Monthly Archives: November 2020

1960 One Transistor CB Receiver

Sixty years ago, this New York scout made the front cover of the November 1960 issue of Electronics Illustrated by demonstrating this one-transistor superregenerative receiver for the 11 meter Citizen’s Band.

According to the accompanying article, a pair of CB transceivers would set you back about $150. But for many uses, one-way communication was sufficient. The example shown on the cover was “the Boy Scout out on a hiking expedition who wants to tune in home camp.” In addition, the article suggested that a physician might carry a small receiver on a large hospital campus to be paged. Or a TV serviceman working on a roof antenna could hear instructions from the ground.

This simple circuit would satisfy all of those needs. According to the article, the set would provide clear reception up to three miles without fading.

1940 Motorola Bike Radio

Eighty years ago, this cyclist was able to enjoy her favorite program no matter where she happened to be pedaling, thanks to this three tube set shown in the November 1940 issue of Popular Science. The set had a loudspeaker that faced the rider, and included an antenna that attached to the tip of the front fender and curved back. A separate battery box, supplying 90 volts B+ and 1.5 volts for the filaments, clamped securely to the bicycle frame.

While not identified by the magazine, the set appears to be a Motorola model B-150, featuring a tube lineup of 1A7GT,3A8GT, and 1Q5GT. If the set looks familiar, it’s probably because we previously featured it in connection with an ad allowing boys to win a free example by selling subscriptions to Radio Guide magazine.

Since this cyclist clearly isn’t a boy, she presumably paid the retail price of $19.95.

1940 Grocery Prices

Here’s a snapshot of what grocery prices looked like 80 years ago, from the November 14, 1940, issue of the Pittsburgh Press.

When you look at these old prices, one way to translate them to modern prices is by remembering that each dollar was made up of ten silver dimes or four silver quarters. Either way, it was one ounce of silver. Today, the price of silver is about $24 per ounce, so if you multiply these prices by 24, you’ll get the rough modern equivalent.

Chicken would set you back 29 cents a pound, which would be about $7 a pound in today’s money. Ham was 19 cents a pound, or the equivalent of about $4.50 today.

Fish from Lake Erie was 25 cents a pound. You could buy it fresh, or for the same price, you could buy it cooked, and warm it up at home. At the lunch counter, a meal of either halibut or ham would set you back 56 cents for two people.

1970 Soviet Fax Machine

The magazine doesn’t show all of the construction details, but if you want to be accused of Russian meddling in the science fair, here’s the project for you. For the young Soviet comrade wishing to take home the blue ribbon in the oblast science fair, the November 1970 issue of Юный техник (Young Technician) magazine gave enough information to build a fax machine. Apparently, it was called a “phototelegraph-integrator”, since that is the title shown here.

Both of the drums are spinning at exactly the same speed. A scanner is moving across one of them, and a printing element, such as a pen, is moving across the other one, at exactly the same speed. One of the machines scans a picture of the word Mir (peace), and this is transmitted to the printer, which makes an exact facsimile.

The bright American student can also build a device that can transmit pictures through a wire. The key is to have two drums that are spinning at exactly the same speed. The easy way to accomplish this, for demonstration purposes, is to simply have both of them revolving together on the same shaft. Both of them need to have something that moves along the drum at exactly the same speed. The easy way to do this, for demonstration purposes, is to have the sending and receiving elements connected together with a shaft.

One of those elements needs to have a method to detect the picture. In a fax machine, that’s done with light. But an easy way to do it, for demonstration purposes, is to create the image using aluminum foil. Then, the sensor can be nothing more than a piece of wire that comes into contact with the foil.

This wire is hooked to a circuit which operates a solenoid. The solenoid raises and lowers a pen which comes into contact with the other drum. Whenever the wire on the sending drum comes into contact with the foil, the circuit is closed, and the pen starts drawing on the other drum.

Turn the drum while slowly moving the two sensors. The result will be a drawing exactly the same shape as the piece of foil.

The crude drawing below shows the general idea. An advanced student should be able to work out the invariable bugs and build their own fax machine. When you take home the blue ribbon, the other students will probably accuse you of winning due to Russian meddling. When they do, point out that there was nothing in the rules prohibiting it.

1950 Hi-Fi Demonstration Console

Eighty years ago, this intriguing room could be found at Allied Radio in Chicago. Here, the Hi-Fi enthusiast interested in the very best equipment could be given a demonstration showing exactly how different pieces of equipment would sound together. Around the room were various tuners, amplifiers, preamplifiers, cartridges, tape machines, and other devices. From the console, different elements could be switched into and out of the circuit, and the discerning listener would be able to pick out exactly the right combination that met their needs.

The photo appeared on the cover of Radio & Television News, November 1950, which also included an article going into the room’s technical details.

Armistice Day Blizzard: 80th Anniversary

Armistice Day Blizzard, Excelsior Blvd., West of Minneapolis. Minn. Historical Society photo, NOAA.

Wednesday, Veterans’ Day or Armistice Day, is the 102nd anniversary of the end of World War I. But in Minnesota and the Upper Midwest, it is remembered as the 80th anniversary of the Armistice Day Blizzard of 1940, which was responsible for taking 145 lives. Here are two previous posts about that blizzard:

Newton “Jack” Baker III, 1920

Shown here is Newton D. “Jack” Baker, III, the son of U.S. Secretary of War Newton D. Baker.

The picture appeared a hundred years ago this month in the November 1920 issue of Radio News, which reported that he had studied radio telegraphy enthusiastically, and had mounted this portable set on his bicycle, on which he listened while riding around Washington. With just the frame of the bike as an antenna, he was able to pick up NAA Arlington.

If Master Baker and his radio look familiar, that’s because we’ve seen both of them previously. He had been an exceedingly good boy during 1919, and Santa Claus brought the radio as a reward, as shown in this close-up from the picture we previously shared. This photograph is clearly the same boy, the same radio, and even the same headphones as the Christmas photo.

I don’t see any record of Baker having received an amateur license, but it appears that he was an enthusiastic listener in the earliest days of radio.

A Career in Wireless: 1920

A hundred years ago this month, the November 1920 issue of Boys’ Life asked scouts to ponder the question of whether they should pursue a career in radio.

The article was an excerpt from the merit badge pamphlet for “Wireless Electricity.” I’ve never run across this name before, but it’s used throughout the article. According to Wikipedia, Wireless merit badge was discontinued in 1923 and replaced by Radio, and I didn’t find any reference to the name Wireless Electricity.

The article talks about the advantages of a career in radio, such as the possibility of traveling the world as a shipboard radio operator. It also points out that there was a demand for persons to fill these lucrative positions. While the article pointed out that there were a number of good schools, it also made clear that most in the profession were self-trained as amateurs, and that this was one of the rare cases where one could get a good job based on such self-education.

The magazine also included some pointers for building a detector, shown at the bottom of the page.

Product Review: Opinel Pocket Knife

Bottom Line: The Opinel is a very inexpensive and unpretentious high quality knife for your everyday carry needs.

Pre-pandemic, I very rarely carried a pocket knife. When I needed a cutting tool, I looked around the garage or kitchen and found something suitable. In the car, I would find a cheap utility knife in the toolbox which would usually serve the purpose.

But with the pandemic, it seemed that I needed a knife multiple times per day. More often than not, it was to open a box from Amazon or Walmart. I like to do this outside, so that I can immediately discard the outer packaging into the recycling bin. Thus, it became convenient to keep a knife in my pocket. I had several around the house, many of which had been given to me as gifts over the years. The first one I stumbled upon was the Opinel No. 6 Stainless Steel folding knife.

As you can see from the picture, the Opinel is a nondescript knife with a wooden handle. It looks like a tool, which, of course, is exactly what it is. It doesn’t have a camouflage handle. It doesn’t have a built-in screwdriver or can opener. It’s benign looking, and designed for cutting things, a goal which it accomplishes remarkably well. It’s well made, and it seems to keep a cutting edge well. I’ve sharpened it a couple of times with a whetstone, and the edge seems to last.

My version came in stainless steel, and the knife is also available in carbon steel. Apparently, the carbon steel blade holds an edge a bit better, but is more prone to rust. The stainless steel (marked on the blade in French, Inox, short for inoxidable) seems the more practical choice.

The Number 6 in the product name indicates the length of the blade, the number 6 being 2.87 inches. The sizes range from a tiny Number 2, up to a Number 12 with a 4.84 inch blade. The number 6 seems to be the perfect size for the occasional jobs I use it for. In addition to opening boxes, I’ve used it to cut food while camping, strip wire, cut cords, and do the normal variety of tasks for which one would use a pocket knife. It’s big enough to do the jobs I need it for, but as it weighs only about an ounce, I hardly notice it in my pocket. The blade meets the “under three inches” standard which is important for some regulatory purposes. (On the other hand, at such time as it becomes safe to fly commercially, I’ll have to remember to leave it at home or in my checked baggage.)

Locking mechanism. Wikipedia photos.

The knife has a simple locking mechanism, which allows the blade to be locked open or closed. It’s simplicity itself–namely, a notched ring which can be twisted to hold the blade in place. In my opinion, most locking mechanisms are annoying and dangerous. If you’re using a knife in such a way that the blade might inadvertently close, then in my opinion, you are using it wrong. And most locking mechanisms I’ve seen require some contortion to disable them, such as holding down a button while moving the blade toward your finger. In most cases, in my opinion, the “safety” feature of a locking blade makes the knife less safe. In the case of the Opinel, however, the locking mechanism needn’t be used at all. In fact, I carried the knife around for quite some time before even realizing that the blade could be locked.

On the rare occasions when I might want to lock the blade on the Opinel, the mechanism and easy and safe to use. You merely rotate the ring to lock or unlock the blade.

Joseph Opinel began making knives in 1890 in Savoie, France, and the knife has always been the quintessential working man’s knife. Picasso reportedly used one as a sculpting tool. Today, about 15 million knives per year roll off the company’s assembly lines.

The Opinel knife is quite inexpensive, but high quality and useful. It’s unpretentious and looks like a tool, so it won’t draw the ire of those who are squeamish about knives. It’s the perfect knife to keep in your pocket. You’ll find you wind up using it several times per day.

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1945 Selective Crystal Set

Seventy-five years ago, this crystal set experimenter was pulling in a station, even though he was in a congested radio area, and even though there was another strong station very close to it on the dial. He was able to do this thanks to the crystal set shown in the November 1945 issue of Popular Mechanics.

The set featured two tuned circuits to give it such good selectivity. It was mounted on a chassis made of wood, and the two coils were mounted below the chassis. They could be wound on cardboard tubes or on wooden dowels.

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