Category Archives: Radio history

1947 One Tube Broadcast Regen

1947AprPM1947AprPM2Seventy years ago this month, the father-son team shown here at the kitchen table couldn’t decide which of them was going to get the one-tube radio after they finished putting it together. But fortunately, the circuit was simple enough that they decided to simply make two of them, one for each. They are following the plans that appeared in the April 1947 issue of Popular Mechanics.

The set was billed as being for the beginner, and both easy to build and simple to operate. It used a single 6J5-GT tube as the regenerative detector, and could pull in standard broadcast stations with good headphone reception up to about 400 miles. To keep things simple, it used a transformer to supply the 6 volt filament current, but used a 45 volt battery to supply the B+.

1947AprPMchasisConstruction was made easy by the “semibreadboard” chassis shown here, consisting of two wooden slats mounted on two wooden strips. The two slats were spaced so that the tube socket could be mounted between them, eliminating the need to cut a large hole for the socket.

The magazine promised that the next month’s issue would show how to convert the set into a more powerful all band 4-tube set, although the one-tube design was more than adequate for the beginner who simply wanted to build a set to pull in local stations.


Amateur Radio Shut Down, 1917

QST, April 1917.

QST, April 1917.

With the declaration of war, Amateur Radio in the United States was shut down for the duration.  Both transmitting and receiving were banned, and amateurs were required to take down their antennas.

The official order was printed in QST, May 1917:

Office of Radio Inspectoor

To all Radio Experimenters,


By virtue of the authority given the President of the United States by an act of Congress, approved August 13, 1912, entitled “An Act to Regulate Radio Communication,” and of all other authority vested in him, and in pursuance of an order issued by the President of the United States, I hereby direct the immediate closing of all stations for radio communications, both transmitting and receiving, owned or operated by you. In order to fully carry this order into effect, I direct that the antennae and all aerial wires be immediately lowered to the ground, and that all radio apparatus both for transmitting and receiving be disconnected from both the antennae and ground circuits and that it otherwise be rendered inoperative both for transmitting and receiving any radio messages or signals, and that it so remain until this order is revoked. Immediate compliance with this order is insisted upon and will be strictly enforced. Please report on the enclosed blank your compliance with this order, a failure to return such blank promptly will lead to a rigid investigation.

Lieutenant, U.S. Navy,
District Communication Superintendent

1937 Popular Mechanics One Tube Shortwave Regen


Contrary to your initial impression, this is not an illustration of Junior helping Grandmother with her knitting. Instead, Grandmother is kindly obliging Junior in winding a coil for his new one tube radio. The radio builder is now almost a centenarian, since the illustration comes from the April 1937 issue of Popular Mechanics, which carried the plans for a simple one tube regenerative shortwave receiver.

1937AprPM2While the set was designed for the beginner, the circuit used a dual triode 6N7, and the inexpensive set demonstrated a “DX getting” ability equal to many sets with several tubes. It had a tight bandspread which made it an excellent performer in the crowded amateur bands as well as the 19 and 31 meter broadcast bands.

One half of the tube served as regenerative detector, with the other half serving as an audio amplifier to drive he headphones. In addition to the 6 volt filament supply, the set required a B+ of between 45 and 135 volts. While a battery eliminator could be used to run the set off household power, the article recommended use of batteries for best performance.

The chasis consisted of a wooden base, with an aluminum front panel. For tuning, one of the variable capacitors was set to the approximate frequency, with the smaller variable used to tune in the station’s exact frequency.

Coil winding instructions were included for four coils, covering the 160, 80, 40, and 20 meter bands. With all of those coils to wind, Grandmother’s help was almost certainly appreciated.

1937AprPMantAn antenna of 40 to 50 feet was recommended, and the illustration here shows Father helping to install it.  So that he can grow to become a centenarian, Junior is safely on terra firma while dad takes care of the climbing.


Clandestine English Receiver in Norway


The 1945 issue of Radio Missionary Log, the program guide for HCJB, Quito, Ecuador, carried this letter and photo which the station had received after the war. The writer, Kjell Gaarder of Norway, wrote that he had received HCJB on the receiver shown.

HCJB did not carry a Norwegian broadcast, but Mr. Gaarder listened to the station’s Swedish broadcast. He noted that there probably hadn’t been many reports from Norwegian listeners during the war, since the Nazis had seized all radio receivers in 1941, and prohibited listening on pain of death. But Mr. Gaarder reported that he “received, however, a small three-valve receiving set from England by parachute,” and had listened to HCJB with it.

According to the program guide, HCJB was broadcasting in Swedish ninety minutes per week, from 4:30-5:00 PM U.S. Eastern Standard Time (the same as local time in Quito) on Sunday, Tuesday, and Thursday. The broadcasts were on 12.5 MHz, the station’s main frequency, with 10,000 Watts. The Swedish broadcast would have also gone out with 1000 watts on 9.9 and 6.2 MHz.

Curiously, the book The Portable Radio in American Life mentions an RCA engineer named Kjell Gaarder, who made some adjustments to a small radio in 1940 to make it smaller.  It seems inconceivable that two small radios in different parts of the world just happened to have a connection to someone with the same unusual name.  It seems almost certain that the RCA engineer in America in 1940 was one and the same as the person who just happened to receive a radio delivered by parachute a few years later.

I suspect that Mr. Gaarder returned to Norway during the Nazi occupation, and probably participated in the resistance, as evidenced by his British radio.  There must be an interesting story here, and I hope some reader can give me some clues as to that story.

1932 Church Group Hearing Aid

Group hearing aid receiver in use.

Group hearing aid receiver in use.

Today, almost every auditorium of any description is wired for sound, and we take for granted that someone will turn on the PA, and we’ll be able to hear what’s going on through the ubiquitous speakers.

But this hasn’t always been the case. We take the presence of the sound system for granted. But until the early 20th century, there was an absolute prerequisite for orators of any type: They needed to have a loud voice in order to be heard.

This was particularly true of churches. There was one qualification for ministers that was even more important then their theological bona fides: They had to be loud, since their sermon had to fill the sanctuary on its own power, without the aid of any electrical amplification.

This began to change in the 1920’s and 1930’s, as the “sound man” became an important player in the field of electronics. Wiring halls of any type for sound became a lucrative profession. And with the advent of the microphone, amplifier, and loudspeaker, the sheer volume of the preacher’s voice became less and less of an issue.

A related issue was addressed by an article appearing 85 years ago this month in the March 1932 issue of Radio News. Electronic amplification could solve another problem, namely allowing those with poor hearing to fully participate in church services and other public events. Personal hearing aids worked well for conversation with another person nearby. But they were largely useless for picking up a speaker at the other end of a large auditorium. For that reason, churches and other public venues were beginning to wire what the article called “group hearing aids,” or what we would today call assistive listening devices.

1932MarRadioNewsSchematicAs seen from the schematic here, the circuit is quite straightforward. A microphone is placed near the pulpit, is amplified, and is then fed to telephone receivers with individual volume controls.

The article concluded by noting that the date was not far distant when those with defective hearing would be able to walk confidently into any hall or meeting place knowing that provision had been made for them to participate fully in one more phase of well-rounded living.

Modern assistive listening devices (ALD’s) are typically wireless, most frequently operating below the FM broadcast band at 72-76 MHz. You can read more about modern systems at my ALD receiver page.

World War II Radio Heroes: Letters of Compassion, by Lisa L. Spahr

We previously reviewed the book World War II Radio Heroes: Letters of Compassion by Lisa L. Spahr.  The book collects numerous letters from shortwave listeners to families of World War II POW’s held by the Germans and Japanese.  Names of prisoners were broadcast by Berlin and Tokyo radio, and these listeners contacted their families to reassure them that their loved ones were alive and well.

The Kindle edition is currently being offered at a sale price, and it’s well worth downloading this interesting book.  You can do so at the link below.

Canadian POW Sgt. Brian Hodkinson


Then 16 year old Hodgkinson at the CKY microphone, circa 1930. Manitoba Historical Society photo.

Then 16 year old Hodgkinson at the CKY microphone, circa 1930. Manitoba Historical Society photo.

This postcard from RCAF prisoner of war Sgt. Brian Hodkinson appeared 75 years ago this month in the March 1942 issue of CKY’s program guide, Manitoba Calling.  Prior to the war, Hodkinson was an announcer at the Winnipeg station.  With the outbreak of war, he enlisted in the air force, and on one of his first missions over France, he was shot down and held prisoner for the duration of the war.

This card was sent to a friend in WInnipeg, Dr. John Toole, and reports that the Germans were treating him well.  He requested “cigs. & chocolate, etc.” via the Canadian Red Cross.  Dr. Toole shared the card with the radio station.

Hodgkinson spoke little of the war years, but after much prodding by friends, he did put his memoirs on paper.  After the war, Hodgkinson moved to the United States and was for many years a newscaster and commentator at WHK, WERE, and WDOK in Cleveland.

After his death, a manuscript for a book was found.  It was published in Canada in 2000 as Spitfire Down.

The book is a fascinating look not only at Hodgkinson’s time as a POW, but also at his training.  The RCAF had to get pilots in the air as fast as possible, and the training was intense.  Hodgkinson recounts that he got lost on his first solo cross country flight, which was supposed to be from Ottawa to Kingston.  He got lost, and finally spotted an airport, which turned out to be Montreal.  Low on fuel and daylight, he landed and called his base for instructions.  After some discussion, he was told to return to Ottawa the next day.  He got lost again, and once again he landed at an unfamiliar airport.  When a friendly airport worker came out to meet the plane, he asked where he was, and was told that he had landed in Ogdenburg, New York.

Since the United States was still neutral, Hodgkinson realized that his navigation blunder would result in his spending the duration of the war in an American internment camp.  So he asked which way it was to Ottawa, and promptly flew north.

Despite these false starts, Hodgkinson was quickly sent to England, and on one of his first missions over France, he was shot down.  Most of the book recounts his experiences in a hospital in France, and then in prison camps in Germany.

One feature that stood out was the fluent English speakers that Hodgkinson encountered.  While he and his other prisoners in the hospital in France noted that before long they would be speaking a mixture of three languages, there were English speakers among his captors.  The first that he encountered was the doctor who oversaw the treatment of his injuries, Dr. Rudy Meinhoff.  Hodgkinson was surprised to hear the doctor address him with a clearly American accent.  It had turned out that the German doctor had practiced in Milwaukee before the war, and had even attended a medical conference in Winnipeg.

Hodgkinson (front row, center) along with fellow prisoners, 4 New Zealander and 1 English, 1944. Manitoba Calling, Apr. 1944.

Hodgkinson (front row, center) along with fellow prisoners, 4 New Zealander and 1 English. Manitoba Calling, Apr. 1944.

And upon his transfer to the German prison camp, Hodgkinson’s interrogator was Wehrmacht intelligence officer Col. Gustave Metterling, who also surprised Hodgkinson with an American accented English.  Before the war, Metterling had lived in New York, where he made a career of selling forged oil paintings, often made to order by wealthy buyers.

The book is not available in the United States, but used copies are available at a reasonable price on Amazon.  In Canada, it’s also available at

The book is a fascinating look at the war by one who had to sit most of it out.  According to Worldcat, relatively few libraries, American or Canadian, have a copy.  But it is apparently still in print from its Canadian publisher, and reasonably priced copies are available on Amazon.  It’s definitely worth seeking out.


Margaret Donahue, First Woman Licensed as Commercial Radio Operator

MargaretDonahue1917We previously wrote about Margaret Donahue of Boston, who was reportedly the first woman to receive her  first class commercial radio operator’s license.  This fact was reported a hundred years ago today in this clipping from the March 29, 1917, edition of the Bridgeport (CT) Evening Farmer.

She was at that time employed as a wire telegraph operator in Boston.  With her new credential, she had volunteered her service to her country in the upcoming war.


1952MarFMTVSixty five years ago this month, the March 1952 issue of FM-TV magazine carried this ad from the Radio Apparatus Corporation of Indianapolis, Indiana, for its monitor receivers, sold under the POLICALARM and MONITORADIO trademarks.  Five models were available.  For the 30-50 and 152-163 MHz FM public service bands, both 6 volt and 115 volt models were available.  For the AM aircraft band, a 115 volt model was available, covering 108-132 MHz.  All were continuously tunable.

The sets were marketed to police and public service agencies for two purposes.  First, “channel neighbors are monitored for pertinent information.”  In addition,  staff could have receivers in their homes or vehicles to be “constantly alert to communications while driving on or off duty, or at home.”

The ad even carried a testimonial from the city manager of Winchester, Virginia, who thought “you have a receiver that is well built, and I see no reason why it should not be in demand by all public works departments that have a transmitter available.”

There’s no indication that the City of Winchester actually bought one, but the city manager said he could see no reason why other cities wouldn’t want one. The ad did note that the receivers were in use by hundreds of municipalities “from Boston, Mass., to Alhambra, Cal.”

The 120 volt units appear to use the “POLICALARM” name, while the mobile units were “MONITORADIO.”  An example of one of the 120 volt units can be found at this eBay image.  A picture of the 120 volt Monitoradio AR-1 aircraft receiver can be found at The Radio Museum.  The set pictured is one of the 6 volt models, all of which had the same styling.  The units designed for household power resemble a broadcast receiver, with Bakelite cabinets.

Radio Apparatus Corporation later became part of Regency.

Preparing for the End of Civilian Radio Production


By orders of the War Production Board, manufacturing of civilian radio receivers ended on April 22, 1942, for the duration of the war. Even before this was announced on March 7, radio servicemen knew that at the very least, there would be shortages. When the ban was announced, they knew it was up to them to keep America’s radios in operation for their vital war information and for morale.

When the ban was announced, servicemen knew that it was time to double down, and they were reminded by advertisements such as this one, which appeared in the March 1942 issue of Service magazine.  The ad was from the John F. Rider company, publisher of service manuals.  These manuals contained diagrams and service information of virtually every set ever manufactured, and this data would prove invaluable for the radio servicemen tasked with keeping the nation’s radios in operation for the duration.