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1956 Solar Radio

1956RadioElectr

Sixty years ago this month, the March 1956 issue of Radio-Electronics published the plans for this solar powered radio, probably the first instance of a project using a photovoltaic cell for power.

The actual radio receiver was a simple crystal set, using a germanium diode, with a single CK-721 transistor serving as the audio amplifier.  The basic circuit was about the same as the Boys’ Life CONELRAD receiver shown here previously, which appeared the same year.

The power came from a type B-15 self-generating selenium photocell, manufactured by International Rectifier. The cell didn’t put out the required 1.5 volts, so it was necessary to cut it into four pieces with a hacksaw, and then wire the resulting four smaller cells in series.

For times when the sun wasn’t shining, the plans also called for a mercury cell, which could be switched in in place of the solar cell.

A much smaller version of the selenium solar cell can be seen in this Popular Mechanics advertisement for $1.

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25 March 1941 Maine Snowstorm

Images from another winter storm. NOAA photo.

Images from another winter storm. NOAA photo.

Seventy-five years ago today, March 25-26, 1941, central and northern Maine were hit with a severe storm that did considerable damage to telephone and telegraph lines. Strong winds and heavy wet snow took down many lines, and most of the northern part of the state was cut off from any wire communications.

The telegraph companies contacted W1BAV who established communications with Presque Isle and relayed instructions to the service men there. By night, lines were reestablished to many parts of the state.

Between 7:30 and 9:30 PM on the night of the 26th, hams had most of the state hooked up and standing by. By 9:30, the telegraph companies had established enough service so that they were able to advise the hams that they could stand down.

These details were recounted by Maine Section Communication Manager H.W. Castner, W1IIE, in the July 1941 issue of QST.

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EICO 753, “Seven Drifty Three” Review, 1966

Eico753

Fifty years ago, the February-March 1966 issue of Radio TV Experimenter magazine published a review of the Eico 753. This was a bare-bones SSB and CW (with AM tossed in as an  afterthought) transceiver for 80, 40, and 20 meters. I happen to own one of these monsters, and it’s actually a nice radio for what it is. I’ve worked DX with it, and I even took it with me on a mini-DXpedition to YV-land. I worked a few stateside stations from there, and even worked Europe on 40 phone.

The review was generally favorable, concluding that “so far, the EICO 753 stacks up as the best ham transceiver buy for 1966.

The radio is affectionately known as the “Seven Drifty Three” for its propensity to drift. The review covers this point:

After a 15 minute warmup the EICO 753’s stability was well within the specified 400 cycles–in fact, we were able to work relatively long contacts with but one or two tuning corrections (done with the receiver offset). We must allow for the other ham’s station having some drift.

In 1966, the radio sold in kit form for $179.95, $299.95 wired. Unless you had a power supply, you would need that as well. The AC supply with speaker sold for $79.95 in kit form, $109.95 wired. Mobile power supplies were available for the same price.

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Fay Wray, 1926

1926FayWray

Ninety years ago, this date’s issue of Radio Digest, February 20, 1926, featured this picture of eighteen year old Fay Wray, who is probably best remembered for her role in the 1933 film King Kong.

Her fame on the cover of this magazine was a result of her being named one of the thriteen WAMPAS Baby Stars for 1926, in a program broadcast by KNX in Los Angeles.  The honor was conferred by the Western Association of Motion Picture Advertisers, which each year honored thirteen young actresses believed to be on the threshold of stardom. Other familiar names in the class of 1926 included Mary Astor and Joan Crawford.

Canadian-born Wray resided in Hollywood, and had appeared in a number of minor roles. After the recognition brought about by the WAMPAS award, she was contracted by Paramount, where she made more than a dozen movies. Her most famous role in King Kong was for RKO.

She died in New York in 2004 at the age of 96. Two days later, the lights of the Empire State Building were extinguished for fifteen minutes in her memory.



1936 3 Tube AC-DC Portable

1936FebPS

The February 1936 issue of Popular Science shows the plans for this simple portable receiver. “By careful planning and the use of midget parts and space-saving metal tubes, a complete three-tube circut, loudspeaker and all, has been crammed into an ordinary cigar box.” Despite the small size, it could “be built by anyone who boasts a jack knife, a pair of pliers, a screw driver, a soldering iron, and a small drill.”

The circuit consisted of a 6K7 serving as RF amplifier and detector, with a 6C5 serving as audio amplifier to drive a three-inch speaker. A second 6C5 was used as rectifier. A “curtain burner” cord was used to reduce the line voltage to 18 volts in order to light the filaments of the three tubes wired in series.

In testing, the set gave good volume on more than a dozen stations, with a sixty-foot outside antenna.

 

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Making Your Own Plug-In Coils

1941FebPMCoils

1940PlugInCoilsMany of the vintage receivers described here require plug-in coils, such as the ones shown in the image at the left. Back in the day, these were readily obtainable in common sizes. And as the February 1941 issue of Popular Mechanics pointed out, “considerable effort can be saved by purchasing ready-wound coils.” However, he magazine also admonished that “the beginner should take the time to wind the coils for at least the first set he builds so that he will understand exactly how they are made,” as the young gentlemen shown at the top of the page are doing.

Today, since pre-manufactured coils are unobtainium, the builder of one of these sets has little choice but to make the coils at home. But as the experimenter 75 years ago learned, the process of making coils is quite simple. This article serves as a good guide for the modern recreator to make the coils. But there is still a slight problem, since the article simply advises purchasing “forms usually made of Bakelite or similar material.” And those coil forms are also unobtanium today.

Fortunately, modern materials come to the rescue, since it’s easy to recreate the forms themselves using readily available PVC tubing, along with the base of a defunct tube. Complete instructions can be found on AA8V’s page.

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6GZ, Bakersifeld, CA, 1916

1916FebPM

Shown here is the radio station at Kern County High School, Bakersfield, California, as depicted in the February, 1916, issue of Popular Mechanics.  The accompanying article notes that the school has a course in wireless telegraphy, with a course in wireless telephony being added.

According to the 1916 call book, the station was licensed as 6GZ, under the control of one A.J. Ludden.



National Parks On The Air “Park To Park” QSO

Photo of bridge at Chickasaw National Recreation Area

Chickasaw National Recreation Area, Oklahoma. NPS photo.

I had my first “park to park” QSO today in the ARRL National Parks On The Air (NPOTA) event.  On the way to do some grocery shopping, I decided to make a quick stop near the Mississippi River, at a parking lot just south of Summit Avenue on the St. Paul side of the river.  It’s at a fairly good elevation above the water, but it’s within the required 100 feet of the river.

I worked about 35 contacts on 20 meter CW in about a half hour, as shown in the log below.  When the pileup subsided, I decided to try phone.  In a previous “activation” from this location, I had managed to work about 50 contacts, but that was after I was “spotted” on the DX cluster.  Without that help, my 5 watt signal didn’t attract anyone’s attention on the crowded band, and I called CQ for about 10 minutes without any takers.  Before packing up, I decided to tune the band and look for any other strong signals.

After a few minutes, I heard Gary, N5PHT, who I had already worked a few times from home.  He was operating from a campground at the  Chickasaw National Recreation Area in Oklahoma.  He had a booming signal and easily pulled my weak signal out of the noise.

Gary’s station is described on his website.  The difference in signal is attributable to the fact that he is running 100 watts to a better antenna, with a nice station set up in his motorhome.  Even though he was portable, he had a formidable signal, and has worked about 2000 contacts in about a week from this portable location.

 

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