Telegraph Keys


Designed and built by W. R. Smith (1946)

While a student at the University of Tennessee 57 years ago, one of my classes had to do with designing and building something and writing a paper regarding it. At that time, electronic keyers for making automatic dots and dashes used for sending Morse code were beginning to be popular. Thus, I decided to build a paddle with which to key one of these for my ham station located in the 17-foot trailer of our UT trailer village. The paddle shown is the result of my effort.

The paddle is composed of two levers hinged at a common arbor. However, it is unique in the manner in which the two of them are maintained centered without making contact to either the dot or dash post. As can be seen, there is a screw through the nearest lever that passes through a larger clearance hole in the far lever and ends up with a spring and a nut. This holds the two levers together. At the far side of these levers is a spring applying a force to rotate them clockwise. However, in the nearest lever, there is a hole and through this hole is passed the end of a screw that centers the two levers in the neutral position between the dot and dash contacts without touching either. This is the secret of the paddle’s design. As the round knob is pressed to the left, the far lever remains stopped against the end of this screw but the right lever moves clockwise and makes the dash contact. However, if the paddle is pressed to the right, both levers rotate counterclockwise at their hinge arbor and the dot contact is made. As will be seen later, this design trick allowed me to design and build vertical speed keys shorter than any ever produced before.

No information for the making of this paddle is available. It is shown only for its interest value.

Designed and built by W. R. Smith in 2006

One day, Tom Perera showed an e-mail picture of an Ultimate 73 key made by the Los Angeles Transmitter Company many years ago. According to his picture of the key by a ruler, it measured 2-1/2” long. I thought it would be fun to see if I could build a working speed key smaller than that. So I set about the task.

I always strive to avoid copying the work of others. However, any short, right angle speed key that has the pendulum vibrating on a mainspring forces the paddle to be at the left and end of the base. Thus, I had to place it there. The resulting key is shown at left. It has silver contacts, all of the adjustments found on a normal speed key and functions well on the ham bands. The speed range is from about 15 to 35 WPM.

The binding posts for attaching a cable for keying the transmitter are the two posts in the upper right hand corner. The key has three rubber feet and all metal parts are nickel plated. To save space, I designed the posts so they grip the screws to retain their setting and avoid the need for thumbnuts. The mainspring is held in place by 0 – 80 pan head screws and nuts.

The picture of the key beside a ruler shows that I have managed to beat the size of the Ultimate 73 key length of 2-1/2” by a considerable amount.

The two pictures shown are of the key as first made. However, I soon discovered that it was very difficult to hold it still without interfering with the function of some of the parts while sending. There is almost no place to grasp it. To solve the problem, I machined an ornate post and a finger pad, plated them and installed them as shown in the next picture. In use, one places a finger on the pad and presses down to lock the little key to the table top. Reflections in the highly polished, nickel plated surfaces make it difficult to see some of the parts. Note the signet paddle with the “S” for Smith.

Mini Key before fingerpad

The picture at right was made before the finger pad was installed. I enjoyed making the key very much and it has become an interesting conversation piece.

Mini Key after fingerpad

I managed to find a finger ring box in which it would just fit. This makes it easy to carry in the pocket. I also quite often give viewers a set of 4” x 6” photographs of the key so they can prove to others that they are not fibbing about what they have seen. As might be expected, there has been considerable interest in the key among hams. However, I have been quite surprised at the interest shown by the general public. Here is the little key in its ring case.

Designed and built by W. R. Smith in 2006

Having just completed the Minikey, I decided to build a small straight hand key. I had seen a number of small ones from the past and realized that to be of any interest, the key would need to be quite small by comparison. I made a base that had a length approximately ½ the diameter of a penny and set about making the remainder of the key to fit that base. It is shown on a penny in the figure at left. As you can see, the base needs to be pushed back to have its end over the edge of the penny. It would then look to be ½ penny in length.

I then began work on the lever portion. A pattern was roughed out and soldered to a piece of steel. Metal was then removed to the edge of the pattern. The pattern was finally removed and the remainder of the work was done on the lever. A spring and a silver contact were added to the base and it, along with two binding posts, was mounted on a black plastic base. A silver contact was added to the lever and a knob was made and installed.


Rope knurled screws and rope knurled thumbnuts were made for locations where various adjustments had to be made. The little key was assembled and adjusted for a good feel. It was then put on the air and given a shake-down run to be sure it functioned properly. It performed well and a number of e-mail pictures of it were sent to friends.

Again, I went to my favorite jewelry store and was able to locate a very small ring case into which to carry it. Like the Minikey, this allows it to be carried in the pocket. I usually offer it with a large magnifying glass so the viewer can see the details of the key.

Much interest has been shown by the ham fraternity, and an amazing amount of interest has been shown by ordinary people who know little of nothing about CW and telegraph keys. Even more often than with the Minikey, I offer photographs of this key so the viewers will not be held in question when they mention what they have seen.

Designed and built by W. R. Smith, W4PAL, in 2006

Since I first owned an Australian right angle speed key, while serving as a radio operator on C-47s in the Pacific during WW II, I have always been interested in them. Having just completed making my fifth unusual speed key, I thought it time to try my hand at a right angle version but using rare earth magnets to make it unusual. After considerable puzzling, I finally came up with a design that I liked and started work on the key. Here is the result of my effort.

Like all of my keys, it has a signet paddle with an “S” for Smith. The pendulum is composed of a square, thin wall tube brazed to a cylindrical weight rod. Because there is no mainspring in the pendulum it can’t bend. Thus, the damper had to be hinged so it could be swung out of the way for weight changes. The dashes are made with fixed silver contacts on the dash paddle and dash post; however, the dots are made by a rare earth magnet passing over a reed switch contained in a small brass tube.

Since the pendulum is rigid, the key has no mainspring. Thus, the vibrations are created by rare earth magnets.
There is one on each side of the pendulum. Facing each of these is a magnet in the head of a thumbscrew. All magnets are oriented to repel each other. A spring pressing against the end of the dot paddle rotates the pendulum clockwise against the force of the magnet pair on that side of the pendulum. When the dot lever is pressed, an arm that has been holding the pendulum against the opposing field of the magnet is moved out of the way. This frees the pendulum. It is forced away from the magnet it has been nearest and rotates counterclockwise into the field of the other magnet. This repels it and sends it back toward the first magnet. In this manner, the pendulum is set into vibration. It continues to vibrate until the dot paddle is released: the bias spring forces the pendulum clockwise toward the first magnet and the damper. The key has a range of from 15 to about 40 WPM and has functioned well in bench tests and on the ham bands. I built it to add to my telegraph key collection and am very pleased with it.

Designed and built by W. R. Smith, W4PAL, in 2006

Having completed the designs and building of the Monovert, Duovert and Magnevert vertical speed keys, I decided to build a key that would be identical to the Monovert but would make the dots magnetically instead of with the conventional dot spring and a dot contact post. Thus, I set to work on it. Here is the result of my effort.

On the weight rod, there is a collet and on the bottom of it is mounted a rare earth magnet. Directly beneath the magnet is a brass tube containing a small reed switch. As the pendulum vibrates, the magnet passing over the reed switch closes it and makes the dots.

The key is the same height as the Monovert and all other mechanisms are the same except for the dot making portion. However, this has resulted in a rather unexpected result. Because of the removal of friction and other mechanical losses associated with the conventional dot spring system, this key has repeatedly shown an ability to make over 100 consecutive dots before giving up. Of course, that many dots are never needed but it is interesting to have a key capable of producing them.

The key has a signet paddle with an “S” for Smith. It is heavy enough that it does not need to be held down while sending. All of the parts are made of brass and nickel plated except for the steel arbor, the bearing screws and terminal post screws. Levers rotate counterclockwise at their hinge arbor and the dot contact is made. As will be seen later, this design trick allowed me to design and build vertical speed keys shorter than any ever produced before.

No information for the making of this paddle is available. It is shown only for its interest value.

While making the key, I did color photographs of each step of the fabrication and wrote a description of what was being done. These were sent daily to my CW friend, Shelby (Coach) Rye, AD4WQ in Dixon, TN. When completed, the second key was presented to him as a gift. He has used it on the ham bands for over a year now and considers it the most favorite speed key among his collection of keys. I am pleased to have been able to do this because Coach was the one who encouraged me to start building speed keys again after a silence of about 70 years.

To adjust the dot portion of the key, the pendulum needs to be moved to the dot making position and barely vibrating. While in this condition, loosen the thumbscrew securing the tube containing the reed switch and slide it until the key is making good dots. Lock the thumbscrew.

The key has a speed range of about 15 to 40 WPM. However quite a few people have been astounded to hear a mechanical speed key make an unheard of number of dots. Aside from that, it is a very smooth operating speed key and a pleasure to use.

Like all of my vertical speed keys, it owes its short stature to my design trick of stopping the dot bar with a screw through a hole in the dash paddle. This allows the dash paddle to be rotated above the arbor instead of below it, as is the position in most speed keys. This was discussed in the description of the paddle for triggering electronic keyers that I designed over 60 years ago.

Here is a back view of the speed key. I puzzled for a very long time as to what the black area on the picture represented. Here is the answer. The vertical portion of the key is set forward of the back surface of the base on two nickel plated cylinders. A portion of each of these is seen. Then, there is a reflection of a portion of the main frame (arch) shown as two brass squares, finally, there is the reflection that contains a portion of the red contact strip. Very puzzling!

Designed and built by W. R. Smith in 2005

At the age of ten, I built a speed key for my ham friend from information in a magazine article. It was quite simple, used a spring from my mother’s discarded corset and was built on a wooden board. At the age of twelve, I built one for myself–a modern type speed key and made of metal. Almost 60 years ago, while attending the University of Tennessee, I built the electronic keyer paddle shown in this site. Thus I have a longstanding interest in telegraph keys.

After returning to ham radio following a sixteen year silence, I again became interested in telegraph speed keys and used my clockmaking skills to restore several for my friends and for my own collection. I then decided to build another key but I wanted it to be very unusual.

Because it had been about eighty years since the last vertical speed key was produced, I decided to do a vertical one but unlike any that had ever been built before. By using the design trick that was used when making the keyer paddle at UT, I was able to fold the paddle and knob of the new design above the point of rotation and make one that stood shorter than any key using a conventional pendulum assembly.

The sketch at left shows the workings of the new key. Its base is of 3/16” nickel plated brass and its foot is formed from a 1” thick sheet of brass and is also nickel plated. As can be seen, the dash bar is hinged to the dot bar at the arbor, and the arbor is supported by bearings in the bridge and the base. The dot and dash bars are held together with a spring and a thumbnut. A second spring against the dot bar rotates the total pendulum assembly counterclockwise against the dot bar position screw. The unique design allows the position screw to pass through a hole in the dash bar to reach the dot bar.

The pendulum assembly is shown in the rest position. As the dash knob is moved to the left, the dash bar rotates counterclockwise at its hinge and contact is made when it strikes the dash contact. Code dashes are thus made individually by hand.

When the dot paddle is pressed to the right, the entire pendulum assembly rotates at its arbor and the dot bar finally strikes the dot bar stop screw. Motion of the weight on the pendulum rod bends the mainspring and causes the pendulum to go into vibration. The contact on the end of the “U” shaped dot spring makes contact with the dot contact and is capable of making about fifteen dots. However, never more than five dots are ever required in code.

The key stands seven inches tall, weighs 3-1/2 pounds, has a speed range of 15 to 40 words per minute and has performed flawlessly during several months of one-the-air test.

This key and my Duovert key are described in my book, How to Restore Telegraph Keys, listed in this Web site.

The world’s first fully automatic mechanical speed key
Designed and built by BY W. R. Smith in 2006

My design of the Monovert key created so much interest in the CW world that I decided to build another key. This time it would be something that had never been seen in the telegraph world—a mechanical, vertical, fully automatic speed key.

In the past, there had been several automatic, mechanical keys made but none were vertical and all were extremely complex with multiple arbors and difficult speed adjustments. I envisioned one with only a single arbor and simplicity of speed adjustment.

A sketch was made and work started on the key. The dot portion worked very well but the automatic dash portion with a “U” type dash spring did not produce an adequate number of dashes and the dash to space ratio could not be made correct. The “U” was abandoned and a reed switch and a rare earth magnet were incorporated instead. This solved the dash problem and the key would then make 50 dashes before the stored energy was dissipated.

The sketch below shows details of the mechanism. The key is composed of two pendulum type vibrators, one for the dots and one for the dashes. The two pendulums are hinged together and have a common arbor that is supported by bearing screws in the bridge and the base plate. The dot pendulum is quite conventional and has the standard “U” spring for making contact for the dots.

The dash pendulum is also quite conventional, except that instead of the “U” spring for making contact for the dashes, it uses a magnet to trigger a reedswitch.

Directly beneath the collet on the dash weight rod is mounted a round, rare earth magnet. In a fan-tail holder is a brass tube in which is mounted a reed switch. This arrangement avoids much of the energy losses in the pendulum and allows it to make far more dashes than if a “U” spring had been used. Also, by adjustment of the fan-tail reed switch mount, the dash to space length ratio can be brought to proper value.

To change the speed, the weight on the dot pendulum is moved to a location that produces the desired dot frequency. The dash weight is then moved to a position that produces dashes that are of correct length relative to the chosen dots.

There is a separator screw that allows positioning of each weight rod against its leather pad in the damper. My design trick of the dot bar stop screw passing through the dash bar allows the paddle and knob to be folded above the arbor and shorten the height of the key. Its speed range is about 15 to 35 WPM and it has performed well in on-the-air tests. This key and my Monovert key are described in my book, How to Restore Telegraph Keys, listed in this Web site.

Designed and built by W. R. Smith in 2006

After having built the Monovert and Duovert speed keys, I became interested in another approach to speed key design—the use of rare earth magnets to make the pendulum oscillate. The idea was simple but it was months before I was convinced that I had found a satisfactory way to start and stop the pendulum motion.

The design details are sketched below. Unlike a conventional speed key, the pendulum has no mainspring. To lessen its mass, its square portion is made of thin wall tubing. One end terminates in a weight rod and the other end in ball bearings.

The dash bar and dot bar are hinged and have a common arbor at the lowest portion of the key. To shorten the key, the dot bar stop screw is allowed to reach it through a hole in the dash bar. When the dash knob is pressed, the dash bar rotates CCW on its hinge and dashes can be made. When the dot paddle is pressed, both dash and dot bars rotate CW on a common arbor. A dot spring pushes the dash and dot bars CCW. At the end of the dot bar is a “U” shaped yoke that goes down and under the pendulum and rises on the far side. This U presses on and rotates the pendulum CCW against its stop.

Bonded on each side of the pendulum is a rare earth magnet. Opposite each of these is a magnet in the head of a thumbscrew mounted in a post. These magnets are all oriented to repel each other. When the dot paddle is pressed to the right, the U yoke, that has held the pendulum against its stop, releases it. Since it has been held away from its neutral position and against an opposing magnetic force, it rotates rapidly CW. However, the magnets on that side stop it and it rebounds toward the force of the original magnet pair. In this manner, it oscillates without the need of a mainspring.

A magnet is mounted on the bottom of the pendulum. Beneath this in a brass tube is a reed switch. As the pendulum oscillates, the magnet passing over the switch triggers it and makes dots—about fifty of them. When the paddle is released, the U of the dash bar returns the pendulum against its stop. The damper can be swung away to allow weight replacement.

The key can also be configured for use as a paddle for keying an electronic keyer. To do this, the stop in the upper right hand corner is released, moved over, and locked against the weight rod to restrain the pendulum. The post, which has previously been used to stop the U yoke of the dot bar, now serves as a dot contact. When the dot paddle is pressed the contact on the U yoke makes with the contact on the dot bar stop screw and causes the electronic keyer to make dots. When the dash knob is pressed, contact is made to cause the electronic keyer to make dashes. The key has operated well in use and has a speed range of about 15 to 35 WPM. Construction techniques for it are given in my book, How to Restore Telegraph Keys, listed in this Web site.

Restored by W. R. Smith

After becoming interested in speed keys a couple of years ago, I began restoring some for friends and collecting a few of my own. Most of those shown above in my collection have been completely restored from true “basket” cases to those only needing cleaning and minimal repair.

Almost all of the keys are of a collectable variety and several of them are quite rare. The three vertical keys at the back of the picture are keys that I have designed and built during the past couple of years. They are described here in the Web site and details of their construction are given in my book, How to Restore Telegraph Keys.

I have a double lever Vibroplex, not shown, that I am presently restoring. It is a right handed key that someone had inverted the base and put all of the hardware on the opposite side in order to make it a left handed key. I will re-japan the base, pin stripe it and upgrade all of the hardware.

Telegraph Gallery