arm while you decide. But the arm, and how it feels, tells the story. Stubborn or no, I know how that key adjustment will wind up! You will never send with a tight key again.

So much for the practice, now for the theory: Our grandparents used to explain any number of things as being the result of “nerves.” The trouble with one word explanations is that they don't lay it out for you. In this case, though telegraphers and doctors alike knew perfectly well that Telegrapher's Paralysis was a nervous condition, only the more observing saw any connection with a tight key and a glass arm. And even they hadn't the least notion how such connection might work.

The first clue came from the work of H. S. Black, of the Bell Telephone Labs, who invented negative feedback amplifiers in the thirties. To him the invention meant stable telephone repeaters, and high fidelity at less cost. But to physiologists, experimental psychologists, and other researchers into the living body and its operation, it offered an explanation that had been lacking before. When you put your hand out to touch something, how did the hand stop where you wanted it to? Feedback, by various paths, was a concept that fitted all the observed facts. It simplified explanations; it predicted results. The idea that something caused by the original action that opposed and controlled it was new and exciting.

I have two pocket calculators. One has a keyboard that clicks under finger pressure, like a typewriter key. The other keyboard has keys of the conductive plastic foam type. And be it ever so bounceless, I don't like it, because it feels just like stepping in a cow-clap. It is just mushy; the other keyboard lets my fingers know when to stop pressing, with a click that is felt as a vibration. Expecting this, I actually cracked the circuit board on which the mushy keys were mounted, trying to make them react as expected. I had to cement another board onto it to prevent breaking the printed connections.

Also, I worked for a time at a broadcasting station as a transmitter operator. The on-off buttons controlling the circuit breaker for the high voltage were of the industrial type. They were spring-loaded and all that, but had absolutely no follow at all. Everybody hated them—you couldn't tell anything by feel. They gave a disconcerting impression of anticipating you, as if they operated while you were only thinking about pushing them.

Ask any target shooter what a bad trigger pull will do to his scores.

The fact is that most of us are confused and uneasy when something doesn't “feel right.” This applies to telegraph keys, too. The rigidity of the side-adjustment, the absence of side-play, dulls and reduces the feedback that monitors what flows out of our brain, down the arm to the fingers, and into the key. This is my theory. No one else has ever said that this is true, so far as I can find out—and I've tried!—if only because telegrapher's paralysis is as dead as its victims, for the most part. It is one of the rarest of diseases, so far as telegraphing goes, but it has other manifestations, and should, by all means, be understood.

We have to have feedback, lest the nerves rebel through confusion. I have seen a man standing, back arched, face contorted, arm stiff, trying to telegraph by tapping. I didn't laugh. Telegraphing was part of his job, and for him it was torture. Of course, he could send like a streak with a bug. If you check the old ads, you will see that they claimed “ease” and “speed” as selling points. But bugs were and are very expensive—aside from a few a few broker operators, most sales were to telegraphers who had glass arms. They were as helpless without their bugs as a present day grammar school student without his pocket calculator.

Lyall Watson, in his book Super Nature, has some interesting things to say. He tells of experiments in 1946 in which Grey Walter and his colleagues used flashing lights during brain wave tests and their patients went into convulsions. Other workers have had similar results when the rate of flashing coincided with certain brain wave patterns. The most consistent seizures occurred when the brain waves themselves were made to trigger the light, something like a buzzer of multivibrator action. Under this arrangement, half of the patients had spasms. And they had no history of epilepsy! Watson also mentions a bicyclist who blacked out while riding down a lane with trees along its sides. When the sun was low enough, the flickering produced

by riding past the line of trees was enough to cause blackout—not just once but several times. How many mysterious automobile accidents, do you suppose, are caused by something like this?

In 1927 I went to work for AT&T. I knew a little International Morse, not much, and I discovered that Morse was quite a lot different. It was faster, too, once you learned to read spaces between clicks instead of tone pulses.

There was a full telegraph department with a few printer circuits, but mostly hand-operated Morse. In the test room, where I worked, there were at least a dozen “test wires.” These were simple Morse circuits with a sunder mounted high, well above the jack-fields, next to the carvings of “Nekkid Wimmen” which were standard decoration in those days. Now we got plastic strips. Down on the keyshelf in a clutter of switch-keys and cord-circuits and such, dwelt the telegraph keys. The clutter was not conducive to good sending, but we had men who could do it. For one thing, telephony was just something added to their Morse experience. They were operators; that is how they got their jobs. They learned how to operate a Wheatstone Bridge, and gain a repeater, and that was about it. The test wires were used for communication between offices.

In those days, a telephone route between cities was likely to have just one standard 40 wire line. Open wire, not cable. That meant 20 side circuits, ten phantoms, thirty phone circuits in all. The side circuits were all composited (a composite set was a low pass filter) and a telegraph wire—nearly always half-duplex—could be connected to each wire, giving forty telegraph wires, two way. That is where the name “and Telegraph” comes from. These did not carry public messages, by agreement with Western Union they were all either leased wires, or test wires.

You had to be conscious of your own office call; when you heard it, you interrupted the circuit to “break” the distant operator. When you heard the wire close, you said “I” and listened to his first words. Invariably he wanted something simple, and, while he was telling you, you walked away and did the job, listening all the while. Then you came back a few seconds later and said OK. The most convenient system you ever saw; it took a lot of effort and determination for the High Brass to kill it. We liked it. Radio Traffic men ar3e aiming at such operation with their “break-in.”

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I was just a kid then; my co-workers were 30 to 60 years old. The older men got bored when work was light and they weren't kidding me. Then they resorted to horse-play. A favorite gambit was to loosen the trunnions to the critical point so that when the key was touched, the lever would explode out of it like a mousetrap and the spring would be lost. The victim had to try sending with the switch-lever, by which the circuit was kept closed while idle. This is like telegraphing with a knife-switch, and he would swear loudly to the delight of the perpetrators.

As I say, I was young. This did not suit my sense of propriety. Besides, I had noticed that, even when in working condition, the adjustment was very sloppy. So to be helpful I would tighten them to what I thought was the “proper” adjustment. In other words, I was a wise guy, just as the kids are today, and for the same reason: ignorance.

My “adjustment” never lasted long, so one day I took a pair of gas-pliers and tightened all the lock nuts.

And then it really hit the fan. Grown men running up and down and cursing and threatening mayhem and worse for the unspeakable scoundrel who not only messed up all the key adjustments but had the unutterable gall to LOCK them that way! I watched them searching behind the test-board and under the duplex tables and even up on the cable racks for the dastard, whoever he might be, while I was in plain sight and feeling a little exposed. I knew who it was, all right. It was me. I was dimly aware that I was being taught something, and with more tact and good humor than I deserved. Later I, too, put on a show of rage and incipient insanity when as a chief, I had to make a point. You can't do it often, but it works, it works! The difficulty is in keeping your face straight.

I asked one of the older men, who had been patient with me, what it was all about. “Don't you know? Send on a key without side-play and you get a glass arm!”

My informant was one of the few, even in that office at that time, who knew what caused Telegrapher's Paralysis; he knew that it was due to bad key adjustment and “nerves,” and that was as much as anyone knew. In the years since, I have asked questions at every opportunity and so far have not one answer that means anything. I have puzzled over it for those same years, and the work of Norbert Weiner and others gave my first clue. It is entirely possible that I am the only man alive who actually does know; I hope not, and would be delighted to hear from anyone else who does. But I am afraid that, until now, I have been the torch bearer.

This story will undoubtedly be classified under Dewey Decimal System in some library or other, and will still be obscure. However, it will be in print, and not locked up in the heads of dead men. The knowledge, aside from help to key men, might even furnish an important clue to the psychologists and other workers in the field.

Be that as it may, you have no excuse for acquiring a glass arm. You know better.

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(J. K. Bach was likely a pseudonym and probably also an inside joke in Peterborough.)

Originally appeared in 73 Magazine
June, 1976.
Reprinted with permission of Wayne Green, W2NSD, publisher.

Last updated: 20 July 2012

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