SPARK GAP TRANSMITTERS



HOME BUILT SPARK GAP TRANSMITTER. SENDS MORSE CODE THRU AIR WITHOUT WIRES

the Wanderling


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"Each team member and their equipment was sheep dipped and all teams embedded with specially trained communication personnel, each heavily blanketed with security clearances, versed in Morse code and the non-conventional expertise to build from scratch and use, if necessary, easily disposable spark-gap transmitters and QRP transmitters, along with foxhole radios and crystal set receivers, of which all members were trained to travel light, eat indigenous foods, and leave no tracks."

SHEEP DIPPED: Footnote [2]


It had been a long time since I had built a spark gap transmitter. The first time I was a young boy living on a ranch in the high desert of the Mojave owned by my stepmother. I had been sending and receiving Morse code on and off a good portion of my growing up childhood life using wires, stringing the devices further and further apart to continue to expand the distance between devices and since the distances weren't great, wires were the simplest most expedient transmission method of doing so.

One day my dad bought a brand new, or at least not used, World War II U.S. Army surplus jeep right off the docks in San Francisco for $225.00 cash. He drove it to the ranch and more or less just left it. About that same time I came across a photograph of a war time jeep that had a battery operated radio that could both send and receive with no wires for transmission. Well, we had the jeep, so I figured if I could come up with some sort of transmitting device that ran on batteries, and/or better yet, the jeep battery, I could send Morse code from across the farthest reaches of the ranch from the back of the jeep just like in the photograph.



MY DAD BOUGHT A WWII SURPLUS JEEP OFF THE DOCKS FOR $225 BUCKS.
SAME AS THE SARGE IN THE PHOTO I WANTED TO SEND MORSE CODE TOO

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The thing is, at the time, even though my dad was able to buy surplus jeeps, surplus radios were a little beyond my boyhood pocketbook. Even though my stepmother saw to it I had almost anything and everything I ever wanted, she didn't live on the ranch per se' and I only saw her intermittently. So, in between visits I began to research if there was some practical way I could build or make what I needed either inexpensively or with stuff I already had laying around. It wasn't long until I came across what is known as a spark gap transmitter. From my research, along with a little adult supervision, I was eventually able to build and operate a successful spark gap transmitting device, easily sending Morse code clear across the ranch to my brothers with a receiver in the barn.

The adult supervision turned out to be a sort of shade tree mechanic type guy that ran a scroungy looking one man auto repair shop on a side street a couple of blocks off the main street. Always in coveralls and always with a whiskey flask in one of his pockets, he told me he had been a mechanic and driver for General George S. Patton's Red Ball Express during the war and I was sure he could change a water pump using only a hammer.[1]

Without having ever seen him or talked to him I stopped by his shop one day on the way home from school to see if he had an old ignition coil laying around that was still good that I could have. When I told him I was going to use it to build a spark gap transmitter he said he had built one as a kid in high school years before but he didn't think kids did that sort of thing anymore. He told me to come back in a couple of days and he would have a coil for me. When I came back he handed me a brand new coil in a box at no charge, but what he really needed the couple of days for was to look around to find the spark gap transmitter he had built in high school. He eventually found it stashed away in a box at his mother's place. He said if I got a nice clean mounting board I could come by his shop and use his workbench and tools, and using his transmitter as a blueprint, build one just like it. And that's what I did.

I had gone down to the shop to work on the transmitter early one Saturday when about mid morning a brand new shiny Cadillac Fleetwood drove up outside the garage bay doors. The driver got out and came around to open the other side door and out stepped my Stepmother. The mechanic was there in a flash asking what he could do to help and she told him I was her son. By then I was running toward her to give her a big hug with her asking me just what I was doing in such a place. The mechanic was visibly shaken seeing a person of such stature in his shop, easily seeing even the jewelry she had on was probably worth more than he earned in a year, with the suit her driver wore probably costing as much as if not more than he made in a month. She had only just come up to the high desert from Los Angeles and yet to put on her "ranch" clothes when she was told I was in town, so she immediately came looking for me, decidedly curious as to what kind of trouble I was getting into now.

I took her hand and led her to the workbench showing her what I had been doing, she being careful all along the way not to touch anything or be touched by anything. Having no clue as to what I was babbling about, spark gap transmitters and all, she noticed I had been drinking a coke from a bottle and asked if there was any more. The mechanic said there was a coke box out front but before he could make a move she made a slight head gesture toward the driver and he was back within seconds with an ice cold coke for each of us. Sitting down on the tall workbench stool crossing her beautifully suntanned bare legs, wardrobe matched wedged high heels, and bright red toenails, all the while uncharacteristically sipping coke from a bottle, albeit with her pinkie finger pointing out, she slightly leaned toward my transmitter project on the workbench. Recognizing the battery as the power source I began running my fingers along the wires telling how the device created a spark across the gap sending out radio waves and she immediately grasped the concept saying, "Aren't you the little Da Vinci."

With her comment and sitting there in a greasy old auto repair shop drinking a coke out of a bottle, talking with the mechanic and joking I knew everything was OK. Soon she said we should go and as she was getting up she took a business card from her purse and scribbled her signature or initials on the back and handing it to the mechanic told him if he ever found himself in a situation and felt she could help, to call her. On the way out I turned to wave so long to the mechanic and as I did I could see the driver peeling off a brand new hundred dollar bill and handing it to him saying it was for the cokes.

The next time I had any experience with a spark gap transmitter was many years later in the Army. They sent me to a two week two part hands-on workshop or seminar where, after classroom introduction to theory and application, we built and operated our own spark gap transmitters from stuff that could pretty much be just scrounged around for --- and made in the field without using any commercially available or already made tools. In other words, side cutters, screwdrivers and such weren't allowed, so we had to improvise. At the end of the workshop we were all supposed to end up with a viable operative spark gap transmitter, of which I did. Then as a group we shared what we each had done individually to improvise tools and how, that is, what we did, use, or came up with in lieu of screwdrivers, drills, or wire cutters --- or did we implement shortcuts or discover other options. Telegraph keys weren't provided either, so we had to make those from scratch too. Although ignition coils were acceptable, at the end of the seminar we were taught how to make our own induction coils from scratch, along with their application and use as well as learning about devices other than traditional spark gap transmitters that could accomplish the same purpose.[2] [3]


By now most of you have pretty much figured out a spark gap transmitter is a wireless transmission device that has the ability to produce, propagate, radiate, or send out electromagnetic waves, i.e., radio waves. A rather simple bare bones, even crude or primitive device electronically, it's primary function is to send out the dots and dashes of Morse code over some distance without the need for transmission wires. For the most part, operating a spark gap transmitter, because of a host of national and international laws, is considered illegal because of the disruption their signals cause to regularly controlled radio and TV signal transmission

In the above two schematic drawings both show what is called the need or use of an induction coil. Now days, as far as homemade spark gap transmitters are concerned, except for purists, the induction coil has been replaced by a typical and usually readily available standard automotive ignition coil. After the coil the next main item is the spark gap mechanism, sometimes called an oscillator. The spark gap device is termed an oscillator because when the electric pressure at each standing end of the gap becomes great enough to break down the air between them, the electric wave oscillates or vibrates very much as a string of a musical instrument oscillates when struck and the electricity, attempting to complete its journey jumps the gap creating the spark. The so created spark or disruptive discharge that occurs does not in and of itself create radio waves. It excites resonant radio frequency oscillating electric currents in the conductors of the circuit. The conductors in turn radiate the energy in this oscillating current out as high frequency electromagnetic waves, i.e., radio waves, in every direction to a very great distance.



(source)


An ordinary Morse telegraphic key is connected in series with a battery and induction coil, as shown in the diagram. When the key is pressed the circuit is opened and closed alternately by the interrupter and a miniature flash of lightning breaks through the insulating air-gap between the oscillator tips. The oscillators are usually adjusted so that not more than an eighth of an inch air-gap separates them. The reason the correct distance adjustment is important is because in wireless telegraphy it has been found that a "fat" spark emits waves of greater intensity than a long, attenuated one.

The coil and attending equipment can be mounted on a base, however for convenience, it is probably best for the hand key to be mounted on a separate base.Together they, with the battery, constitutes the wireless transmitter with the exception of an aerial wire leading upward typically suspended in some fashion outside and another wire, leading from the instrument, connected as a ground with the antenna and ground wires then connected to the oscillators--one on either side.



In the above coil schematic the Input Terminal, or power in from the battery side, the heavier bold wire, is on the left, forming what is called the Primary Coil. The high-voltage Output Terminal is in the center created by the outgoing wire of the Secondary Coil. The low-tension Negative Terminal or ground, is on the right.

Although the end results are the same, because of differences between induction coils and ignition coils --- in that each were designed to serve different purposes --- the wiring for a spark gap transmitter using an ignition coil is slightly different than traditional schematics. In an ignition coil the primary is wound over the secondary, which is wound first. Notice in the ignition coil drawing above that the primary and secondary ignition coil are connected at one end just prior to exiting through the Negative Terminal. Ignition coils are manufactured that way because in a car ignition system, both the primary and secondary coils need to be grounded to the car body. Connecting them together inside the coil container itself is a way of making that possible with only one external connection. Induction coils have a slightly different design.

An induction coil, like an ignition coil, has two wound coils inside, the primary and secondary. In an induction coil primary coils are located inside while the secondary coils located in outer side, so the magnetic field of the primary coils will hit the secondary coil. If the number of turns of the secondary coil is less, the output voltage is decreased. If the number of turns of the secondary coil is greater then the output voltage will increase.

In the ignition coil, as mentioned previously, the secondary coil is located inside the primary coil. The induction of the ignition coil does not occur when there is a current that passes through the ignition coil but occurs when the current in the ignition coil is cut off. The primary coil will issue a magnetic field when electrified. This magnetic field will occur in the outer area due to the position of the primary coil in the outside area. When the electric current is cut off, the magnetic field that was previously formed will collapse, moving rapidly towards the inside The instant and simultaneous movement of the magnetic field will induce secondary coils with stronger results. As a result, the secondary voltage will increase hundreds of times from the 12 volt input to upwards of 25,000 volts or more output. In the meantime the iron core job is to enhance the movement of the magnetic field from the primary coil, maximizing the natural movement of the magnetic field described above to be focused more intently into the secondary coil.


WESTERN UNION STANDARD RADIO TELEGRAPH SIGNAL SET


MORSE CODE, HAND KEYS, AND DA VINCI


THE CODE MAKER, THE ZEN MAKER
SHANGRI-LA, SHAMBHALA, GYANGANJ, BUDDHISM AND ZEN

THE SAIGON TEA GIRL


THE DANCER
WIRETAPPING THE VIET CONG



CLICK
HERE FOR
ENLIGHTENMENT

ON THE RAZOR'S
EDGE


E-MAIL
THE WANDERLING

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As to the subject of donations, for those of you who may be interested in doing so as it applies to the gratefulness of my works, I invariably suggest any funds be directed toward THE WOUNDED WARRIOR PROJECT and/or THE AMERICAN RED CROSS.


The opening graphic at the top of the page of a ignition coil spark gap transmitter was graciously provided by long time radio aficionado, educator, and enthusiast John Welsh

















Footnote [1]




Regardless of how unkempt the mechanic may have looked with his greasy coveralls and a day-or-two old unshaven face along with a scroungy fairly cluttered repair shop, when things were slow, which was most of the time, he was working on and restoring a 1946 British sports car called a MG TC --- not a customer's, but his own --- and he was absolutely meticulous in every movement and part in doing so. All of the work that could be done by him he did, but even so, relative to his income, a hard working vet that came back from the war with nothing like millions of others and just trying to make ends meet, it seemed like he spared no expense.

When the mechanic was stationed in England he became enamoured with British sports cars, especially MG TC's, even to the point of buying one and shipping it home. After he got it to the U.S. he discovered it was a little more under-powered than he liked, the engine turning out only 54.5 horsepower. So, in the process of his restoration he decided to install a Ford V8 60 engine in it, a Ford V8 60 being a much smaller and lighter V8 than the standard Ford flathead of the time. However, the hopped up version he was installing, that he hopped up himself, turned out 120 horsepower, more than enough he thought to make the TC as quick as it looked.

Most of the repairs in his shop seemed to lean toward trucks and farm equipment, plus like I've said, his general appearance and the appearance of the shop was a little on the unkempt side. However, the MG and the V8 were both immaculate and beautiful in their own way, plus relatively small and more watch-like compared to the average farm tractor. Up to that time I had never seen an MG or even a sports car that I recalled, his being my first introduction to them, but I must say I liked what I saw. The second car I ever bought, and I was still a teenager at the time, was an MG, my first car being an early 1940's Ford Woody Wagon that I spent hours on restoring and maintaining the wood.



1948 MG TC WITH FORD FLATHEAD V8 60. KREGG HUNSBERGER OWNER
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A couple of blocks from the mechanic's shop was a drive in restaurant called Welch'es Drive In. The drive in was owned by the father of a classmate of mine, Ann Welch, who I had a crush on, although I have to admit it wasn't as two way as I would have liked it to be, not even being sure she knew my name. Anyway, they had a relative, or so it had been said, named George S. Welch, one of the two P-40 pilots that got off the ground during the attack on Pearl Harbor, shooting down four Japanese planes in doing so. At the time we are talking about here he was a test pilot at nearby Edwards Air Force Base. I was always after Ann or her father to introduce me to Welch, but it never came about. The thing is, he drove an MG TC and used to drop by the mechanic's shop on a regular basis to see the progression on the mechanic's restoration. When I heard he did I always hoped he would drop by while I was working on my spark gap transmitter, but he never did.



GEORGE S. WELCH, SEEN WITH HIS 1946 MG TC AND
A BREAKING THE SOUND BARRIER XP-86 SABRE JET

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TAKING OUT THE FIRST MEATBALL
KENNETH TAYLOR, GEORGE WELCH, PEARL HARBOR, AND THE P-40


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THE WANDERLING'S '41 FORD SUPER DELUXE WOOD STATION WAGON----RIGHT OUT OF HIGH SCHOOL, MY FIRST SPORTS CAR, A 1952 MG TD


OF COBRAS, SCARABS, MASERATIS, AND ZEN


CARROLL SHELBLY'S FIRST RACE AND FIRST WIN WAS IN A MG TC. HE FIGURES BIG IN THE ABOVE LINK
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Footnote [2]


HOW TO BUILD YOUR OWN TELEGRAPH KEY


















Footnote [3]



FOXHOLE RADIO USING A RAZOR BLADE AND PENCIL LEAD

As a kid in elementary school and clear into high school I was always making crystal sets, actually having started well before elementary school by building what was called a 'foxhole radio,' a kind of primitive or rudimentary device like a crystal set that just "runs on air," made in such a way that they can receive radio stations, as shown above, simply by using a razor blade and pencil lead with no battery or electricity required.

Never satisfied with the one I just made I was always trying to make bigger and better ones to pull in farther and farther away stations. Because the signals of far away stations were always weak and the sound low I decided I needed the best pair of earphones I could get. So saying, my Uncle took me to the giant Palley's Surplus Store off Alameda Street and Vernon in L. A. to pick out a pair of war surplus earphones with a full set of large foam rubber ear pads. Palley's had everything and we used to go there often with me always returning with a bunch of World War II army surplus stuff --- canteens, pistol belts, parkas, infantry backpacks, army M43 folding shovels, and two of my very favorites, an Army Signal Corps J-38 Handkey, one in its own little case, the other with a leg-band tagged as a KY116/U, both for sending Morse code and an ESM/1 Emergency Signaling Mirror.

Take a look at the beautiful machine work that went into making the KY-116/U, an item, like the formidable four wheel drive jeep, that was made in the time of war for war. Both in their own ways masterpieces each built for a different function but to serve the same purpose --- defeat the enemy. Wartime jeeps and telegraph hand keys like the KY116/U were turned out by the thousands and thrown into extremes as far ranging as the Arctic, the sweltering wind blown desert sands of North Africa and the steaming jungles of the the South Pacific and Southeast Asia, and expected to win the the war with all possibilities of being destroyed any second doing it --- along with their human operators and caregivers. Even so, made for war or not, or to last seconds or forever, there probably isn't a more beautiful piece of machined metal than the KY116/U below. Well there may be one thing: SEE


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It wasn't long before I discovered all the earphones in the world would not solve the problem of bringing in weak or far away stations. My next step was to jump to "electricity." In doing so I bought and built a small build-it-yourself one step above a crystal set kit that ran on electricity called an Air Champ AC-100 One Tube Radio Kit:


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I'M IN LOVE!

MARIA, THE FEMBOT FROM FRITZ LANGS 1927 MOVIE METROPOLIS

IN LOVE? BEWARE OF WHAT YOU WISH FOR
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ROBOT WOMAN