Here are some excerpts from my new book, Surviving Technology, which will be coming out before Christmas 2011.

Regenerative Receivers 

“When I retired some twenty years ago, I had been building radios and radio equipment for most of my lifetime. Then, one day I was reading something in QST magazine that caught my imagination. A writer was describing the National SW-3. “It was,” he said, “so sensitive that one could hear a flea walking acrossEurope.” He continued extolling the virtues of the SW-3 and its “velvet smooth regeneration.” I suddenly realized that here I was, a retired radio technician, an old man who had spent most of his life as a Ham, one who had earned his living keeping radio equipment working, and yet I did not know anything about the most basic radio of all—the regenerative radio receiver. I determined to fill my vacuum of knowledge and experience about those quirky little radios very quickly. I feel I have—but in doing so I’ve discovered all over again the excitement and enthusiasm I felt with my first radio-building project. Since retirement, at the time of this writing I’ve built ninety-seven regenerative radio receivers. In my spare time, I built two Superhets, six legal limit linear amplifiers, five 100-watt class transmitters, a number of QRP rigs, several antenna tuners, and numerous other radio projects. One might say my life has been one long love affair with radio; first as a young SWL and would be Ham, later as an active Ham, and then as a radio mechanic and radio operator in the Air Force. After two and a half years at theUniversityofArkansas, I opened a radio repair shop. The shop grew in size as the radio art progressed; evolving into a full-blown audio-visual home entertainment center. Thirty years later I retired, and once again returned to hamming, DX-ing, and ultimately to spending most of my time in the shop, building and experimenting with circuits long considered obsolete. I still operate on 20 CW occasionally, but I prefer spending time at my workbench building projects from long ago—those wonderful sets of the golden age of radio. “

—Summer of 2009



Two Ways of (Ham) Life 

“To help us better understand what is happening in Ham radio let us look in—unobserved—as two Hams living in the same small mid-western city enter their “shack.” Keep in mind that both Hams are from about the same income bracket and both are near middle age. We will refer to them simply as Joe and Jim. 

Let’s visit Joe first:

Joe’s shack is located in the corner of his bedroom. A small uncluttered desk, tastefully chosen by Joe’s XYL to match the bedroom decor, holds a small Icom transceiver, a lap-top computer, and a small world globe. A pencil and yellow legal pad, now blank, are neatly placed in front of the transceiver. Joe flips on the Icom, tunes across the band and finding a clear spot, picks up the small hand mike, and calls a CQ. From amid static crashes and some weird squawks and squeals, he hears a K6 answering his call. He turns on the computer and logs the call into his database. The “six” is checking out a new rig and not interested in spending time in a rag-chew. After swapping reports and repeating his QTH two times—QRM, you know—they exchange 73s and the QSO is ended.  

Joe, rightfully so, is less than excited about the exchange of information. Joe decides to see what is happening on 2 meter FM. He picks up his HT and gives a listen to the repeater. It seems there is some sort of a practice drill in progress so the HT is placed back in its charger. Joe never cared much for CW. It is a lot like the technical stuff he had to study for his exam—a lot of work and effort. Putting the radios aside, Joe turns on the computer and checks his e-mail. Finding nothing in his mail but a few spam messages, most of which he deletes without reading, he shuts down the computer. “Nothing much interesting in here,” Joe muses to himself. He flips off his desk light and returns to the den to find out if he is, “smarter than a fifth grader.”

Now let’s visit Jim:

As old time BC announcers use to say back in the golden age of radio, “As we look in on Jim and Emma, they have just finished dinner. Emma is cleaning up the small, neat kitchen while Jim is enjoying his last cup of coffee of the day. Here they are . . .”

“Guess I’ll go down in the shop and do a little work,” says Jim. “I have a lot of cleaning up to do to get that place fit for human habitation again.” 

“I know,” replied Emma, “I was down there yesterday and your so-called Ham shack looks like the city dump.”

Being thoroughly familiar with the stairway leading down into his shack, Jim neglected to turn on the stairwell light, intending to turn on the big switch when he reached the bottom of the stairs. Unfortunately, he had forgotten about the old sweep generator he had picked up at the Junction City Hamfest. He was sure glad he had placed it on the floor at the bottom of the stairs; all the damage he suffered was a little skin peeled off his shin.  

“I just have to clean this place up before somebody gets hurt,” he said to himself as he pulled the sweep generator across the concrete floor to a vacant spot under his service bench. Jim looked around his basement shack. He was proud of the shack even though it could use a good cleaning. Years ago, he had painted the walls a light gray color so they would reflect a lot of light. His workbench was built to last, with 4 x 4 legs and a top made from 2 x 10 white pine screwed and glued to the 2 x 4 framework. A piece of tempered hardboard covered the white pine work surface.  

He liked such a surface to work on. When it became scuffed and scratched badly enough it was easy and inexpensive to replace. Rugged shelving attached to the concrete wall behind his workbench supported a variety of test equipment, most of which was surplus or out of date commercial equipment he had picked up at local Hamfests, and rebuilt into like new condition.  

Across the room from his workbench was his “operating position,” a desk twelve feet long of construction similar to his workbench. There was one exception: the surface of the desk was covered with a piece of green outdoor carpet. A number of rigs were always at the ready, including an R-390, Collins 75A4, an older Kenwood transceiver, and a variety of home-built projects. Heavy floor-to ceiling shelving on the wall under the stairwell held a number of classic receivers and transmitters. Jim’s favorite rig was a World War II Hallicrafters BC-610 transmitter and the Collins 75A4 receiver. This setup, in conjunction with his Johnson KW tuner and a dipole fed with 600 ohm open wire line, was a winner.  

Jim walked across the room to his operating desk and turned on the Collins receiver. Before starting his clean up he might have a QSO on 75 meter AM. Several of the AM boys were on. “Boy, what a signal old Steve from down inLubbockis laying in here tonight,” thought Jim. “Guess I’ll give him a short shout and see if he can hear this old 610.”  

Jim’s homebuilt SWR/Power meter indicated about 350 watts into the Zepp.  

“No use pushing this old Hallicrafters,” he thought. “Anyway, if you can’t hit ’em with 350 you just don’t need ’em.”  

Steve was running a Gates BC transmitter he had rebuilt. The class B modulation was a sound like no other—sound like the old AM stations used to pump out—clear as a bell. The QSO lasted almost an hour because several other AM-ers broke in. Finally Jim signed with the group, fully intending to start work cleaning the shack. He returned to his workbench and started sorting tools and parts putting them in their proper place.

“Now, I know better than to start two projects at once,” mused Jim. “Why did I not finish building this transmatch before I started restoring my HRO?”  

The HRO was an unexpected addition to Jim’s shack. For many years he searched everywhere from flea markets to the classified ads in Electric Radio hoping to find a nice HRO at a realistic price. When one showed up at the Wichita Hamfest for only $200 he could resist no longer. Jim inspected the near-perfect metal chassis of the HRO—he had been cleaning on it for several days. It seemed he had gone about as far as practical with cotton swabs and cleaning agents. With the cosmetics nearing completion it was time to start on the electrical restoration.  

“I think I’ll change a few by-passes in the HRO before bedtime,” thought Jim. “I’m really anxious to fire this old receiver up.”  

Close-up work such as soldering in new capacitors required concentration and was a strain on his eyes. Looking up, Jim removed his glasses and wiped his eyes with his handkerchief. Now he could see a little better, but decided he should quit the eye straining work for the evening. Glancing at the large wall clock he was surprised to see it was almost 11:00 p.m.  

“Guess I’ll close down the shack for tonight,” thought Jim, but then he had a better idea. “I think I’ll tune the little ‘Twinplex’ across the 20 meter band and see if it is still open.”  

The Twinplex, first written up by Hugo Gernsback in his Short Wave Craft magazine back in 1934, was a one tube (type 19 dual triode) regenerative receiver. In those Depression years the receiver was an instant success. Back then the Twinplex was available in kit form for less than four dollars, but many Hams constructed the little receiver from their junk box. After the initial publication of the Twinplex article featuring the newly introduced type 19 tube, (1933) similar construction articles were printed and reprinted. By the mid-30s almost every Ham in the world was familiar with the circuit. Recently, articles on the Twinplex by Dave Ishmael in Electric Radio magazine had aroused his curiosity. He could not resist the temptation to build one and see for himself if it really worked as well as everyone said. He found it did indeed work amazingly well.   

This is my version of the Twinplex. I am very proud to say that the set is now part of the Dave Ishmael collection.

Rear view of Twinplex receiver. The tube and coil have been removed to better show construction details.

For power, Jim was using two D cell flashlight batteries for the filament and eight 9-volt batteries in series for the plate. In this modern age we tend to forget just how quiet a battery radio is. Tuning across the band he heard several Europeans and one station in North Africa. One section of the 19 served as a triode regenerative detector while the other half of the tube was an audio amplifier. The little set had plenty of audio drive for a pair of good phones. When Jim turned off the Twinplex and pulled the big switch, the time was a few minutes past 12:00 p.m.   

“Time sure gets away from me,” said Jim to himself. “I suppose the shack can wait until tomorrow for a good cleaning.”  

Please bear in mind that Jim and Joe are real Hams, and although their style of operating is much different, they represent a sizeable percentage of our Ham fraternity. There are many other options of course, such as DX-ing, emergency communications, and UHF operating. The point is, Jim is getting much more from the hobby of radio than Joe, and that is unfortunate. Perhaps in some small way we can help Joe see ham radio from a different perspective.” 

The November 1930 QST featured this set in a lead article, with its photograph on the cover. In 1930 this was considered a good ham transmitter. Younger readers will think the title 'TNT Transmitter' means it is powerful. Not so. Two types of rigs were in common use at the time—the TGTP and the TNT. TGTP means the set uses a Tuned Grid—Tuned Plate circuit. TNT means Tuned—Not Tuned. A look at the breadboard construction shows that the plate circuit is tuned while the grid circuit is untuned—hence the name TNT.

Another view of the TNT which shows construction in more detail.



Thirteen Cents Well Spent

                                     I have never let my schooling interfere with my education.

                                                                                                          Mark Twain  (1835-1910)

By 1935 theUnited Statescould feel the economy starting a gradual uphill climb from the Great Depression. Oh, it was not that jobs were plentiful, or that prices were changing enough to be noticeable—it was more of a slight feeling of optimism throughout the country.

Gasoline was 20 cents a gallon, or less. For a few weeks I had a Saturday job pumping gas at a local filling station. Our gasoline was priced 17 cents a gallon or six gallons for one dollar. Bread from most bakeries was 10 cents a loaf; ice cream cones, double-dipped, still sold for five cents. Our best restaurant served a 16 oz. sirloin, with french fries and a nice salad for 90 cents. Most customers bought the 35 cent plate lunch.

When I lost my job at the service station, I went to work for a grocery store delivering groceries on Saturday. My job started at 7:00 am. Only one store in town offered free delivery, thus we had a very good business. Money was still ‘tight’ and most grocery orders were for less than ten dollars. Groceries were delivered in metal baskets about one third smaller than grocery shopping carts today. My orders were to always go in the back door, never knock or ring the doorbell, put perishables in the refrigerator and the other groceries on a table, and quietly leave. 

By 8:00 am delivery orders started coming in. By 10:00 am I had to work hard and fast to keep up. By 2:00 pm pure bedlam set in. Grocery orders to be delivered came to a stop about 8:00 pm. After the last delivery, all fresh produce was removed from the vegetable counter and it was scrubbed down with baking soda and chlorine bleach. 

The store was manned by the owner and butcher, his wife, his wife’s sister, a young male employee, and on Saturday a delivery boy. Through the week the deliveries were left to the young grocery clerk.

The store bought live chickens early Saturday morning from one of the many live poultry dealers in town. The two ladies, killed, plucked, and dressed out the two dozen chickens for sale. Needless to say, they had to arrive at the store well before the 7:00 am opening time.

By 9:30 pm we had the vegetable counter clean, the wood floor swept, and all perishables on ice. The final work for the day was finished, all but cleaning up the over-ripe produce and chicken guts and feathers. My last chore was to deliver the culled produce, and any other garbage, to a pig pen on a farm owned by the store owner. The farm was about two miles from town. 

When I returned from the pig farm my day’s work was finished. That was when I received my pay, a grand total of one dollar and fifty cents. My pay figured out to a bit less than ten cents per hour. I never got to enjoy one of those 90 cent sirloins—no meal was worth nine hours of hard labor.

A few years later I was in the Air Force, and sometime my duties seemed difficult. Whenever I felt sorry for myself, all I had to do was remember those Saturdays delivering groceries. Recalling those snowy, or rainy, winter days when I worked 16 hours in wet clothes for one dollar and fifty cents, the Air Force seemed much more bearable. 

Hugo Gernsback published a series of small 32 page booklets during the 1930’s. The books were all uniform in size with a bright yellow cover. They were small; 5 by 7 inches in size, which made it easy to read while in class or study hall by tucking them inside a text book. The books were priced at ten cents each—postpaid. The inside front cover and inside back cover advertising was reserved for Mr. Gernsback. It appeared that the only paid advertising was that of the National Radio Institute on the outside back cover.

My reprint book cost a bit over ten cents, about five dollars as I remember, but it is worth the cost as it brings back many memories. 

I owned the same book back in the mid thirties; ‘How to build 4 Doerle Short Wave Sets.’ There were other titles available; ‘All About Aerials,’ ‘How to Read Radio Diagrams,’ ‘Radio for Beginners,’ and ‘Beginners Radio Dictionary,’ were a few of the titles available.

I never got around to building all four sets featured in the book; I only built one, and it never worked. Failure to operate might be because I substituted 201A’s for the 30’s, and tried to operate the filaments off of a filament transformer. I did get a good loud 60 cycle noise from the phones. However, I got a lot more than ten cents worth of knowledge from the book. I replied to the back cover ad by Mr. J.E. Smith, President, of the National Radio Institute.

All I had to do was fill out the coupon with my name and address, and Mr. Smith would send me a sample radio lesson, plus a 64 page book describing all the opportunities in radio. My total cost would be three cent stamp.

Now I realize that most readers of Electric Radio will think my first lesson was something everyone knew already. Not so! I studied the lesson with a lot more attention than I studied my History and English books. The lesson told how to isolate radio problems using what Mr. Smith called ‘The Circuit Disturbance Test.’

Mr. Smith realized that most of those who sent in coupons would have little, if any, test equipment. Thus his first lesson taught you a bit about isolating problems in a receiver using practically nothing other than a short length of wire or a screwdriver. This evolved into what I later called the wet finger test.

This was ‘high tech’ stuff for a 14 year old boy. When you encountered a dead radio first be sure the electric cord and switch were OK. If the tubes and dial bulb lit up, then you knew the cord, plug, and probably the transformer were OK. At this point you started disturbing the circuits by touching the grids of the tubes, starting with the audio output stage. If this resulted in an audible 60 cycle hum you could, in most cases, consider the power supply, output stage, and all the associated components were working more or less as intended.

You then started working your way backward from the output stage, moving in what you hoped was the general direction back to the antenna input. With luck you might eventually find a circuit that no matter how much you ‘disturbed’ it, offered no response. I might mention here that there was a learning curve involved. 

I visited our town’s only radio repairman on a daily basis. The reason why he never threw me out of his shop was that I kept a respectful distance from his workbench, only occasionally breaking my silence with a comment or question—most of which went unanswered. In an effort to show him that I had a bit of knowledge of radio, I asked him if he used the ‘circuit disturbance test’ to isolate problems. He looked up from the chassis he had upside down on his workbench, “You mean this test?” he asked, as he touched his index finger to his tongue wetting it good, then touched the grid of the output tube. The speaker emitted a very loud sixty cycle hum.

The hum was much louder than what I had been hearing when I touched an insulated screw driver to the output tube. “Don’t that shock you when you touch the tube?” I asked.

“No. As long as I touch the grid, I am OK. You see there is very little voltage on the grid of this 2A3. I just remember to be sure and touch pin three,” explained the white-haired serviceman. I departed with a pleasant feeling that I was learning a lot about radio—someday I might turn all this knowledge into a profit. 

Not long afterward a neighbor stopped me as I was walking home from school. “Your dad was telling me that you are working hard studying for your Amateur Radio License. My radio was playing good yesterday. I was listening to the World Series ball game when all of a sudden the radio went completely dead. I kept trying to get it to work until I smelled something getting hot inside the radio.”

I tried to look like I knew a little about radio. “You did the right thing when you turned it off,” I said. “If something is overheating, leaving the radio turned on could cause serious damage. Let’s hope we find the problem, and no expensive part like a power transformer is burned out.” 

“I’d be glad to pay you three dollars if you can find the problem,” said the middle-aged gentleman. “If I have to take it to the shop it will cost me five dollars or more.”

With my new found knowledge, supported by the confidence of youth, I followed the gentleman inside his home, picked up the RCA 5T radio and carried it out the door. “I’ll work on the radio tonight and let you know something tomorrow morning,” I said with what I hoped was a note of confidence. I knew darn well that if I lucked out and got the radio working it would be little short of a miracle, but for three dollars I was going to give it my best shot.

I removed the chassis and speaker from the 5T radio cabinet. In those years we called it a ‘table set,’ today we call it a ‘Tombstone’ radio because of its cabinet shape. I first plugged the set in and prepared to administer my newly learned ‘wet finger test.’ Before I could do any testing, I noticed the plates of the 80 rectifier getting cherry red—there was no sound at all. I got out my ten cent book, How to build 4 Doerle Short Wave Sets. I remembered that the very last pages of the book told how to build a hum-free AC ‘power pack’ that used a type 80 rectifier. Obviously something was shorting out the HV from the power pack thus causing the 80 to overheat. With my $1.50, 100-watt soldering iron I removed the HV wire from one of the heater pins and turned the set on. Now the set, while still dead, showed no sign of overheating, I had to find what was causing the HV to suffer such a disastrous overload. With luck I found difficult to believe, I found the problem almost immediately. The HV lead was pulled tightly against a ground lug. I could see the wire was blackened where the HV lead rubbed the ground lug. Why the insulation broke down I’ll never know—but it was plain to see that as it now stood, the HV was directly shorted to ground. I had a roll of the old cloth ‘tire tape’ in my tool box. After wrapping the wire and re-routing it to a less trouble prone position, normal reception was restored.

I was reluctant to complete my first radio repair job that actually paid me money, without first applying my new found knowledge. I wet my finger and placed it on pin #2 of the 42. I can assure you that the power supply was working very well. The 300 volts ran up my arm, and I am sure my ears lit up like a Christmas tree, and yes, I did get a sound from the speaker—or perhaps it was simply a loud ringing in my ears.

I put the set back together and delivered it that night. The customer, and neighbor, gladly paid me $3.00. In little more than an hour I had earned more than I earned working two hard days delivering groceries. Word got around that I could repair radios and save customers a bit of money. Before long I quit the grocery job and made a modest amount of spending money working on radios. 

I also gained more knowledge; keep wet fingers off of tube socket pins when the set is turned on. If you must use a wet finger to test audio, first make sure you know what pins are connected to the plate and screen.

Today, I use a short length of insulated wire with an insulated test probe on one end and an insulated alligator clip on the other. This piece of test gear is almost as good an investment as the 10 cent Gernsback books.