If you need to liven up Junior’s next party, you can put together this circuit for a fun game of “hunt the bleeper,” as described in the November 1972 issue of Practical Wireless.

The magazine noted that British children love noise, and this is equally true on this side of the Atlantic. The beeper, which draws only 600 microamps, puts out a high pitched tone at a low level. The device was to be hidden, and the children would be split into two teams to find it. There were two strategies available: They could concentrate on finding the device, or they could make so much noise to keep the other side from hearing it.

The cost was said to be 50 pence, which didn’t include the case, which was one of the then-ubiquitous 35mm film can, which was deemed to be free. Even though they’re no longer free, like everything else, you can find them on Amazon.

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Seventy-five years ago, this microwave relay station was under construction atop Jackie Jones Mountain near Haverstraw, NY. It was one of seven microwave relay stations linking Boston and New York, delivering television programs with a 1 watt signal on 4000 MHz.

It is pictured here on the cover of the November 1947 issue or Radio News.

More than once, I’ve seen a meme extolling the virtues of a product similar to the one shown here. The accompanying text is usually along the lines of:

In Japan, a sink is built above the toilet tank for hand washing. The water drains into the toilet tank to be used for the next flush, and saves millions of gallons of water each year.

This is usually followed by many gushing comments stating what a great idea it is.  Along the way, it usually turns into a discussion of how stubborn Americans refuse to adopt this idea, or that a conspiracy by the Big Toilet Companies has suppressed the idea. Invariably, when I point out the disadvantages, everyone wants to argue with me, although nobody actually wants to buy one, even though they are readily available.

It’s actually not a bad idea, and there are certain niche applications where it could really come in handy. For example, if you wanted to install a toilet in a room that simply did not have room for a sink, it would be a good choice.

The people who take a strong position about what a good idea this is often don’t seem to understand exactly how it works, and their comments often reflect their confusion. When you flush a toilet, the water to flush is expelled from the tank, and runs through various pathways in the porcelain and into the bowl. Simultaneously, the tank starts refilling with water for the next flush. This product runs that refill water through a faucet on top, through a drain, and into the tank. So in the minute or so that the tank needs to refill, the little faucet on top of the toilet is running. It uses the same amount of water as any other flush. But since it’s now running outside the tank, if you want, you can wash your hands with it. Again, this is an excellent idea, and probably has some niche applications.

But there are a few problems, and depending on your solution to these problems, you might cause more environmental problems of the type you were hoping to solve.

First of all, in most parts of the country (other than areas with very high humidity), you flush the toilet with cold water. But most people wash their hands with hot water. There are two solutions to this problem. Interestingly, one viable solution is to simply resign yourself to the use of cold water. The CDC in its wisdom, for example, provides handwashing instructions calling on you to “wet your hands with clean, running water (warm or cold)” before applying soap.

However, most Americans probably prefer the familiar warm water when washing hands. So the other alternative is to connect the toilet to the warm water, instead of the cold. But this means that every time the toilet gets flushed, you are heating up 2.5 gallons of water, whether or not you wash your hands. And even if you wash your hands every single time, you use much less than 2.5 gallons in the process. So the net effect is that by making this change, you are unnecessarily heating up a lot of water, which you will literally flush down the toilet. That doesn’t sound like a very “green” thing to do.

Another potential problem is buildup of dirt or soap scum in the rim jets of the toilet. When you flush the toilet, water goes through various pathways in the porcelain, and into the bowl. Some of these, particularly the rim jets at the top of the bowl, are rather small. They are designed to have clean water run through them, and it seems to me that if you run grey water through them, there’s a potential for them to get clogged up.  (And of course, if anything else ever gets poured down the drain, it runs the risk of clogging those little openings.)

It is possible to clean the jets, at least to some extent, by getting down on your hands and knees in front of the bowl, and reaching in with a small brush. But since most of the water’s path is buried in the porcelain, it seems to me that there’s a potential for clogging in an inaccessible area. Of course, you can probably clean them by pouring in toxic chemicals, but if the whole point of this exercise was to “go green,” that doesn’t seem like a good alternative. And if you have to eventually replace the toilet, sending the old one off to the landfill doesn’t sound like a particularly environmentally sound thing to do.

Another issue is washing your hands other than after using the toilet. The only way to get the water to flow is by flushing the toilet. So whenever you want to wash your hands for any reason, you must either find another sink, or else send 2.5 gallons of water literally down the drain. Also, if you are in the middle of washing your hands, but you didn’t quite finish rinsing, you have no choice but to send another 2.5 gallons of perfectly good water into the septic system.

The final issue is that the tank isn’t located very conveniently for washing your hands.

Despite these issues, this is actually a rather good idea, as long as you understand these limitations. If you can live with these downsides, you’ll be glad to know that the Big Toilet Companies are not suppressing this invention. Indeed, like anything else, you can get them at Amazon, at the links below.

The one in the center appears to be the one that shows up most frequently in the meme. Even though the meme claims that it’s from Japan, the product is actually proudly made in the USA, from what appears to be durable plastic. The one at the right is similar, but for slightly larger toilet tanks. So measure carefully before ordering. When your new sink arrives, it looks like a very easy installation, and you can send the old lid off to the landfill as you celebrate your new green innovation.

The model shown at the left below is the deluxe version, and includes both the tank and the lid. Unlike its plastic brethren, this one is made of the same ceramic as the rest of the toilet fixture, and will probably last centuries in normal use, although installation is more involved.

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Sixty 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.

If 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.

Eighty 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.

Here’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.

Image courtesy of Gerald Ford Presidential Library Facebook page.

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.

Sixty 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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