We recently wrote about this three-transistor regenerative receiver from the January 1958 issue of Boys’ Life magazine.
I just received this picture of the completed receiver, constructed by Tom, WB3HLH, of Rockville, Maryland.
As a Cub Scout, he saw the receiver in the magazine and was very interested. This is understandable, since the magazine also carried a feature extoling the virtues of SWL’ing, as well as a listing of the prizes in the annual radio contest.
About 50 years later, he located the magazine and took it upon himself to make one. The article noted that the set was not for beginners, and his experience agrees with this assessment. He notes that the audio stage was simple, but it was very tricky to get the detector oscillating. As you can see, he very carefully duplicated the layout of the original project.
In addition to the coils described in the article (wound on plug-in coil forms), he wound a coil for the broadcast band. He reports that the set performs well on shortwave, both for broadcast and SSB signals. On the broadcast band, it pulls in all of the major East Coast stations, and signals as far west as KMOX in St. Louis.
The article calls for the use of four penlight batteries, but he reports using a 9 volt battery. The only other circuit modification is the addition of a 3.3 k resistor in parallel with a .01 uF capacitor on the emitter of the detector transistor.
This article was the ‘light in the dawn’ for an 11 year old geek ( the world did not have geek in their lexicon, but the strange boy who was interested in science stuff, destined to be scoffed and teased), who had heard SW stations on his grandparent’s Zenith radio and was entranced with hearing sounds from somewhere else……. I had access to NYC’s Cortland St (Radio Row) to wander through the rows and stacks of Surplus electronics……. Able to find the Coil forms, and the National tuner assembly, and all the capacitors mentioned……… BUT, the transistors were unobtainium……. The same little wannabe ham, who wrote a letter directly to Raytheon development… to ask for circuit help and maybe free samples of the 2n114, and the CK722s…… Only to be responded to! Not only with a package of FREE CK722s and 2N114s from the engineering department, but with suggestions and a modified schematic that had been breadboarded in the Raytheon lab………….. That set of exchanges was the fertilizer for an 11 year old nerd, who routinely had his notebook thrown around the school bus, while he tried to retrieve it…….. I think I might just have my version of the project up in the attic, it oscillates, it receives the strong signals, it makes morse code sounds, and the kind Raytheon engineers succeeded in creating an IBM Senior Engineer/Computer Scientist, who also worked for years in the DoD…………… who is 73 years old and just as curious about the world and what makes it tick!