Sixty years ago, domestic tranquility was restored in this household, as shown in this picture from the October 1957 issue of Popular Science.  Dad and Junior can watch the fight, while Mom and Little Sister work on the piano lessons.

This major breakthrough was accomplished after extensive testing by the editors of the magazine. Every TV owner had been waiting for the good news: “a simple way for each member of the family to turn the sound off or on, to suit himself, without annoying anyone else.”

The magic that made this possible was the inductive loop. Because the headset was wireless, “there’s no dangling cord to tether you to the console.” The headsets could be made in a couple of hours, and the magazine proposed three varieties.

The modification of the set and the installation of the loop was an almost trivial matter.  The magazine warned to unplug the set and let it sit for 15 minutes “for the tubes to cool off” (and hopefully for the electrolytics in the power supply to lose some of their charge).  Then, the lead to the speaker was snipped and hooked to the inductive loop, as shown here.  The magazine recommended adding the closed-circuit jack shown in the circuit here, so that the loop could be unplugged on those occasions when the speaker was desired.

The loop could be run under the carpet, as shown here, tucked away near the ceiling, or even placed in the joists in the basement below.  While reception was best when the headsets were at the same level as the loop, the magazine’s tests showed that any of these arrangements would work well.

This loop formed the primary winding of a room-sized audio transformer.  The secondary windings would be in the individual headsets.  For the kids, the magazine recommended the spaceman style shown here, with the assurance that the kids would love them.

As revealed by the diagram below, these headsets were simplicity itself.  The coil was worn around the head, and hooked directly to the headphones.  The magazine suggested that Mom should be put in charge of suitably decorating the loop with colored tape.  No other electronics were necessary for these headphones for the kids.  The output of the coil was sufficient to drive the headphones.

Mom and Dad warranted somewhat more discrete looking receivers, and these could be either of the models shown below.  Mom had a version similar to the kids’ version, but the loop was not worn.  It was apparently thought that she could set it in a convenient spot, and it was hooked directly to a small earphone.  The magazine noted that the earphone was so small that it could hardly be seen.  The only problem that might result would be forgetting to take it off before going to bed!

Dad is seen using a slightly more complicated version, but still easily within the capabilities of anyone able to wire up a lamp cord.  It used a much smaller coil, amplified with the venerable CK722 transistor.  It was the size of the proverbial pack of cigarettes, and the two penlight batteries would keep it running for a thousand hours.

Those wishing to duplicate this idea today can save a great deal of coil winding time by using a telephone pickup coil instead of winding the coils for the individual receivers.  If a set of high-impedance headphones is available, it could be fed without any electronics.  The CK722 is more or less unobtainium, except at very high prices.  But any small audio amplifier could be put into service.  If you want to make your own, hundreds of circuits are available using the readily available 2N2222 transistor.

Seventy years ago, television was finally becoming a reality. The war was over, stations were coming on the air, and the enlightened radio dealer was getting ready to move into television. Crosley, the pioneer in radio manufacturing and broadcasting, had also made the move to television.  The Crosley Spectator is shown here, from the August 1947 issue of Radio & Appliance Journal.

The set boasted an image size of 6-3/8″ by 8-1/2″, had 27 tubes and three rectifiers, and tuned all 13 channels, 44-216 MHz, including the elusive channel 1, which was never put to use.

Those 27 tubes consumed 380 watts, and the set weighed in at 85 pounds.

The ad assured the dealer that the Spectator in the shop window as its own salesman, and each set sold would become the talk of the neighborhood and draw in even more business.

You can see a nicely restored example of this set in operation at this video:

Sixty years ago, solar activity was at an all-time high, and the sun was plastered with sunspots. This was good news for hams, who depend on this solar activity for ideal radio communications on the high frequency bands. But in addition to being literal dark spots, this was, figuratively a dark time for the hapless TV repairman in fringe areas, because it fell upon him to explain to his customers that their interference woes weren’t his fault, but were instead caused by blotches on the sun.

Fortunately, the TV repairman got some sympathetic advice from this article in the August 1957 issue of Radio Electronics.

It starts by noting that Sunspot Cycle 19 was about to reach a peak, which was good news for hams and shortwave listeners, for whom shortwave propagation would be better than at any other time in history.

But the average TV owner “probably does not care about receiving Havana, Cuba, or some other distant TV station over his favorite local channel,” which was a distinct possibility in fringe areas. The article noted that this would be particularly an issue for channels 2, 3, and 4.

The article counseled the serviceman on how to deal with these calls. And unfortunately, there was little that could be done, other than to “explain to the owner what is happeninng and that the condition will probably pass in a short while. Ask him to call the next day if the trouble is still there.”

The article suggested that a good way to educate the customer would be to draw a sketch of the earth and ionosphere as shown above. While reorienting the antenna might help in some cases, the best advice was to hope that the owner understood what was happening. If the customer understood, it would make him “less likely to call a service technician and thereby leave the technician more time to devote to true television troubles.”

Twilight Zone “Long Distance Call” 1961. Wikipedia image.

You might recall the 1961 Twilight Zone episode “Long Distance Call.”  If you don’t recall, five-year-old Billy received a toy telephone from his grandmother, who then promptly died.  After her death, Billy continued to receive “pretend” phone calls from her, in which she encouraged him to join her in the hereafter.  Finally, the father stepped in, picked up the toy phone, and told Grandma, in no uncertain terms, to knock it off.

We offer a possible explanation from just

Youngster listening to 1947 toy phone, presumably tuned to strong local station.

fourteen years earlier, in the June 1947 issue of Popular Mechanics.  That article showed how to convert a toy telephone, which looked just like Billy’s, into a crystal set.

According to the article, Daddy really made a hit with his youngster by doing the conversion, and the youngster was, indeed, able to hear voices through the toy telephone, in the form of a pre-tuned local radio station.

The conversion entailed use of a 1N34 diode, and tuning was accomplished by a premeability-tuned coil. Dad presumably preset the tuning to the strong local station, although I suppose it’s possible that he accidentally tuned it to the hereafter. The earphone that the author was able to find was a war surplus low impedance unit, necessitating the addition of an audio output transformer.

Billy’s telephone just 14 years later. Coincidence?

Eighty years ago this month, the May 1937 issue of Radio News carried an ambitious construction project, this television receiver. TV receivers had been popular projects in earlier radio magazines, but the earlier ones were all mechanical televisions, employing a spinning Nipkow disk.

This set was all electronic, employing a cathode ray tube.  The construction article did not have an individual byline.  Instead, it was attributed only to “the Don Lee Television Staff,” referring to the Los Angeles broadcaster and licensee of W6XAO.

W6XAO image taken off the air.

The plans for this set were also included in other magazines, and the broadcaster also made it available in kit form.

While the receiver was all electronic, it appears that the camera was still a mechanical device.  A spinning disk was used to produce a flying spot to convert previously filmed footage to a video signal.  Shortly thereafter, the station appears to have adopted an electronic camera.

The set, including both RF and video sections, contained a total of 14 tubes in addition to the CRT.  It did not contain an audio section.  Presumably, accompanying audio was received on a separate radio receiver.