Eighty years ago today, the May 19, 1941, issue of Life magazine carried this ad for a Zenith portable. While the model number isn’t given, it appears to be model 6G601.  The six-tube set ran from a non-rechargeable battery pack, or from AC power.

The distinguishing feature of the Zetith portable was the Wavemagnet antenna.  This was a loop antenna contained in a cardboard cover that looked like a horseshoe magnet.  It came with suction cups to attach it to the window of a car, train, or building.  The compartment with the antenna also had a storage area for headphones for private listening or for the hard of hearing, although they were an optional extra.

The set retailed for $29.95 with airplane fabric cover, or slightly more for genuine cowhide.  Prices were also slightly higher in the west.  According to this inflation calculator, that works out to the equivalent of $544 in today’s money.

If the set looks familiar, it’s because we’ve featured it previously.

A demonstration of a nicely restored example of this set can be seen in the video below.

z
Sixty years ago, the May 1961 issue of Radio Electronics showed how to assemble this four-transistor pocket radio. Many items of this era were billed as being “about the size of a pack of cigarettes,” but this one really was. The cabinet was constructed using a cigarette flip top box.

The magazine gave detailed instructions for constructing it. The first step was to carefully cut off the top where it hinges. Various slots were added, and additional cardboard inserts were placed inside for various compartments. At this point, the cardboard box was painted with two coats of Duco household cement, thinned down to a paintlike consistency with laquer thinner or nail-polish remover.  After this was thoroughly dry, you would paint the box with your favorite color enamel and let it try for a few days. The top would be sanded lightly or steel wooled to allow the top to fit back on snugly. The finishing touch was calibrating the dial with the customary markings of 53 through 16 with a “toy printing or rubber-stamp set.” Each number was held with tweezers, coated by a piece of glass with a thin coat of paint, and pressed to the case.

Blueprints for the cardboard cabinet.

The chassis could be a standard printed circuit board, and the magazine showed the pattern. Or, another option was to build a circuit board using another piece of cardboard treated with the diluted Duco.

After all that work building the handsome cabinet, you wouldn’t want to skimp on the electronics, and this circuit didn’t. It used a Philco AO-1 transistor as the regenerative detector, along with three of the venerable 2N107 transistors as audio amplifier. The receiver was tested by the publisher, and performed quite well. From the test location 20 miles from New York City, the set was able to pull in nine stations with good earphone volume. It noted that it probably could have heard more stations with careful tuning. The loudest station, which was seven miles away, was loud enough to be heard by two persons with the earphone in a small dish on the table between them.

The author reported similar good results at his location. He noted that it was very selective over the entire broadcast band. He reported at night hearing stations 400 miles away, and three stations 1500 miles away. He also reported that on local stations, he could listen with the earphone six feet away.

This utilitarian but handsome receiver graced the cover of the May 1951 issue of the British magazine Radio Constructor. That issue, as well as the June issue, described the circuit and provided details on putting it together. According to the author, the magazine had received numerous requests to design such a set, and those requests asked that the set should be easy to construct, compact, and provide a pleasing symmetrical cabinet.

Those requirements posed a tall order, but with some experimental work, this set, dubbed the “Constant Companion” was the result. The three-tube (including rectifier) circuit tuned the long and medium wave bands, and provided loudspeaker volume with a suitable antenna.

The Novice Class license was first authorized by the FCC effective July 1, 1951. Actually, July 1 was a Sunday, so the first exams probably took place on July 2, with the licenses arriving several weeks thereafter. Novices were allowed to operate initially on CW on 80 meters (3700-3750 kHz) and on the old 11 meter band (26.96-27.23 MHz), as well as both CW and ‘phone on 2 meters (145-147 MHz). The June 1951 issue of QST carried a feature “How To Pass the Novice Examination,” and included the 28 question study guide for the 20 question multiple-choice test.

The May and June issues also carried the plans for a simple transmitter for the novice to get on the air. The set was designed by ARRL Technical Editor Don Mix, W1TS, who pointed out that a higher power transmitter, or one on the 11 meter band, might require additional shielding or other precautions to avoid television interference. The simple circuit here, however, was capable of contacts even with an antenna as short as five feet, although longer was, of course, recommended. The retail cost of all of the transmitter components was only $15, and the set required only four hand tools to put together: screwdriver, pliers, hand saw, and soldering iron. The chassis consisted of a board, and the tube socket was mounted horizontally on two metal angle pieces.

The May issue showed how to put together the transmitter, and the June issue showed an accompanying power supply as well as ideas for an antenna. The author reported that with brief tests from West Hartford, Connecticut, he was able to put stations in Wisconsin and Florida in the log at night, with Maine and Pennsylvania during the day. The set was designed to run to a random wire, and some ideas for the transmitting antenna are shown here. A long outdoor antenna was, of course, recommended, but if necessary, and indoor antenna could be used, and the set would load up into an antenna as short as five feet.