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1962 License-Free Projects

1962MayEISixty years ago, the May 1962 issue of Electronics Illustrated featured these two projects to build unlicensed devices for use on 11 meters. The first is the walkie-talkie shown at the top. The three-transistor transceiver was powered by two mercury batteries. It’s 100 milliwatts were said to have a range of about 1000 feet.

The other project is a transmitter to be installed in a model rocket, weighing in at only 1-1/8 ounces, including battery. It had a range of about 1500 feet. The circuit was shown for 11 meters, where it could operate license fee, but the magazine also pointed out that good results were had on 10 or 40 meters for licensed hams.

Various types of telemetry could be used, but to start, the magazine recommended a photocell, mounted near a small hole in the side of the rocket. This would allow a measurement of the rocket’s spin, since it would oscillate in time with the photocell pointing at the sun.

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1947 Tom Thumb Portable

1947MayRadioRetailingIf you were wondering what the most wished-for radio of 1947 was, this was it, at least according to the manufacturer, the Automatic Radio Manufacturing Co., 122 Brookline Avenue, Boston.

The radio in question was the Tom Thumb portable, a four-tube (plus selenium rectifier) portable that came with its own rechargeable battery, undoubtedly a two-volt lead-acid cell. It could operate off battery, AC, or DC, and the battery could be charged internally (but now with the radio playing).

It was rather pricey, at $47, the equivalent of over $600 in 2022 dollars.

The ad appeared in the May 1947 issue of Radio Retailing.



1937 Built-in Radio

Screen Shot 2022-04-28 at 12.36.09 PMEighty five years ago, this couple are enjoying the luxury of a built-in radio, thanks to a little ingenuity by a reader of Popular Mechanics, who sent in this idea for the April 1937 issue.  A reader took one of the magazine’s designs for an AC-DC midget receiver, modified the panel dimensions slightly, and built it into a modernistic bookcase.



1942 Radio Programs

1942Apr27PghHere’s what you would have heard on the radio 80 years ago today, from the Pittsburgh Press, April 27, 1942. In addition to the broadcast band listings, the paper carried shortwave listings for programs from Moscow, London, Rio de Janeiro, Vatican City, Lima, and Guatemala City.

To see a larger version, click on the image above.



1950 Census

Census data about individuals is private for 72 years. I assume that the thinking is that after 72 years, nobody really cares how much money you made or other details of your personal life.  So after 72 years has elapsed, the information becomes public data.

Since census day was April 1, 1950, this means that the data for the 1950 census was made available on April 1, 2022. The census data for 1940 has been available online for ten years, and you can easily search it by many criteria, including name, at this link at Ancestry.com.  (In fact, if you just Google the person’s name and “1940 census,” you’ll probably find the data that way. All of the original images of these records are available at the U.S. Archives website, but they cannot be searched by name on that site.

The images of the original 1950 records are now available at the U.S. Archives, which promises that the records can be searched by name. However, since most of the records are in cursive writing, the OCR process is not yet quite up to the task. However, it promises that the Artificial Intelligence is going to engage in machine learning. In particular, users are requested to transcribe entries, and I believe the thinking is that the AI is going to use these examples to learn the handwriting of individual enumerators, the people who went door to door writing down the data about the people at each house.

If you do try to search by name now, you’ll need to use a little creativity.  In many cases, the last name is transcribed wrong, in which case you probably won’t find it.  But if you search for just the first names in such a case, you might find the household, especially if you can narrow down the location well enough.  But as the 1940 data proves, the searchability of the 1950 data is bound to get much better.

It took some searching, but I found my parents and grandparents. It was necessary, however, to know their address in 1950, at least approximately. Once you know where someone lives, you can find their “Enumeration District” with the interactive map at Ancestry.com.

Armed with this information, you can enter the Enumeration District, County, and State at the Archives.gov website.

You will then find a listing of all of the households in that neighborhood. Most of those listings seem to be about 25 pages long, and they are organized in the order in which the enumerator walked through the neighborhood knocking on doors. After you see which end they started on, it’s usually fairly easy to guess about which page the person of interest is on, and scroll through the pages to find them.

The example above is for then-Congressman Gerald R. Ford at his home in Washington, D.C. Since he was a member of Congress, the information for his household is struck out, with a notation that it will be transferred to his home district in Michigan.

The census contains the basic biographical data for everyone in the country. For about one person out of five, the enumerator was instructed to ask a few additional questions. My mother was one of those five people, and from her entry, I learned that in 1949, she earned a salary of $1600 per year working 41 weeks as a stenographer.



1962 Metal Detector

1962MarElectronicsWorldSixty years ago this month, the March 1962 issue of Electronics World showed how to put together this five transistor metal detector, using either 2N188A or 2N524 transistors. While these PNP germanium transistors are probably no longer manufactured, there are New Old Stock (NOS) specimens still to be found. However, the circuit is quite common in cheap metal detectors, and it’s probably most cost effective just to buy one from one of the links below.

If you’re looking for a very basic kit to build, the final link below is a one-transistor oscillator, which you use in conjunction with an AM radio for a rudimentary metal detector.

This type of metal detector is often sold as a toy, and the kids soon lose interest, or the parents confiscate it because of the annoying squeal. But they can actually work quite will, with just a bit of patience and practice.

This beat-frequency circuit consists of two identical oscillators, both tuned to the same frequency of about 100 kHz. One of them uses a coil mounted inside the case, and the other uses the search coil. When a metallic object comes near the search coil, that oscillator changes frequency. You start by tuning both to the same frequency, meaning that they become “zero beat,” and no sound comes out of the speaker. But when one oscillator changes frequency, and audio tone is heard, its frequency being the difference between the two oscillators. As long as you tune it carefully to zero beat, this type of detector is very sensitive. They’re regarded as toys because most kids don’t bother with the careful tuning part.

The secret of using this type of metal detector is to practice.  Toss some metallic objects on the floor, set the unit so that the tone just barely disappears, and then see how it reacts to those objects.  You’ll normally find that occasional re-tuning is necessary as the batteries get lower.

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1962 Clown Radio


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1939JanPSWe previously showed you a radio at left that was sure to delight the youngsters of 1939.  It featured a creepy face with eyes that lit up in time with the music.

Not to be outdone 23 years later, the publishers of Popular Mechanics published in the March 1962 issue the plans for the same general idea shown here. This time, the face, a clown, was a little bit less creepy, but it still had magic eye tubes in the place of eyeballs, and the eyes flashed in time with the music. The magazine gave two options for the project. If you didn’t have a radio to spare, then you could build the entire radio, which was basically a crystal set using 1N34 diode, with two tubes to provide loudspeaker volume. The magazine noted that this worked satisfactorily in downtown Chicago, and pulled in three different stations with a 50 foot antenna on the roof. According to the magazine, this simple circuit was “the minimum performance which might satisfy youngsters.”

But for better performance, it was recommended to just use an existing radio, and tap in the additional circuit, shown below, to flash the eyes. The magazine showed a template for cutting the clown face, but also noted that the prepunched chassis and clown face were available from the Experimenter’s Supply Co., 1924 W. Columbia Avenue, Chicago.

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Lancaster County Seed Co, 1937

85 years ago, if you were an impecunious boy, girl, man, or woman, and wanted some luxury items in your life, then this advertisement would certainly appeal to you. You could earn any of the prizes shown on this page, with absolutely no cost other than a little old fashioned initiative. You could do this by getting into the seed business, and that was as simple as filling out the coupon and mailing it back to the Lancaster County Seed Company of Paradise, PA. Or if you were truly thrifty, you could copy the information on a penny postcard and get started that way.

No money had to change hands. The Lancaster County Seed Company trusted you, and as soon as they received the coupon, they would send you 24 beautifully colored packets of “Garden Spot” Seeds, which everybody planted, according to the ad, and they were guaranteed to grow. You would sell them for a dime each. Lots of people would buy five to ten packets. In fact, your own family, along with a few friends, would buy all of them.

After you sold the seeds, you would get a money order for the $2.40 proceeds, along with your prize selection. With the exception of the wrist watch, you could have any of the prizes shown on this page: The musically inclined could chose between the guitar, ukulele, or guitar. Sports enthusiasts could get the basketball or roller skates, or even the air rifle. The moving picture machine or spy glass would undoubtedly appeal to many boys. And the practically minded could chose between the bed spread, the curtains, the cooking set, or the clock. For those with their eyes on the wrist watch, they could pay an additional 99 cents, or just sell another 24 packets of seeds.

The ad emphasized that the company trusted you, and there was no need to send any money. Most of the entrepreneurs who signed up probably fulfilled their obligations, but this site shows a letter from the President of the company to those who didn’t promptly return the money. According to the letter, “we know you are perfectly honest and will want to pay whatever you owe.” It reminded the recipient to get a money order from the post office or RFD carrier and send it back right away. If the seeds hadn’t all been sold, then “you should make a final effort to do so.”

The letter assured the recipient that as soon as the money was in hand, the premium would be sent. For those who had given up hope, the letter asked them to send a money order for what they had sold along with the remaining seeds in good condition, and the company would follow through with a premium for the amount of work which you had done.

The ad appeared 85 years ago this month in the February 1937 issue of Radio Mirror.



中文圣经

For the time being, anyway, this website is apparently not blocked in China. We decided to take advantage of that fact and post the entire text of the Bible in Chinese. This text is in the public domain, and you can find the original at this link. To download the Bible, click this link, which is a ZIP folder. Find the file “index.html” and start from there. The following is an automated translation of this paragraph:
就目前而言,无论如何,这个网站在中国显然没有被屏蔽。我们决定利用这一事实,用中文发布整本圣经。此文本属于公共领域,您可以在上面的第一个链接中的英文描述中找到原文。要下载圣经,请单击上面的第二个链接,这是一个 ZIP 文件夹。找到文件“index.html”并从那里开始。

1952 Boys’ Life Transmitter

1952JanBL1952JanBL2Seventy years ago, the Novice license was new, and Boys’ Life took full advantage by showing scouts how they could get on the air. The January 1952 issue showed how to put together the one-tube 80 meter CW transmitter shown here. A previous issue had shown a suitable receiver, and the next month’s issue would show the power supply and antenna.

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