Category Archives: Radio history

Last Prewar Radio

Today marks the 80th anniversary of the end of civilian radio production in the U.S. for the duration of World War II, and shown here is the last radio to roll off the RCA assembly line before the company switched over exclusively to defense production.

RCA was actually ahead of schedule, and this radio-phono was manufactured in Camden, N.J., on April 7, 1942. The chassis had been completed on March 5.

This last set was donated to the Georgia Warm Springs Foundation, where it would uplift the spirits and morale of the young patients there.

The picture appeared in the May 1942 issue of Radio Retailing.

1947 One-Tube Regen

The plans for this handsome little one-tube receiver appeared 75 years ago this month in the April 1947 issue of Radio News.

The magazine noted that this simple circuit was one of the most useful pieces of equipment you can build. Obviously, it could be used as an extra receiver, but could also be put to other uses as well.

One half of the 1G6-GT tube served as regenerative detector, with the other half serving as audio amplifier to drive a pair of magnetic headphones. (The article points out that crystal earphones wouldn’t work with this circuit.) It is mounted on a 5 by 7 inch plywood base, with a front panel made of sheet steel. With four plug-in coils, the set would tune from below the broadcast band up to 18 MHz.

1922 Crystal Set

A 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.

Some links on this site are affiliate links, meaning this site earns a small commission if you make a purchase after clicking the link.

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.

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 Broadcasting, KPRC, 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

From 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.

1962 One Tube Radio

Some 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.

Don Leary’s Record Store, Minneapolis, 1947

Shown 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:

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

As 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.

1962 One Tube/One Transistor Broadcast Set

Sixty years ago this month, the April 1962 issue of Popular Electronics carried the plans for this hybrid one-tube/one-transistor receiver for the broadcast band. According to the magazine, the set would provide room-level volume on local broadcast stations, and while not hi-fi, was more listenable than one would expect from such a simple circuit.

The detector used a 12AE6-A tube as grid-leak detector. Since the tube was intended for hybrid car radios, it could run on a very low B+ voltage. In this case, that was 12 volts supplied by a filament transformer. The audio amplification was handled by a 2N231 germanium PNP transistor. The final semiconductor component was a 1N34 diode serving as rectifier.

The tuning coil was wound honeycomb style on a cardboard form. The set was said to pull in the local stations with an 8 foot antenna tucked behind a bookcase.

Prismatone Organ: 1947

This musician is playing the Prismatone electronic organ, what the April 1947 issue of Radio Craft asserted “promises to be by far the most attractive of all the lower-priced electronic music instruments.” The musician here was highly skilled, as the magazine noted that the instrument required a skilled operator.

The instrument consisted of a projector sending a beam of light through a translucent disc, which projected a rapidly altering pattern. The colors are solely for the benefit of the operator, as the instrument instead depended on the frequency of the pulsating light beam caused by the disc. The two wands contain photocells, and their output is the same frequency as the portion of the light at which they are aimed. Volume can be changed by altering the angle at which each wand was held. The outputs were fed into a high-fidelity audio amplifier.

The magazine noted that for an even more spectacular effect, the musician can wear finger rings with small selenium photocells in lieu of the wands.

The instrument was created by one Mr. Leslie Gould, a “well known Connecticut inventor of many electronic devices,” including “the Sonicator, a radar-like instrument for small boats.” One of Gould’s earlier inventions, part of a tuning mechanism, was at issue in Levy v. Gould, 87 F.2d 524 (C.C.P.A. 1937).

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