For a snapshot of how the radio spectrum was allocated 80 years ago, this chart appeared in the March 1942 issue of Radio Retailing. You can click on the image above for a full-size image, and on most browsers, click again to enlarge.

While America was now in the war, the allocations above are really the last prewar allocations, as they would have appeared on December 6, 1941. Since then, for example, Amateurs had left the air for the duration. At the time, the amateur bands were on 160, 80, 40, 20, 10, 5, and 2-1/2 meters. Postwar, the allocations would be similar on 160 through 10, with the addition of the 15 meter band a few years after the war. The VHF allocations shifted slightly to 50 and 144 MHz.

With some changes, the TV channels were in their postwar configurations. FM broadcasting would move from the 42-50 MHz band up to its present allocation at 88-108 MHz.

Eighty years ago, the January and February 1942 issues of the British magazine Practical Wireless showed the construction details for this three tube emergency receiver. The magazine had received many demands for a receiver capable of good performance on the medium waves, but with components that could be obtained with a minimum of difficulty, given the wartime conditions. The editors settled on this three tube design, with one tuned RF stage, which was found to perform adequately, but “shorn of refinements which would normally have been incorporated in times when components were easily and quickly obtainable.”

The main design was published in the January issue, with the February issue showing some refinements that would make the set more sensitive and selective. The February issue also showed how a two-tube version could be made, which might be necessary due to wartime parts shortages.

The regeneration control on this set is interesting, and something I haven’t seen before. It is a variable differential capacitor, which has two separate stators, and one rotor. The idea is evident from the diagram symbol. They are also sometimes called a split stator variable capacitor, and they apparently are a thing.

As we previously reported, as of January 5, 1942, enemy aliens (that is, citizens of Japan, Germany, or Italy) were prohibited from possessing cameras, firearms, or shortwave radios. They were required to surrender them at the police station, where they would be issued a receipt.

The February 1942 issue of Radio Service Dealer reminded its readers that the majority of such aliens were friendly to the country and should be accorded fair treatment. It was essential to keep in mind, however, that not all of them were. The magazine also pointed out that there was no intent to deprive enemy aliens of the opportunity of listening to American broadcast stations. Therefore, the regulations permitted persons to reclaim their receivers if it was made inoperative on the shortwave bands. Hence, there was a demand for technicians to perform the necessary task of disabling shortwave reception on multi-band sets.

The magazine stressed the need of doing so in a manner that could not be easily converted back. Therefore, simple modifications such as cutting a lead to a band switch, or shorting out oscillator coils, was insufficient. The magazine provided the technical details for various kinds of sets. Some sets, for example, used a single oscillator coil for both broadcast and shortwave, with the coil tapped for shortwave reception. These sets might require replacement of the oscillator coil. Other sets used separate coils for the different bands, and these were generally an easier job of simply removing the shortwave coils.

After the job was done, there was still a need for caution:

Remember that there is always the possibility that some enemy alien in your locality may try to pull a fast one. Dealers, jobbers and servicemen, and radio amateurs, too, should be suspicious of any person who may be presumed to be an enemy alien, when attempts to purchase radio parts, borrow test equipment, or seek your service in any alignment work outside of  the broadcast band.

On the other hand don’t let your imagination get the better of you. Be reasonably sure of your suspicions before reporting any case to the local police or the FBI.

The magazine contained the full text of the regulations:

Short-Wave Radio Receiving Sets

(a) No alien enemy shall use, or operate or possess, or have under his custody or control at any time or place any short-wave radio receiving set. For this purpose the words ‘short-wave radio receiving set’ are to be construed as including any apparatus designed to be used or capable of being used for the purpose of receiving signals, messages or communications of any nature whatsoever which signals, messages or communications are transmitted by means of radio waves of a frequency of 1750 kilocycles or greater, or of a frequency of 540 kilocycles or less.

(b) A short-wave radio receiving set as defined in paragraph (a) hereof which set is also capable of receiving long-wave radio communications is deemed to be within the class of shortwave radio receiving sets prohibited unless the set is so altered or modified that short-wave radio communications or messages cannot be received by the said set, and further, unless the set is so altered or modified that it is impossible without the addition of more parts and the substantial rebuilding of the set to modify the set so that it will be capable of receiving short-wave radio communications.

( c) No alien enemy who is found in possession of any short-wave radio receiving set will be excused in any manner on the ground that he did not know that the set was a short-wave radio receiving set or that the set could be readily converted into a short-wave radio receiving set. It shall be the duty of any alien enemy to ascertain whether or not any radio in his possession is prohibited; and any alien enemy having in his possession any radio receiving set whatsoever shall be held responsible for knowing whether or not such set is a short-wave radio receiving set.

The magazine apparently needed an appropriate photo for the cover to illustrate this important story, and it settled on this image of an SWL, apparently pulling in an English station. The caption noted that this activity was one now reserved to citizens only.

It’s not uncommon for radio collectors to come upon a prewar set whose shortwave bands have been disabled. For those with such a set, we hope this article provides some insight into the modification that had been made in early 1942.

Shown here 70 years ago is Joseph J. Pekot of Nanticoke, PA, on the cover of the February 1952 issue of National Radio News.  Pekot had always driven a coal truck, but after being discharged from the army, he wanted to enter a field of study that would always be expanding. Since electricity and radio had always interested him, he enrolled in the National Radio Institute correspondence course, and kept his job while he studied at home. He graduated in 1948 and did complete service work in his part-time shop. He reported many satisfied customers.

Pekot, who fought at Normandy and the Battle of the Bulge, earning five Bronze Stars, died in 2001 at the age of 84.

This interesting short story appeared 80 years ago in the January 1942 issue of Radio Service Dealer. The story appeared in the magazine’s “Serviceman’s Diary” feature written by contributing editor John H. Potts.

The story must have been written days after Pearl Harbor, and the author is fantasizing about an air raid warning. Ordered to shelter by a police officer, a radio repairman found himself in front of a big apartment building. Somewhat counter-intuitively, he remembered that the safest place would be on the third or fourth floor, so he went to the third floor and rang the bell of the first apartment he saw. An attractive woman answered the door, and the story has its happy ending when she falls for him after he is able to fix the radio.

It’s an interesting prediction of home front life early in the war, and makes an interesting read:

Eighty years ago, these gentlemen probably realized that they would soon be serving in the armed forces, and their stint would probably be more comfortable if they came to their induction in possession of a skill useful to Uncle Sam. Therefore, they have undertaken to learn Morse Code, thanks to this one-tube oscillator described in the January 1942 issue of Popular Mechanics.

The set used a single 117L7-GT tube, whose 117 volt filament meant that it could run straight off the AC power lines, without worrying about dropping resistors or transformers. It had plenty of volume, which could be controlled with a volume control, to drive a speaker or up to 20 pairs of headphones for group practice.