Monthly Archives: April 2022

1922 Crystal Set

1922SciInv1A hundred years ago this month, this receiver was the winner of first prize in a contest run by Science and Invention magazine, and appeared in the April 1922 issue. The set was said to be adequate for pulling in stations 15-20 miles away. The only tools required to construct it were a knife and small nail, it could be built in about 30 minutes, and the cost was only $30, including headphone and antenna. The phone receiver was the most expensive component at about $2, and the cost of the set itself was only 21-1/2 cents.

With a 25 foot antenna in New York, the set was said to pull in stations WDY and WJZ. In fact, the author reported that on several occasions, the phone could be held about six inches from the ear with music and voices clearly distinguishable.

The author, and winner of the $100 first prize was James Leo McLaughlin. You can see some more of his receivers at this link.


All of the parts are readily available, if you don’t have them around the house already. The chassis is a 4-inch diameter cardboard container. You can probably ask a friendly restaurant to give you one of their takeout containers, or you can use the time-honored crystal set chassis, namely, an oatmeal container.  The terminals are brass paper fasteners and paper clips.  You’ll need some 26 gauge enamel wire for the coil, and wire of any size for the antenna. In lieu of the headphone, it’s easiest to use a high-impedance crystal earphone.

Finally, the article calls for a piece of silicon or galena for the detector. The gift shops of most science museums have an assortment of minerals for sale, galena being one of them. Or, like everything else, you can order it from Amazon.

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1972 Grocery Prices

PghPress041672For a snapshot of grocery prices fifty years ago, this ad for Shop ‘n Save appeared in the Pittsburgh Press fifty years ago today, April 16, 1972. Of course, inflation took off shortly after these prices appeared. According to this online inflation calculator, one dollar in 1972 was the equivalent of $6.79 today, so the three pints of stawberries or 10 grapefruit for a dollar would be the same as $6.79.

The ham for $1.09 per pound works out to $7.40 per pound. Coffee was $1.89 for a three pound can, but that’s the same as $4.27 per pound in today’s money.

What do you think are the biggest bargains on this page?  (Click on the ad above for a full size image.)



Texas City Disaster: 1947

Parking lot a quarter mile from the blast. Wikipedia photo.

Saturday marks the 75th anniversary of the deadliest industrial accident in U.S. history, the Texas City disaster of April 16, 1947, which started as a fire aboard the French-registered vessel SS Grandcamp docked at Texas City, Texas, with 2200 tons of ammonium nitrate. The disaster killed at least 581 people, including all but one member of the Texas City fire department.

Smoke was spotted in the cargo hold of the Grandcamp at about 8:00 AM. The captain ordered his crew to steam the hold, which probably made matters worse by converting the ammonium nitrate to nitrous oxide.

Spectators gathered, believing that they were a safe distance away. The sealed hold began to bulge, and water splashing against the hull began to boil.

The cargo detonated at 9:12 AM, with a blast leveling over a thousand buildings on land and destroyed the Monsanto chemical plan and ignited refinery and chemical tanks on the waterfront. Bails of twine from the cargo were set afire and hurled around the city. People in Galveston, 10 miles away, were forced to their knees, and the shock wave was felt as far as 250 miles away.

The ironically named SS High Flyer was docked nearby, and the blast set fire to that ship’s cargo of ammounium nitrate. Fifteen hours later, that ship exploded.

Hams Take To The Air

As might be expected, the blast destroyed much of the city’s communication infrastructure, and amateur radio operators quickly responded to fill the gap.  Many of these stories are detailed in the July 1947 issue of QST (pages 38-40).

B.H. Standley, W5FQQ, on the air at city hall, along with city clerk Ernest Smith, Nurse Mrs. E.L. Brockman.

B.H. Standley, W5FQQ, on the air at city hall, along with city clerk Ernest Smith, Nurse Mrs. E.L. Brockman.

By noon, the first amateur portable and mobile stations had moved into the city and were on the air, working in conjuction with Army, Navy, Coast Guard, U.S. Engineers, FBI, and local and state police. Links were quickly set up between City Hall and stations in Houston and San Antonio. Most traffic was handled on 75 meter phone and 80 and 40 meter CW. W5KMZ reportedly handled over 200 messages, mostly involving needed medical supplies. As the hours went on, additional traffic was handled by W5FQQ at the mayor’s office, with over 300 messages passing on behalf of city officials, the Army, Red Cross, and Salvation Army.

An impromptu three-way net was established on 3989 kHz between Texas City, Galveston, and Houston.  The FCC issued an order clearing the frequencies between 3840-3860 kHz, as well as 7050 for emergency use.

Two hams, W5FQQ and W5EEX, had been advised to evacuate but remained at their stations. They narrowly escaped death when the High Flyer lived up to its name with its explosion. W5FQQ was on the air at the time of the blast, and the blast was heard by W5IGS in Houston. 21 seconds later, the Houston station experienced his windows shaking.

W1AW declared the emergency to be over 11 days later, on April 17.

Broadcasters Cover the Disaster

Broadcasters also did their part to provide emergency relief.  The FCC allowed broadcast stations to carry personal messages, ordinarily not permitted by the rules.  According to the April 21, 1947, issue of BroadcastingKPRC, the Houston NBC affiliate, was the first to announce the explosion of the French ship. A mobile crew was rushed to Texas City, and the station was able to feed live descriptions of the tragedy. It also broadcasts lists of wounded at hospitals in Galveston, Houston, and other nearby towns.

Another Houston station, KTHT, similarly acted in the public interest. The Texas Highway Patrol used the station as an unofficial traffic control outlet, warning away sightseers and directing public service vehicles. The station was on the air on a 24 hour basis, and no commercials were aired for two days. In fact, when the High Flyer exploded, the sound was carried live over the station’s report.

KXYZ and KTRH in Houston, as well as KRLD Dallas broadcast emergency information.

In Galveston, KGBC aired the first bulletin minutes after the first explosion, and aired 24 remote broadcasts. Normally a daytime station, it was granted authority to broadcast 24 hours.

KLUF in Galveston also remained on the air on a 24 hour basis, with emergency messages given priority. Long lists of the dead, missing, and injured were also aired.

KPAC in Port Arthur, a station we’ve previously featured, also carried emergency announcements and instructions from police and other officials. Another Port Arther station, KOLE, chartered a plane to get newsmen to the scene.

In San Antonio, WOAI received a request from the NBC network to charger a plane, fly over the area, and report back in a broadcast from San Antonio. Their description was aired on the network broadcast that evening.

Litigation Ensues

As might be expected, considerable litigation followed, much of it under the Federal Tort Claims Act for alleged negligence of the U.S. Government. The case ultimately made its way to the U.S. Supreme Court, Dahelite v. United States, 346 U.S. 15 (1953), in which the court held that the Government was not liable, since all of the claimed government negligence amounted to discretionary acts.



1947 Two-Tube Transmitter for 80 and 40

1947AprRadioNews4From the April 1947 issue of Radio News, this three-piece unit is a simple transmitter for 80 or 40 meters. The transmitter itself is the center chassis, using two tubes to put out 10-30 watts with a crystal-controlled oscillator and one stage of amplification. It will load up into a longwire, a tin roof, or just about anything that’s available. The main advantage of the additional RF stage is to keep the antenna from loading down the oscillator, and the author notes that the RF stage is untuned, so you don’t have to worry about it breaking into oscillation.

If desired, the modulator stage will turn the set into a ‘phone rig, but for the CW man, this can be dispensed with.

The author, Byron Lindsey, Jr., W4BIW, an engineer at WSB, reported that the transmitter could be put together on a single rainy day, and that a similar design had been use at his station for ten years.

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1962 One Tube Radio

1962SpringRadioTVExp3Some of our readers are beginners, but we have no doubt that they are serious beginners. Therefore, we are sure that this one-tube broadcast receiver from 1962 will be of interest. The chassis is made of plywood, and empploys a singe 6SN7 tube. Half of the tube serves as a regenerative detector, with the other half amplifying the audio. A “dry” rectifier is used in the power supply, although a semiconductor diode could just as easily be substituted. The chassis was made of plywood, handsomely stained, and the result was an effective personal or bedside receiver, sure to provide the maker with many pleasant experiences. The project appeared in the Spring 1962 issue of Radio-TV Experimenter.



Science Fair Idea: Lens Made of Air

1937AprPS1For the student looking for a simple science fair project that will mystify the teacher, you’ve come to the right place. When the teacher asks what scientific question(s) your project will demonstrate, you can propose the following:

Is it possible to construct a convex lens that will have a magnification factor of less than one? Is it possible to construct a concave lens that will have a magnification factor of more than one?

ConvexConcaveTo put it another way, a convex lens (such as the one on the left) makes things look bigger, and a concave lens (shown on the right) makes things look smaller. But your simple experiment will show that it’s possible to make a convex lens that makes things look smaller, and a concave lens that makes them look smaller.

A lens is usually made out of a substance such as glass, which is denser than air. This means that light waves travel more slowly through the lens. But there’s no reason why you have to use glass and air. In your case, you will use air for the lens, and water instead of the air. This means that the speed of light is faster through the lens, rather than slower, as we usually think of lenses.

The layout for the lens is quite simple, as you can see from the illustrations. You need a small1937AprPS3 can, covered on each side with a piece of cellophane. Any type of clear flexible plastic should work fine. The easiest option is probably cling wrap. You’ll need to cut a hole in the side of the can, and insert a flexible rubber or plastic tube. The connection needs to be air tight. There are probably other ways to make the connection, but the easiest would probably be to use a small brass tube, and solder it to the can.  (You’ll need a soldering iron, which probably costs a lot less than you would expect.)  Slide the plastic tube over the brass, and make sure the connection is water tight.  The construction details are shown at the right.

1937AprPS2If you blow into the tube, as shown in the illustration above, then the can becomes a convex lens, made out of air. And if you suck air out of the tube, as shown at the left, it becomes a concave lens. Place it in a container of water, and you can watch how a black stripe at the bottom of the container is magnified or made smaller, but the opposite of how it would work with a glass lens in air.

Your teacher will have to concede that there’s nothing in the definition of “lens” that requires it to be made out of glass. He or she will have little choice but to award you the blue ribbon for answering your questions in the affirmative.

The project appeared 85 years ago this month in the April 1937 issue of Popular Science.



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1947 Phono Maintenance Tips

1947AprPMrecord1947AprPMrecord2This young woman enjoyed listening to her record player, but thanks to the hints in the April 1947 issue of Popular Mechanics, she also knew how to take care of it. The record player was designed to withstand rough handling, but it was also a precision instrument that required occasional attention.

For one thing, the wires under the pickup arm could come loose and drag along the record. The magazine explained how to pull the wires tight to prevent this.

If the record player wouldn’t play at all, it was likely the cartridge, and the magazine explained how to replace it. It also explained the importance of cleaning dust off records, as well as the need to occasionally oil the bearings.



Eclipse of April 8, 2024

2024 Eclipse Path. NOAA image.

2024 Eclipse Path. NOAA image.

As we did in 2017, OneTubeRadio.com will provide full coverage of the April 8, 2024, total solar eclipse, which will take place two years from today.

For the 2017 eclipse, hotel rooms and other accommodations started becoming scarce a few months prior to the eclipse.  A few rooms remained available up until two weeks prior to the eclipse.

In general, most hotels allow you to make reservations one year in advance.  Therefore, if you plan to see the eclipse in an area experiencing totality, which we strongly recommend, then you should plan on booking a hotel room on April 8, 2023.  For the 2017 eclipse, we booked a fully refundable hotel room, so there was no risk if we changed our plans.  In 2024, we’ll probably view the eclipse in Texas, although our plans are not settled.  For the 2019 annular eclipse, we had contingency plans that included both a hotel and campground in Canada, and a campground in the U.S.  Since the border was still closed, we cancelled the Canadian reservations, since we made sure to get fully refundable ones.

Speaking of annular eclipses, there is one of those on October 14, 2023.  That event, while interesting, is nowhere near as breathtaking as a total eclipse.  So if you happen to be close, you should take in the 2023 event.  But the 2024 total eclipse is in an entirely different league.

The 2024 total eclipse will be visible in parts of Texas, Oklahoma, Arkansas, Missouri, Illinois, Indiana, Ohio, a tiny piece of Michigan, Pennsylvania, New York, Vermont, New Hampshire, and Maine.  The path of totality also passes through Mexico and Canada.  Major cities in the path of totality include Dallas, Little Rock, Indianapolis, Buffalo, Cleveland, and Montreal.

Please don’t be confused when you hear about “percentages” of eclipse.  Some people are lulled into believing that since they will experience a “90% eclipse” at their home, or even a “99% eclipse,” that there is no need to travel.  This is a big mistake.  Even with a 99% eclipse, the experience is completely different from a total eclipse.  Unless you are paying attention, you might not even notice the 99% eclipse.  But you’ll definitely notice the total eclipse just a few miles away, since it will become noticeably dark outside.

Also, in late 2023 or early 2024, you should order your eclipse glasses.

If you have kids who will be in school, plan on taking them out of school that day.  Unfortunately, the 2017 eclipse showed that American schools had an irrational fear of the eclipse and actively prevented children from witnessing it.  If you believe that your child’s school is more enlightened, then on the first day of the 2023-24 school year, you should have your children ask the science teacher if the school is planning a field trip to see it.  If the teacher balks, then your children should let him or her know that they will be absent the day of the eclipse.

This is an entirely reasonable request for most schools.  For example, students in Chicago could be placed on a school bus and taken to see the eclipse only a couple of hours’ drive away in Indiana.  The expense will be less than other field trips taken to amusement parks, movies, etc.  This is true for schools in many cities.  They have the opportunity to let the kids witness an amazing scientific event, but only if they do some basic planning.

But I predict that this won’t happen, since most schools won’t think of the possibility until after it’s too late to make the necessary plans, or they’ll have the same irrational fears that showed up in 2017.  It’s the duty of the students to pester the administration so that the necessary plans are made sufficiently in advance.  And as I explained in 2017, if the school fails to act, then it’s reasonable for children to skip school on April 8, 2024.

 

 



Don Leary’s Record Store, Minneapolis, 1947

1947AprRadioRetShown here from 75 years ago are some views of Don Leary’s record store in Minneapolis. These images appeared originally in an issue of the store’s 12-page Don Leary Record News, which went out to over 25,000 people every month.  The image was reprinted in the April 1947 issue of Radio Retailing., and that magazine highlighted the store’s ongoing advertising campaign, and the monthly newspaper was a key part of that advertising. The emphasis was on records bulletins and lists, but also highlighted the other aspects of the store’s business, namely, radio, appliances, and service.

The store had over a quarter million records in stock, and its business philosophy was that the logical place to buy a radio or phonograph was where you bought your records. It was good business, since the satisfied customer would keep coming back for records.

In addition to its own newspaper, Leary reported that the store was the largest user of newspaper advertising space of any record store in the region. He also made a point of having friendly relations with reporters, who came to quote him as the expert in all things involving records. For example, he had recently been quoted in the Minneapolis Star-Journal regarding juke boxes, which he viewed as a good thing for the welfare of city youngsters. (Incidentally, it was an industry in which he was also involved.)

More biographical information about Don Leary can be found at this link.  The store was opened in 1941 at 56 East Hennepin Avenue, on Nicollet Island. That address doesn’t really exist any more, but would be at the spot indicated on the Google Maps image below:

NicolletIsland

Nicollet Island, 2022 (Google maps) and 1940

The aerial view at the right was taken in 1940, and shows a business district along East Hennepin, the street connected to the mainland by the two bridges. Over the years, East Hennepin was paired up with First Avenue Northeast as complementary one-way streets. On the island, they form a short four-land divided road, and there are no lots directly adjoining it. To the North, there is now a view of De La Salle High School, and to the South, there is now a view of the Nicollet Island Inn, both of which would have been obscured by buildings on East Hennepin in the 1940’s.  Leary’s store would have been one of the buildings on the South side of the street, probably the fourth one from the left.

I write about a lot of people on this site, and I think this is the first time I’ve written about someone who I personally met back in the day. I believe East Hennepin got its current configuration through the island in the early 1970’s, and Don Leary’s was long gone by the time I remember being there. However, from 1971 through 1979, he owned a record store in a small suburban strip mall at 2927 NE Pentagon Drive, St. Anthony, MN.

Despite the small size of that store, he probably still had a quarter of a million records in stock, of all genres. I was looking for something by Jimmie Rodgers, the Singing Brakeman (1897-1933).  I asked Leary, who seemed to run the store as a one-man operation whether he had anything, and he asked me whether I actually meant the unrelated Jimmie F. Rogers, who was born the year the elder Rodgers died. When I let him know that it was the Singing Brakeman I was after, he commented something to the effect that he went way back, but showed me an assortment of his records.

Leary died in 2000 at the age of 92.



End of Civilian Radio Production: 1942

1942AprRadioRetAs we’ve previously reported, civilian radio production in the United States ended for the duration of the war on April 22, 1942.  The graph above, which appeared on the cover of the April 1942 issue of Radio Retailing, showed how critical the radio repairman would be to keep the nation informed.  As of that date, there were 57 million radios in American homes.  In the years prior to the war, about 10 million new sets were made each year, but about 5 million old sets were scrapped by their owners each year, for a net increase of about 5 million.

With the end of production, the supply would remain at 57 million for the duration–but only if every radio was kept in service.  If the prewar trend of 5 million radios per year being scrapped continued, then the number would be as shown in the graph at the right.  And if repair parts became unavailable, then the situation would be even worse.  The supply of radios would plummet, as shown by the steeply declining graph.

The message was clear:  To keep the American public informed, dealers would need to concentrate their efforts on repairs, and manufacturers and the government would need to make sure that repair parts remained available.