Radio History in 1946

1946NovPMSeventy-five years ago this month, the November 1946 issue of Popular Mechanics carried this article about one of our favorit topics, namely, the history of radio. And the article highlights just how much had happened in the medium’s first quarter century or so. The first commercial radio broadcasts had taken place in 1920, and the first permanent nationwide network, NBC, was formed in 1926.

The magazine noted that when KDKA carried the first scheduled broadcast, the 1920 Harding-Cox election returns, there were only a handful of receivers in the nation. But when FDR addressed the nation less than 20 years later, there were more than a hundred million Americans listening.

Obviously, there have been many changes in the last 75 years, but by 1946, postwar broadcasting, of AM, FM, and television, is still recognizable to us today.



1946 PA Amplifier

1946NovPM1946NovPM2The accompanying article doesn’t say for sure, but I’m guessing the gentleman shown at the left made some serious extra income 75 years ago, thanks to the audio amplifier he built, based on plans in the November 1946 issue of Popular Mechanics.

The general-purpose amplifier put out 32 watts, and had enough power to drive four large speakers. It could be used in emergencies, or to provide music and public address for school groups or outdoor activities. It had two 6L6 tubes in push-pull configuration running class AB-1, and weighed in at only 22 pounds, with a plywood chassis.



1921 ABC Units Crystal Set

1921NovBLA hundred years ago this month, this savvy advertiser realized that scouts would be a huge market for the magic of radio. Wireless merit badge had been introduced in 1918, and radio was a young man’s game. This ad from the Wireless Equipment Co., Inc., of Newark, NJ touted the company’s ABC Unit detector.

The unit was a complete crystal set, but the name referred to the fact that it could be added to other units in a modular fashion. After starting with the crystal detector, a two-step amplifier could be added, or a vacuum tube detector could replace the crystal.

The booklet describing the set was only a dime, but the price of the set would have been out of reach of the impecunious scout. It sold for $24.50 which, according to this inflation calculator, works out to $375 in 2021 dollars.  The ad appeared in the November 1921 issue of Boys’ Life.



CB Radio on 77 Sunset Strip: 1961

1961NovPECoverSixty years ago this month, the cover of the November 1961 issue of Popular Electronics featured the stars of the hit TV private detective drama 77 Sunset Strip.  Roger Smith and Efrem Zimbalist, Jr., are shown with a new co-star, namely CB radio. Smith is shown at the mike of a base transceiver, and Zimbalist is shown with a handheld unit. The base unit looks like it might be a Polytronics Poly-Comm Model N.

The magazine was proud to announce that it had been consulted relative to placement of CB radio on this network program. The detectives used a phony call sign, 11J5486. The format for the call was right, but the letter would have been W. But the number 11 was correct for southern California.

The magazine reminded readers to tune in to ABC on Friday night at 9:00, especially for the following episodes which prominently featured the CB equipment: The Bridal Trail Caper (season 4, episode 20),  The Bel Air Hermit (season 4, episode 22), The Unremembered (season 4, episode 6).

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Lee’s Record & Radio Shop, St. Joseph, Mo, 1946

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Shown here, as it appears today and as it appeared 75 years ago, is the corner of 6th and Francis St., St. Joseph, MO.  Today, it’s the office of an insurance company, but 75 years ago, it was Lee’s Record & Radio Shop, profiled in the November 1946 issue of Radio Retailing.

The rent was high, but the street traffic was heavy, so the store took advantage of a big eye-catching display to lure customers into the store. According to Tillie Frankhauser, the manager, the store was spectacularly in the black. The corner was the second busiest in the city, and owner Lee Drowther took advantage of it. The store was self-service, with albums lined up on the shelf in eye-catching displays. There were two types of listening booths, a stand-up type for quick appraisal of a record, and leather trimmed enclosed booths for serious listening. Plans were in place to construct a mezzanine area for demonstration of radios.

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Getting Started in CB Radio: 1961

1961NovPEBy 1961, it was clear that the 11 meter Citizens Band was a hit. Popularity hadn’t hit the frenzied levels of the 1970s, but it was becoming popular, especially by those with some background in electronics. The 27 MHz band had been allocated to Class D CB in 1958, and in three years, much equipment was available on the market.

The November 1961 issue of Popular Electronics carried a primer for those thinking about getting into CB radio, penned by prolific electronics writer Tom Kneitel. He gave basic advice on radios, antennas, operating, and licensing.

The article’s byline contains his CB call sign, 2W1965. CB calls at the time were in this format, starting with a number showing area of the country where licensed. The map showing those zones graced the magazine’s cover. This was followed by the letter W, and then a serial number.

A few years later, the format changed to three letters (later four) starting with K, followed by four digits.



Everyone Can Listen In! 1921

1921NovPSA hundred years ago, radio was definitely ready for prime time, as made clear by the cover of the November 1921 issue of Popular Science.  This father-son team had caught the radio bug, and they were apparently Giants fans. The newspaper indicates that they’re listening to the final game of the 1921 World Series, which the Giants clinched on October 13.

The accompanying feature article by Armstrong Perry telling how he listened to the world, and how easy it was for others to get into the radio pastime. The magazine noted that radio was catching on like wildfire.  There were a million fans already, and the thig had just started.

When he started, Perry thought of radio as something like a fire extinguisher on a lifeboat–something for use only in an emergency. But once he tried it out, he was in for a great awakening of the romance of radio. A friend talked him into buying the cheapest possible receiving set, consisting of a detector, headphones, and some wire for aerial and ground. The second he hooked it up, he heard jazz through the headphones and was hooked. He also heard Morse code, and when he started hearing the same patterns at the same time each night, he wrote down the dots and dashes, and was able to translate the first message:

QST QST QST de NAH NAH NAH.

Amateur Broadcast: If you are interested in this broadcast, please advise by mail, United States Navy, Radio Amateur Bureau, New York.

At once, he wrote a letter saying that he was very much interested. He received a form to return, and was soon registered as an amateur.

One night, to my astonishment, I found my own name at the beginning of a message. Imagine the thrill with which I took out of the air a reply by the Navy Radio Amateur Bureau to a letter I had written them the day before! Let me tell you that it’s the thrill of a lifetime when your government first communicates with you direct by wireless, and you get the message out of the air yourself.

Perry writes of some of the other thrills of the airwaves, such as hearing an SOS, and then hearing announcements by NAH to clear the air for the emergency traffic. You can read more on that subject at this post.

The article author, Armstrong Perry, was also an official of the Boy Scouts of America, and was the author, the same month, of a letter to the editor of QST promoting another service offered by NAH. Every Wednesday evening at 9:30 PM Eastern Time, the station transmitted on 1500 meters a special bulletin for scouts. It was transmitted by spark at 10 words per minute, and Perry pointed out that all scouts learned the Morse code. You can find more information on these broadcasts at our earlier post.

The magazine undoubtedly expected that many would be bit by the radio bug by Armstrong’s article, and the magazine promised forthcoming articles on building a set.



Which is Cheaper: Gasoline or Ethanol?

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Gasoline versus Ethanol

Shown above is a molecule of ethyl alcohol, also known as ethanol.  If you ignite it with a spark, it will burn. This is not rocket science.  (Come to think of it, though, if you use it as rocket fuel, then it is rocket science.)  Gasoline (or petrol, as our friends across the pond like to call it) is a mixture of molecules, most of which look very similar to the one above. If you ignite it with a spark, it will also burn. The difference, however, is the “O“. Gasoline doesn’t have any oxygen atoms. To burn it, you need to supply all of the oxygen from another source. Fortunately, that’s easy to do, since we live in an atmosphere consisting partly of oxygen, and it’s free for the taking.

But this means that for a given amount of fuel, the ethanol will have less energy content: If you burn gasoline, you can use the free oxygen that is floating around. If you use ethanol, then you are paying for some of the oxygen, which you could have gotten for free.

For this reason, I’ve heard many people explain that you shouldn’t use ethanol as fuel, because your fuel mileage will be lower. But that’s not the end of the discussion: If you’re like me, you are really concerned about saving money, and your main concern is which fuel is cheaper.

A Real World Comparison Test

MSPEscanabaI’ve heard many persons express their opinion as to the relative fuel economy, but I’ve never heard anyone actually test it, so I decided to do so myself. I recently had to drive from St. Paul, MN, to Escanaba, MI, to do an FCC Great Lakes Ship Radio Inspection. I drove eastbound using e85, a mixture of approximately 85% ethanol and 15% gasoline, and drove westbound with gasoline (which is actually e10, 90% gasoline and 10% ethanol). For the nitpickers, here are the conditions of the test:

To make sure I was able to purge almost all of the E85 from the system before the return trip, I tested the mileage from St. Paul, MN, to Marinette, WI, short of my final destination. I started with a full tank, and upon arriving in Marinette, I checked the cumulative mileage and then added about 6 gallons. I also added a few gallons in Escanaba, MI, about 56 miles away. When I arrived back in Marinette, I was down to about a quarter tank, at which point I filled with gasoline (actually, e10) for the trip home. So almost all of the e85 had been purged from the system for the trip home.

My vehicle is a 2014 Dodge Journey with the 3.6 liter 6 cylinder engine. The EPA estimated highway mileage is 25 MPG with gasoline, and 18 MPG with e85. The two endpoints have similar elevations (795 feet in St. Paul, versus 594 in Marinette). Winds on the day of my trip were light, and whenever I did see flags moving in the breeze, the prevailing wind seemed to be from the north. So there should be no effect from a headwind or tailwind. I took an identical route both directions, mostly over four lane freeways, but a small portion over county highways suggested by Google. In other words, the driving conditions both directions were more or less identical. The average mileage reading was taken from the car’s computer, which was reset after each fill-up.

The average mileage using e85 was 21.6 MPG. The average mileage using gasoline (actually e10) was 26.4 MPG. As noted above, the mileage with ethanol was lower, since the fuel has a lower energy content. The real question is which fuel is cheaper.

To make the comparison fair, I’ll use the prices at the same station, the one where I bought the e85: The e85 cost $2.229 per gallon. In other words, it cost me $2.229 to drive 21.6 miles, or 10.32 cents per mile. (I actually used a loyalty card, which brought the cost down to $2.029 per gallon, or 9.4 cents per mile).

The gasoline I bought for the return trip cost $3.239 per gallon, since one gallon allows me to drive 26.4 miles, that means I spent 12.3 cents per mile. But in fairness, if I had bought that gas for the eastbound trip at the same place where I bought the e85, it would have cost $3.099 per gallon, which works out to 11.7 cents per mile.

In other words, it was cheaper to drive using the e85: 10.3 cents per mile versus 11.7 cents per mile. In other words, the e85 is 12% cheaper than using gasoline.

It should be noted that these figures are based upon the price at one particular station, a Holiday gas station.  You can view the current prices at this station at this link.  Some gas stations sell e85, but at a much smaller discount over the price of regular gasoline. In fact, I’ve occasionally seeing a station inexplicably selling e85 for more than the price of regular gasoline. Obviously, it makes no sense to buy to buy there. To be economical, the price of e85 needs to be below 21.6/26.4 = 82% the price of regular gas. In my case, the price of e85 was 74% the cost, and thus a clear bargain.

Other Considerations

There are a couple of other factors to keep in mind. Even though the name of the fuel is “e85” the exact blend can vary. During the winter months, the gasoline content is higher, and I have noticed that stations do not adjust the price based upon the exact mix. So during the winter, the e85 might be an even greater bargain.

Also, I have not measured it, but I have noticed that when I have a mixture that is around 50% ethanol and 50% gasoline, I don’t notice much mileage difference between it and 100% gasoline. So even though the energy content is lower, the actual effect on mileage might not be linear. It would be interesting to repeat this experiment with different blends.

I’m not sure of this, but I suspect that for applications requiring more power (such as towing), gasoline would have a greater advantage. But again, I’ve not tested this hypothesis.

And you will certainly have more range using gasoline than you would ethanol. So if cost isn’t an issue, but you need to drive as far as possible before refueling, then you will be able to drive 22% further by using gasoline.

I suspect that ethanol might have a greater cost advantage for high altitude driving. The reason why there is a lower energy content is because the fuel contains oxygen, which is available at no cost from the atmosphere. At higher elevations, the additional oxygen in the fuel might be an advantage.

Precisely because it has a lower energy content, ethanol also increases the octane rating of the fuel, so it is an inexpensive option for use in high compression engines.

Ideas for Young Scientists

If students are looking for an interesting science fair project, I hope my little experiment has given you some ideas. Even if you don’t have a driver’s license, you can recruit your parents to keep track of mileage when driving, and compare different fuels, or different types of driving, to see which is the most economical.

Interestingly, I exceeded the EPA mileage estimates for both fuels. There was a time when the EPA estimates were overly optimistic, but I guess those days are gone.

But Ethanol Will Clog My Fuel Filter!

Someone will invariably claim that ethanol clogs fuel filters, and I want to explain what is really happening.  Alcohol can mix with both water and gasoline.  Water, by itself, cannot mix with gasoline.  If you have 100% gasoline in your tank and some water is added, it is heavier than gasoline and will settle to the sump at the bottom of the tank, which is below the point where it can be drawn out by the fuel pump.  It doesn’t do any harm there, as long as it stays below the level of the fuel intake.  But it does dissolve dirt, and that dirt has nowhere to go but stay in the water.

Eventually, if water keeps getting added, it will continue to collect.  If it ever gets up to the level of the intake, then this will be a problem, since water mixed with dirt will be going to the engine rather than gasoline.  The fuel filter will clean out the dirt, but the engine will try to burn the water, and water doesn’t burn.

When ethanol was first added to gasoline in the U.S., this meant that it found its way, for the first time, into cars with water in the bottom of the tank.  The alcohol allowed the water and dirt to mix with the gasoline.  The dirt, which may have collected since the car was new, went into the fuel filter, as the filter was designed to do.  This is how ethanol got a reputation for clogging fuel filters.

But now, virtually all gasoline sold in the U.S. contains at least 10% ethanol, and virtually every car on the road has been burning 10% ethanol for years.  Water never gets a chance to build up in the tank.  If there is dirt in the tank, it comes out constantly.  Unlike the time the car got its first tank of ethanol, years’ accumulation of dirt is not coming out all at once to suddenly clog the filter.  So after that initial shock, ethanol actually corrects the problem, and also prevents gas line freeze.  In the days before ethanol fuel, in cold climates, people bought a product called Heet to prevent fuel line freezing.  This consisted either of ethanol or isopropyl alcohol.  Since ethanol is now included in the fuel, this is no longer necessary, and you rarely hear of gas lines freezing.



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1991 Halloween Blizzard

Today marks the 30th anniversary of the Great Halloween Blizzard of 1991.  In Minneapolis-St. Paul, snow started falling in the late afternoon. By midnight, 8.2 inches had fallen, a record for that date, and also for the entire month of October. Before the snow stopped falling three days later, Minneapolis-St. Paul had received 28.4 inches, and Duluth 36.9 inches.

Twenty-two persons died in the storm, which was followed by record cold temperatures that hindered snow removal. Schools were closed the following day, a Friday, with some remaining closed the following Monday.

Trick or treating was largely a victim of the storm. At the time, I lived in an apartment building, so had a handful of kids from the building trick or treating.  But for most, the traditional activity was impossible.

You can view WCCO-TV coverage of the storm at this video, posted courtesy of TC Media Now:



Science Fair Project: Homemade Battery

1961OctPE1If Junior is looking for a project for the science fair, a good standby is always making a battery out of materials found around the house. We’ve previously covered the idea in more detail, but the October 1961 issue of Popular Electronics shows a slight variation. All of these are a variation of Allesandro Volta‘s Voltaic pile from 1799, and are easy to recreate.

This one uses strips of copper and aluminum. The mechanical details are unimportant, so you don’t have to worry about the exact shape. The aluminum can be cut from a soda can, although these have a plastic lining on one side and paint on the other, so the aluminum will need to be sanded. If you don’t have a strip of copper available, a piece of copper wire, or any kind of copper hardware found at your local hardware store will work fine.

The 1961 article uses the battery to power a one-transistor radio. As you can see below, it consists of a crystal set with one germanium transistor amplifying the audio. But to show that the battery is working, a light emitting diode would work just fine. Polarity is important, so if it doesn’t light at first, simply reverse it in the circuit. In this battery, the copper is positive, and the aluminum is negative. It will come to life when the two electrodes are placed in salt water. As shown in this picture, you can carefully put one drop between the electrodes, or simply place it upside down in a glass of salt water.

Junior’s experiment for the science fair can be to see how much salt in the water results in the brightest glow. Or he or she can try different electrolytes, such as bleach or lemon juice. Very little can go wrong, and as long as some liquid is between the two strips, the LED is almost certain to give off a little light.

As we noted previously, the project is very easy with materials found around the house.  But for students who want to bypass the procurement process, you can simply go out and buy one of the potato clocks shown at left.

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