Category Archives: Radio history

1926 Parks On The Air

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One hundred years ago this month, these proto-POTA hams were on a camping trip, and their natural inclination was to bring along a rig and make a few contacts.

In 2016, the ARRL’s National Parks On The Air (NPOTA) program brought a boost to operating from parks. After that program ended, it gave a boost to the already existing Worldwide Flora and Fauna (WWFF) program, from which Parks On The Air (POTA) spun off. But for many hams, including myself, operating from remote portable locations has always been a natural.

This picture appeared on the cover of QST, August 1926.



1951 Western Union Telecar

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Shown here on the cover of Radio-Electronics magazine, July 1951, is a Western Union messenger in a specially equipped telecar. The last mile was a challenge for Western Union delivery of telegrams. In the central business district, a messenger could be dispatched from the office. But in residential areas, the system was not efficient. Therefore, Western Union equipped vehicles with a two-way radio and facsimile machine. Even when unattended, the fax would print out an incoming telegram, delivered by 30-50 Mhz radio, and the messenger would quickly deliver it to an address in his area. According to the magazine, the system was already in operation in Baltimore.



1966 Six Meter Superregen

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Shown here on the cover of QST for July 1966 is a transistorized “rush box” superregenerative receiver for 6 meters, designed by Technical Editor Doug DeMaw, W1CER (later W1FB).

The main design consideration was low cost, but the circuit was very sensitive. And it put out two watts of audio, making it suitable for use in noisy environments.



1966 Two-Transistor TRF

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Sixty years ago this month, the July 1966 issue of the British Radio Constructor carried the plans for this two-transistor TRF receiver for the medium wave band. The magazine noted that the TRF (tuned radio frequency) set would never match the performance of a superhet, but for the beginner, it was easy to understand and build, and no complicated alignment procedures were necessary.



1941 Crosley Displays

No, she’s not pedaling to power the radio. And if you look carefully, she’s just a cardboard display. This is actually a retail display for Crosley radios, as shown in the July 1941 issue of Radio News. The magazine notes that it’s not enough for a radio retailer to just have the product. Also needed are effective sales aids, such as these.



1966 FM Wireless Mike

Sixty years ago this month, the July 1966 issue of Popular Mechanics showed how to make this FM wireless mike. Construction was simple, since a printed circuit board was available, and there wasn’t really much that could go wrong. A supplier of the circuit board ($1) or a complete set of parts ($8.95) was provided.

The tuning procedure was explained, and the magazine stressed that to comply with FCC rules, you had to pick a blank spot on the FM dial. Transmitting outside the band was strictly prohibited. And undoubtedly, all builders followed this admonition: “The transmitter should be tested by a competent electronic technician. He should determine that the unit meets FCC requirements and give you a written statement to this effect. Attach this certificate to your transmitter.”



Vacuum Tube Criminal: 1956

Shown here are the mug shots of Joseph Bernard Lynch of Boston. When his cellmates asked him what he was in for, he would have to tell them “tube rebranding.”

His scheme is exposed in the July 1956 issue of Radio News.  He bought bad tubes for two or three cents each. The magazine noted that the sellers should have been suspicious, because there was no legitimate use for them. He then fraudulently rebranded them, and labeled them to show that they were still under warranty. He then returned them to the manufacturers and got replacement tubes, which he sold at a discount.

But the long arm of the law eventually caught up with him, and he was sentenced to two years. The magazine gives his address as 82 Carver Street. That was apparently the bad side of town. The address no longer exists, having given way to urban renewal in the 1960s.



1941 Five Tube Superhet

Eighty-five years ago this month, the July 1941 issue of Radio News featured the plans for this five-tube superheterodyne for hams. The set covered the shortwave spectrum with plug-in coils to cover 1.7 through 32 MHz, and featured a BFO for CW reception.

The circuit doesn’t look unfamiliar, as it’s not that different from a typical All American Five, but has an IF of 1500 kHz, which seems like it would leak through if you had a broadcast station on that frequency and didn’t have it well shielded.



1951 4-Tube Regen

Seventy-five years ago this month, the July 1951 issue of Radio Electronics carried this circuit for a four-tube shortwave regenerative receiver. The circuit was provided by the editors in response to an inquiry from a reader, who specified these specific tubes. They are familiar as coming from an “All-American Five” AM radio, so they were, and still are, easy to find.



1945 One Tube Regen

Eighty years ago, the September 1945 issue of Radio Craft magazine carried this circuit for a simple one-tube regenerative receiver, which had been sent in to the magazine by one Jim Gary of Kenedy, Texas. With a good antenna and ground, he reported that he had pulled in both New York and San Francisco with the set, which could be built in a cigar box.

B batteries were hard to come by during the war, and this circuit ran on four flashlight batteries. One powered the filament, and the other three provided the 4.5 volts of B+. With that low voltage, a large tickler coil was necessary for regeneration.

It appears that the author was 17 years old, having been born in 1928, and he passed away in 2001.