Category Archives: Radio history

1957 Boys’ Life Telephone Circuit

1957NovBL1Sixty years ago, Maurice Peacock, Jr., of Radnor, PA, got $5 for sending these simple circuits to the “Hobby Hows” editor of Boys’ Life, where they were printed in the November 1957 issue.

The circuit shows how to rig up a telephone system to a friend’s house nearby, using an old radio headphone. One earpiece is used at each end, with batteries wired in series. Peacock explains that the wire needs to be insulated, and suggests that old thread spools can be used as insulators. The basic circuit is shown in figure 1. To save on the cost of wire, a good ground can be used as the return, as shown in figure 2.

I suspect the Boy Scouts of 1957 eventually figured it out, but the diagrams shown here wouldn’t work. A minor change needs to be made.

I suspect that, just like the Boy Scouts of 1957, our readers will quickly spot the problem. When you’ve found it, please comment on our Facebook page.



1942 Army Signal Corps Recruiting

1942NovPMThis recruiting ad for the U.S. Army Signal Corps appeared in Popular Mechanics 75 years ago this month, November 1942. It noted that this was a radio war, and that the nerve center of the army needed skilled hands.  It suggested a number of opportunities to serve.

Physically fit men ages 18 to 45 were eligible for direct enlistment in the Signal Corps Enlisted Reserve.  Those with experience as a licensed radio operator, a trained repairman, or active telephone or telegraph worker would qualify for active duty at once with pay of up to $138 per month, plus board, shelter, and uniforms.

Those without direct experience but “skilled with tools” would qualify for training and ordered to active duty after completing the course.

Degreed electrical engineers, as well as junior and seniors in EE programs, would be eligible for commission.

Young men over 16 having an ability with tools would be eligible for immediate training, with pay of not less than $1020 per year.  Even those with a minor physical handicap could find a place to serve.



Billy Hallicrafters to the Rescue Again

1957NovBLA few months ago, we reported how young Billy Hallicrafters used his Hallicrafters shortwave receiver to save the lives of some men aboard a sinking ship.

Here, we see young Billy at it again, saving the life of a pilot in distress, as reported in the November 1957 issue of Boys’ Life.

Billy was apparently late for school that day, but I’m sure his tardiness was excused.  We enter the story as Billy’s mother reminds him that it’s time to get ready for school.  He prepares to shut down his receiver and get to school, but at the last minute, he hears something truly ominous.

He hears a pilot, apparently in communication with air traffic control, since the pilot is acknowledging a message. But the pilot interrupts the acknowledgment to declare a mayday, which apparently only Billy hears. The pilot had “flamed out 10 miles south of Westport” and was bailing out.

Billy interrupts his school preparations and frantically calls the Civil Air Patrol to report the emergency. Within minutes, a CAP helicopter is dispatched, and spots the parachute. One of the crew comments that it’s a good thing that boy was tuned in, since nobody else heard the Mayday.

The crew quickly gets the unconscious pilot out of the tree where he’s dangling and to the hospital. In the next scene, Billy is visiting the hospital where the downed pilot thanks Billy for saving his life.



Hammarlund Super Pro Console, 1937

1937NovRadioWorld

The Hammarlund Super-Pro series of receivers represent one of the best performing prewar communications receivers. The line was first introduced in 1936, and when war came, they took the BC-779 nameplate for the military version.

Thousands of the models making up the series rolled off the Hammarlund assembly line over the years, but one of the rarest variations is shown here, and it appears that only about 70 were made.  Inspired, no doubt, by high-end home consoles such as the McMurdo Silver, Hammarlund decided to move the set from the ham shack to the living room.  So they put it in the cabinet shown here, as seen in the August 1937 issue of Radio World.

But it wasn’t just any cabinet that they slapped it into.  As the accompanying article explains, the cabinet was carefully designed for its audio qualities, particularly the bass response.  There’s no doubt that the set was a top performer, and I’m sure it sounded good.  Since it was destined for the living room, a few modifications were made.  For example, even though the set had a BFO for listening to code, the BFO pitch was not adjustable from the front panel.

But it was a flop as far as sales.  As the Radio Boulevard site explains, “it just wouldn’t do for hams – it had no BFO on the front and it was too big. It didn’t have the Scott or McMurdo chrome chassis – how could you impress your friends?”  The site does have a picture of a nicely restored specimen, owned by AA6S.  From the color picture, it does look like a communications receiver thinly disguised as a console.  The front panel is faux walnut, and just looks out of place.  It’s not quite a communications receiver, and it’s not quite a console.

I’d love to have one in my living room.  And as a loyal reader, you would love to have one.  But let’s face it, nobody else would want one!



Elizabeth Rickard, Radio Pioneer

1917NovElecExpShown here, from the November 1917 issue of Electrical Experimenter,
is Miss Elizabeth Rickard, the first woman to graduate as a radio operator from Hunter College, New York City. According to the magazine, she received her first grade commercial license.

The school had a “very enthusiastic wireless class who are blest with every provision for quickly assimilating the intricacies of radio telegraphy.” The Marconi company had presented the college with standard receiving and transmitting equipment, as well as instructors.

Miss Rickard entered the college’s wireless class in April 1917, and in May of that year, she was detailed to the Marconi school for intensive training. She passed her tests in July, with the highest scores of the class of 20 men and 3 women.



1937 Montgomery Ward Ham Station

1937NovRadioNews

Eighty years ago, the October  and November issues of Radio News carried a review of the model OR-5 transmitter for the 160 through 10 meter bands put out by an unlikely supplier for ham gear, namely Montgomery Ward & Company.

The reviewer, Everett Walker (whose call was, coincidentally, W2MW, whose 5 meter station we previously featured), posted an overall favorable review of the transmitter: “the small transmitter proved itself an excellent all-band unit on small power. On the higher frequencies it proved a good competitor for the 500 watt transmitter used at W2MW. On the lower-frequency bands it put out a signal that could compete with the normal QRM with more effectiveness than was expected. The transmitter also was tested on 160 meters, not at the writer’s station, but at a nearby station that was equipped with an adequate antenna. Here it put out a good signal and the operator who made the test reported local communication was excellent and more than six “out-of-the-district” stations were worked within a short time.”

He noted that the rig put out 60 watts CW on all bands but 10 meters, where it put out 40 watts.

The rig was geared mostly for the CW man, but the accompanying OR-7 modulator was also available for AM use. In the photo above, the transmitter is at the right, with the modulator in the middle. The accompanying receiver on the left, whose model number is not stated, is also from Montgomery Ward.



1937 Little Giant Cathedral Crystal Set

1937LittleGiant

This ad for a “Cathedral” radio from the Little Giant Radio Company of 1166 Diversey Pky, Chicago appeared in Radio Guide 80 years ago today, November 20, 1937.

The ad praises the set in near miraculous terms, and contains a number of glowing endorsements. Of course, the set is a simple crystal set. The “cabinet”, it turns out, is made of cardboard, and the earphone is mounted permanently right on the back. So to listen, you have to hold the whole radio up to your head.  The set had two large alligator clips, presumably to attach to an antenna and ground.  But it’s just $2.95, they would send it C.O.D., and your satisfaction was guaranteed.

More informaton, and a picture of the set, can be found in Volume 2 of Crystal Clear: Vintage American Crystal Sets, Crystal Detectors, and Crystals.  (Volume 1 and Volume 2 of that set are both available on Amazon.) You can also see some more photos of the set at this link.



US Army Signal Corps, 1942

Signal Corps mobile radio unit.

Signal Corps mobile radio unit.

Seventy-five years ago this month, most of the November 1942 issue of Radio News was devoted to the U.S. Army Signal Corps, and included dozens of photographs, including the color photos shown here. The photos themselves were taken by Signal Corps photographers, which comprised a branch of the service.

Here are a few of them, showing various phases of both wireline and radio communications.

Command car equipped for both voice and code communication.

Command car equipped for both voice and code communication.

Operation of handheld radio from Jeep, probably around 50 MHz.

Operation of handheld radio from Jeep, probably around 50 MHz.

Radio-equipped halftrack.

Radio-equipped halftrack.

Students receiving instruction on portable transmitter.  Note operating frequencies of ___ kHz.

Students receiving instruction on portable transmitter. Note operating frequencies of 2300, 2900, and 3400 kHz.

Operating radio from concealed position with hand-driven generator.

Operating radio from concealed position with hand-driven generator.

Operating four-band portable field set.

Operating four-band portable field set.

Field telephone in operation.

Field telephone in operation.

Field telephone switchboard.

Field telephone switchboard.

Placing telephone lines.

Placing telephone lines.

 

 

 



1933 One-Tube “Triflex” Shortwave Receiver

1933NovSWAs our loyal readers are aware, we often get off on tangents here at OneTubeRadio.com, but we always try to get back on track by showing actual One Tube Radios.  And the one we offer today has all the hallmarks of being an excellent performer, covering the range of 10-200 meters.

1933NovSW2This is a one tube radio, since it uses a single 6F7.  But we’re cheating a little bit, not only because it’s a dual tube, but because the two halves of the tube are actually doing the work of three tubes.  The 6F7, which is still readily available at a reasonable price, consists of a pentode and a triode in the same envelope.  In this circuit, the pentode is used as an RF amplifier, with the triode serving as the regenerative detector.  But through the magic of “reflexing,” the pentode is then used a second time to serve as an audio amplifier.  The result is that the set gives the performance of three tubes, while only using a single tube.

The circuit originally appeared in the November 1933 issue of Shortwave magazine, in an article written by “well known shortwave engineer” Clifford E. Denton, who dubbed the set the “Triflex.”

For those wishing to duplicate the circuit, parts, or reasonable substitutes, should be readily available.  The new-old-stock tube can be found at this link.  You’ll probably need to make the plug-in coils yourself, but you’ll find helpful hints at this post.  Most of the other parts can be tracked down at my parts page.

1933NovSWschematic



1942 RCA Shortwave Transmitters

1942Nov16BCSeventy-five years ago today, the November 16, 1942, issue of Broadcasting carried this ad with a story showing the importance of the nation’s shortwave broadcast transmitters.

When Herr Braun was ordered to report for farm work in the south of Germany, he made an arrangement with his brother who worked in the rail yards. No matter what happened, the brother promised to write from Cologne every week.

At first, Herr Braun received letters written on cheap thin paper. But one week, the letters stopped with no explanation. The local Nazi paper reported an ineffective British raid on Cologne, but with only small damage. The Luftwaffe was invincible, according to the paper, an the enemy could never reach Cologne in force.

But the letters never came. So one night, Herr Braun tuned to a forbidden station–an American shortwave station. “And there it was–the facts, the figures, the full grim story of the mighty German city blown to bits from the air. Yes, the railroad yards were destroyed.”

So Herr Braun started to wonder. The newspaper had lied. Thanks to the powerful shortwave transmitters using RCA equipment, Herr Braun’s faith began to fade.