Seventy years ago this month, this gentleman was aligning the radio direction finding (RDF) receiver he had constructed according to plans in the the May 1955 issue of Radio-Electronics. The magazine noted that ferrite loop antennas had simplified the design considerably. It even recommended going ahead and building one even if you didn’t have a boat: “You can build one and use it yourself or give it to a cruising friend, thus insuring yourself of a boating trip anytime you want. This model has been designed with the simplest of construction and can be made of surplus and junkbox parts. But it will give bearings as good as the fanciest job afloat.”

By turning up the gain, the set could also copy CW signals, which shared the same frequency range as beacons. It also pointed out that A-N Beacons for aviation could be found in that band.

Seventy years ago this month, the April 1955 issue of QST contained the plans for this miniature station. Dubbed the “Tiny Tim,” the station weighed in at a mere 18 pounds, including batteries. It could be used for CW on 80 and 40 meters, and the self-contained station made you ready for any emergency, or for plenty of fun from home, on a boat, at the beach, climbing a mountain, or wherever.

The receiver was a two-tube regenerative. The author, Stuart D. Cowan, III, W1RST (later W2LX) advised that a single coil could be used for both bands, but it was better to use separate coils for enough bandspread.

The transmitter was almost identical to the 1947 “Last Ditcher” that we previously featured. It ran about two watts, using a 1JG6 twin triode operating as a push-pull crystal oscillator.

An antenna was mounted on the side of the set, and was a base loaded four section automobile antenna from Montgomery Wards.

The author noted that his 11-year-old son, WN1BRS, assisted with its construction and manned the home station during tests. According to the 1954 call book, the son was Stuart A. Cowan, who is also listed with his novice call sign in 1955. However, he is no longer listed in the 1956 call book, meaning that he didn’t upgrade to General in the one year of his novice license.

Seventy-five years ago this month, the April 1950 issue of Popular Science showed how you could, for about $2, convert your radio to pull in signals from Europe, Africa, China, and other locations. Specifically, it showed how to convert an “All-American Five” receiver to pull in shortwave signals.

The first step was to add a 4PDT (actually, a 3PDT would work, but weren’t generally available).  This was actually the trickiest part, since space might be tight.  The article cautioned that you might need to shop around to find one small enough.  With that done, you added the new wiring as shown below (in pictorial and schematic diagrams).  You added new antenna and oscillator coils to be switched in, and also added a terminal for an external antenna in series with a capacitor.

The last step was to add a dial scale to the front of the radio, which could be on a piece of cardboard.  The set would now tune 17 to 40 meters, and back to the standard broadcast band at the flip of a switch.

This small ad appeared a hundred years ago today, in the April 26, 1925, issue of the Washington Evening Star. It illustrated just how popular radio had become. Not only were radios being advertised in the newspaper, but for those who already owned a radio, there were advertisements for radio knobs.

The knobs in question were E-Z-Toon knobs from the E-Z-Toon Radio Company, 3234 W. Washington St., Indianapolis, Indiana.  As the name suggested, the knobs would make the radio easier to tune, especially in the problematic summer season, with a vernier drive.  If you’re looking for an example of an E-Z-Toon knob, you can find it at this e-bay listing.

Seventy years ago this month, the April 1955 issue of Popular Electronics showed how to put together this simple two-tube (including rectifier) transmitter for the 80 and 40 meter bands. It was dubbed the Hart-25 and designed by Hartland Smith, W8VVD (later W8QX), whose later Hart-65 transmitter we’ve previously seen.

Smith was a prolific writer and kit designer, and you can find a number of his other projects on this site at this link.

This transmitter had about 25 watts input, and delivered about 9 watts to the antenna. Tune up was accomplished by observing a pilot light in series with the antenna while adjusting the output capacitor, as well as a trimmer in line with the antenna. There was a switch for shorting out the lamp. The article noted that you could turn it on occasionally to check the output, but it should be left shorted out most of the time, as it would consume power that would otherwise go to the antenna.

This video shows the transmitter in action:

Sixty years ago this month, the April 1965 issue of Popular Electronics showed the simple process for converting a Knight Kit C-100 walkie talkie to the ham bands. The author, Harland Smith, W8VVD, later W8QX, noted that a walkie talkie is handy for hams in many situations, such as staying in touch with friends at a hamfest, adjusting an antenna, or tracking down TV interference. But there were no low-cost units available for the ham bands.

He showed how simple it was to convert the $9.95 C-100 to 10, 6, or 15 meters. For ten meters, the set needed only a new crystal and a bit of retuning. For 15 or 6, it required rewinding a couple of coils.

One hundred years ago today, President Calvin Coolidge opened the Chicago Woman’s World Fair by Radio, as shown here in the Washington Evening Star, April 19, 1925.

The event, held at the Chicago Furniture Mart, spanned a week, and was attended by over 180,000, and celebrated women’s achievements in science, art, and business.  In his opening remarks, Coolidge proclaimed that “for long ages past, men have gone forth into the world, more recently they have been followed by women. Each are endowed with the same desire, each attempting to contribute to the satisfaction of the universal longing of the human race to bring something better home. ”

According to the event’s program, among the occupations represented was that of Radio Broadcaster.

Sixty years ago today, “Conditional Territory” in the United States got smaller.

The Conditional Class amateur radio license had privileges identical to the General Class. But instead of taking the exam in front of FCC employees, prospective licensees living far away from FCC exam locations could take it through a volunteer examiner. Until 1965, this applied to those who lived 75 miles away from an exam location. But starting on April 15, 1965, the distance was changed to 175 airline miles. And as long as an exam was given at least semi-annually, that location qualified. As a result, the areas eligible for a Conditional license got much smaller, as shown on the map above. The majority of the population was now ineligible.

The FCC realized that this might be a particular hardship in some cases, and they would entertain requests for waivers. But in most cases, rural hams now needed to make a trip to the closest FCC exam location.

The map appeared in the April 1965 issue of QST.