In 1939, Motorola introduced a small portable AM radio, the 41-S “Sportsman.” Just look at that. Smaller than a six pack. Quite a feat in 1939.
It was not, however, the smallest–that honor goes to the Majestic model 130, a three tube set. BUT. For a conventional 4 tube superheterodyne AM receiver that used full sized chassis components and tubes, it was a pretty impressive packaging job and when judged by the 4 tube standard size parts criteria it is easily the tiniest of the time. The tubes used were the bantam octal types and the A supply was 1.5v with an 81v B supply for the plates. Rather than a typical 90v supply as was done with other portable sets, 81v was chosen–likely because it made the battery a little smaller while still yielding good performance. To further reduce the overall package size, this 81v supply was divided between TWO separate batteries that allowed it to be fitted around the speaker and other components. You can see this in the tag on the inside of the bottom cover.
In addition, the necessary antenna loop was wound as strands of litz wire within the shoulder strap that was used to carry or wear the set which also contributed to an overall size reduction.
There are very few of these sets left. This is due to several factors. First of all, they simply did not sell that many to begin with–pure DC battery only portables just weren’t that common…….and next, advances made during the war allowed further refinements and these were simply obsolete by the 50’s……and then…the final blow to tube based portable radios–the first commercially sold transistor pocket radios which were introduced in 1954 with the Regency TR-1.
The Motorola 41-S, however, suffered an even shorter life that make them scarce today. A vicious cycle that was the direct result of the 81v B battery supply lead to its early demise. This is not a technical problem, but far more insidious…it is the result of being too specialized in the face of supply and demand. Dividing up the 81v supply into one battery of 51v and another 30v made for tighter packaging, but the Motorola 41-S was the ONLY set made that did this. The batteries that Burgess and others made for it were made ONLY for this set. They had no other application. When the US entered the war in December of 1941 there was a rapid shift to wartime production. Many products for civilian use were limited or taken out of production altogether. Batteries, like many other goods, were rationed. These batteries, because the application was so specialized and the number of the sets so few, were taken out of production for the duration of the war. This resulted in many of these radios, now unable to be powered, getting dumped at the scrap drive, cut up for parts to keep other sets working, or–if lucky, being tossed in a trunk or closet for the rest of the war. Then….after the war, production of consumer goods resumed, rations were lifted…….but…these batteries were not put back into production because by this time, the number of these sets had dwindled to the point that there was no benefit for the large manufacturers to make them again. A victim of a vicious cycle, the remaining sets after the war either got dumped, robbed of parts, or forgotten for many years. The lucky few to have been stored and overlooked have thus made the final cut.
It is good that Motorola used standard types of parts in their innovative packaging arrangement. This makes these sets fairly easy to repair and restore. Today the battery issue can be resolved by a dedicated enthusiast by selection (and soldering) of a variety of commonly available cells to make the required supplies in a form that will fit the battery compartment. Those lucky enough to have found one of these lucky survivors can get them playing again and show off one of the very first truly personal sized music players. Go on…rock out with the Ipod…Prewar style.
