Monthly Archives: July 2020

Jiminy Cricket Endorses Sylvania Tubes: 1940

1940JulyRadioCraft3Jiminy Cricket is no fool, so he endorses Sylvania tubes in this ad shown in the July 1940 issue of Radio Craft. It’s not a magazine ad, but instead a picture of a poster that shops could display. And just to be on the safe side, Jiminy strongly suggests that you should just go ahead and replace all of the tubes while you’re at it, even if they’re still good.

Also shown is a clever business card that probably won’t get thrown away immediately. It’s a disentanglement puzzle, the object of which is to remove the string from the tag without tearing or bending the tag or cutting the string. The photo here isn’t very clear, but it appears to be similar to the puzzle shown in this video.

Those who can’t figure out the puzzle are directed to their nearest Sylvania dealer, where the owner will show how to solve the puzzle, and also solve any radio problems that you might have. And while you’re there, he just might sell you a complete set of tubes to replace the perfectly good ones in the radio at home.

In the past, in lieu of business cards, I’ve used things such as customized rulers, promotional calendars, and wooden nickels.  A puzzle made out of cardboard and string probably doesn’t have a lot of staying power, but it will probably get looked at.



USS Indianapolis

Front page story announcing ship's loss, Chicago Tribune, Aug 15 1945.

Front page story announcing ship’s loss, Chicago Tribune, Aug 15 1945.

Today marks the 75th anniversary of the greatest loss of life in American Naval history, the sinking of the U.S.S. Indianapolis on July 30, 1945. On July 16, the Indianapolis left San Francisco with the enriched uranium which would be used in the Hiroshima atomic bomb. She reached Pearl Harbor on July 19 and raced on to Tinian with the cargo, where she arrived on July 26. After delivering this top secret cargo, the ship continued to Guam and then Leyte, where the crew was to receive training.

USS Indianapolis in 1937. Wikipedia photo.

USS Indianapolis in 1937. Wikipedia photo.

Shortly after midnight on July 30, she was struck by two Japanese torpedoes, sinking in minutes. About 300 of the 1196 crewmen went down with the ship. The remainder were set adrift with few lifeboats and many without life jackets.

Due to radio silence and general miscommunication, the ship was not missed when its scheduled arrival time passed. The 880 men drifted forgotten. Most perished from exposure and dehydration, although the attack is most famous for the sharks the men had to contend with. Undoubtedly, some of the men were killed by sharks, but it is more likely that most of the victims succumbed to exposure and dehydration, with the dead being consumed by sharks.

The men were discovered by accident three and a half days later when Lt. Wilbur “Chuck” Gwinn and Lt. Warren Colwell spotted the men adrift during a routine patrol fight.

Only 317 men ultimately survived. Over 800 men lost their lives.

Ironically, the disaster was not reported by the newspapers until August 15.  The greatest naval disaster in American history was decidedly a less important news story that day, since the papers also reported Japan’s surrender and the end of the war.

Of interest to radio amateurs is the recreation of the ship’s radio installation (whose call letters were NABD) at the USS Indianapolis Memorial.

References

History at USSIndianapolis.org

 



Sentinel Postwar Portable

1945July30BCIn the final months of the war, American companies knew that they would soon have the ability to produce consumer products, and that there would be a huge pent-up demand for them. Most of them, like Sentinel Radio Corp. of Evanston, Illinois, were planning for that day. Shown here is that company’s vision for what it would produce after the war, a miniature portable that would fit in a vest or shirt pocket or handbag. Smaller than the smallest camera, it was several times smaller than the smallest prewar set.

This model would use a hearing-aid style earpiece, and that wire would double as the antenna. The whole set, including batteries and tubes, would be little larger than the ubiquitous cigarette case.

This teaser appeared 75 years ago today in the July 30, 1945, issue of Broadcasting. The magazine noted that the company was still engaged in war production and wasn’t able to say for sure when the new set would be available. But the new set had passed preliminary tests, and they hoped to start production the moment restrictions were lifted.



Science Fair Idea: Magnetic Field from Static Electricity

1940JulyPS1For the young scientist who wants to outsmart the science teacher, here’s an excellent science fair project that duplicates the work of American physicist Henry Rowland.

Your teacher undoubtedly knows that a an electrical current generates a magnetic field. But what your teacher probably doesn’t know is that a moving charge of static electricity also generates a magnetic field. This can be demonstrated from this experiment in the July 1940 issue of Popular Science.

To do the experiment, you set up an electric motor as shown here. You attach a disk of hard rubber, which you electrify by rubbing it with a woolen cloth. (Instead of the rubber disk, you can use an old phonograph record. If you don’t know what that is, you can ask your grandparents, or read some of our posts about the history of the phonograph).

Once the disk is charged up, you turn on the motor. As soon as it starts spinning, a compass placed nearby will deflect, showing the presence of the magnetic field.



Heathkit Mohican Shortwave Receiver

1960EI6Seventy-five years ago this month, the July 1960 issue of Electronics Illustrated reviewed the then-new Mohican shortwave receiver from Heathkit. The reviewer reported that the assembled the $100 receiver in about 40 hours, and the result was an astonishingly “hot” 10-transistor superheterodyne that covered 560 kHz to 30 MHz (with apologies, apparently, to the stations at the very bottom of the broadcast dial).

The general coverage receiver would serve the SWL well, and the set was also a good backup receiver for the ham, especially on the lower bands. The bandspread dial was calibrated for the amateur bands, making it particularly useful. The receiver ran on flashlight batteries, but an AC power supply was available for an additional $9.95.

The set weighed in at 17 pounds, making it “transportable” rather than “portable” according to the reviewer.



Radio Control Fishing Boat

1960JulyEE5I’m not sure this is legal everywhere, so check your local fish and game laws before you give it a try. But apparently, it was legal in California in 1960, as shown by the experience of George Boling, W6NOD.  He rigged up this radio controlled boat to pull in the big fish.  The motor and rudder are initially locked, and the remote control, running two watts, allowed him to control the rudder.  The boat trolls, and when a fish bites, the tension slowly winds in the reel, and the motor speed increases slightly.  When the fish is hooked, he steered the boat to shore.

The picture and description appeared in the July 1960 issue of Electronics Illustrated.

 



Potsdam Declaration

Today marks the 75 anniversary of the Potsdam declaration of July 26, 1945.  The proclamation by the Americans, British, and Chinese, laid out the terms for Japanese surrender, the alternative being prompt and utter destruction.

The declaration was never sent via diplomatic channels, but within hours, it was sent in English by shortwave, and shortly thereafter, the Japanese translation was broadcast.  In addition, over three million leaflets containing the text of the declaration were dropped over Japan by American bombers.

The stations broadcasting the message included KSAI on Saipan, whose 50,000 watt signal on 1010 kHz blanketed the home islands as strong as any Japanese station.  Within days, leaflets specifically mentioning Hiroshima and Nagasaki were dropped, warning civilians to evacuate those locations.



Science Fair Idea: Remote Fire Extinguisher

1940JulyPS3If Junior decides to do this science fair project from the the July 1940 issue of Popular Science, he should probably change the name. The magazine calls this gadget a carbon dioxide “gun,” and he’ll probably get in a lot of trouble if he calls it a gun. If he calls it a “remote fire extinguisher,” he’ll probably get a blue ribbon instead of a visit to the police station.

Like all young men like to do, the two shown here are playing with fire, but making a scientific point in the process. In this William Tell stunt, one young man has a candle on top of his head. The other one puts it out with the Carbon Dioxide Gun–er, I mean remote fire extinguisher. Whatever it’s called, the device is simply a can with a balloon stretched over one end. Inside, a piece of dry ice is placed. When the balloon drum is tapped, an invisible cloud of CO2 is expelled, which causes the flame to be deprived of oxygen.



Making Use of Outdoor Spaces for Learning

During the current public health emergency, it is important that to the extent humanly possible, everyone should maintain social distancing from everyone other than their own household.  Therefore, most traditional live educational activities cannot be done safely at this time.

I’m not a doctor, but to me the evidence seems obvious that in most cases, the main problem is indoor gatherings.  This New York Times article, for example, discusses the issue, and this WebMD article, discusses the possible role that building air conditioning systems might play in the spread of COVID-19.  Being outdoors does not completely eliminate the possibility of the spread of coronavirus.  But it seems like common sense that it’s a lot safer being outside than being inside a building with other people.  The CDC’s recommendation is that “in many areas, people can visit parks, trails, and open spaces as a way to relieve stress, get some fresh air, and stay active.”

I believe that the use of outdoor spaces is an excellent way to re-start many activities that have been put on hold. For example, I believe that schools should seriously consider the use of outdoor spaces for classrooms. You can read more about that idea at the website of
Green Schoolyards AmericaThis New York Times article shows how outdoor learning spaces were used by schools during earlier public health emergencies.

Unfortunately, even though some students thrive with distance learning, not all of them do. Whether it’s because of their family situation, a poor internet connection, or just because it’s not their learning style, many students are falling behind both socially and educationally due to the lack of in-person schooling. The use of outdoor spaces can provide these students with a safe place for their education to continue and help stop a new achievement gap.

Similarly, the CDC recommends that communities of faith should consider holding their services outdoors.

I believe the outdoors is a suitable venue for many in-person activities that have otherwise been put on hold.  After months of being isolated, it can be refreshing to see colleagues in person, even if they’re behind a mask and six feet away.

Since I’m in the business of presenting educational programs (namely, continuing legal education programs for attorneys), I decided to take the initiative and see whether my programs could be done outside, so I went ahead and scheduled one in a nearby city park.   I wanted to start with a small group, so I advertised by e-mail to only about 20 attorneys who live in the general area.  The response rate was actually higher than usual, and three attorneys sent an RSVP that they would be attending.  Since I wanted the initial group to be small, I didn’t advertise any further.

I asked all of the attendees to either bring their own chair, or plan to sit on the ground.  The program was paperless.  Ordinarily, I would print the course materials, and there would be a sign-in sheet.  Instead, the course materials were downloaded from the web, and I took attendance at the beginning of the program.  In the course description, I outlined the physical distancing guidelines.

There were a few bugs (including a few literal ones), but overall, I don’t see why larger events can’t be done outside.   The weather was perfect.  It was a sunny day, but as you can see from the photo above, we were able to sit in the shade.  Obviously, this won’t work as well in January in Minnesota, but for much of the year, the weather is suitable.  I announced that this program was going to take place rain or shine, and I don’t think rain would have been much of an issue, if attendees simply brought an umbrella or raincoat.

I did learn a few lessons:

  • Face masks make it harder for people to hear.  I started the program wearing a mask, and I asked whether it made it difficult for them to hear me, and they said that it did.  Since I was standing more than 20 feet away, we decided that it would be best for me to speak without a mask.
  • If we had a larger crowd, it would have been advisable to have a sound system.  In an indoor setting, I can easily speak to 20 or 30 people without a PA system.  But outdoors, my voice doesn’t carry as well, particularly when airplanes fly over or trucks drive by.   Also, if any of the speakers are wearing a mask, the sound system is even more important.
  • Some planning does need to be done for seating.  One attendee didn’t bring a chair and instead sat on the ground.  Apparently, there were enough ants in the park that he had to stand up after 45 minutes.

The outdoor air is not a magic bullet that kills germs.  However, it seems to me that an outdoor location is much safer than corresponding indoor spaces.  At this time, it ‘s probably not safe to go back to business as usual with respect to things such as education and business.  But it seems to me that creative use of outdoor spaces will bring us much closer to normal than we would be able to do with virtual gatherings alone.

In education, for example, some kids simply require in-person instruction.  Some of them thrive learning online, and that’s great.  But I think even occasional in-person sessions might make a huge difference for some kids.  If it’s too risky for them to have their math or English class in a traditional classroom, then it seems to me that educators should at least consider the idea of having those classes outside.

For distance learning, technology is required.  But for outdoor learning, very little technology is necessary.  As my experience shows, a small public address system would be useful.  But other than that, little more than chairs, desks, and a blackboard are required.  If there’s a video to be watched, then the students can watch it at home.  But it seems to me that many kids need some attention where things can be explained in person, so that the teacher has in-person feedback of whether they’re being understood.  That doesn’t require a building–it merely requires a space, and in most cases, an outdoor space will serve the purpose.

I’ll be doing future programs outdoors, and it seems to me that many activities that are normally done indoors, such as meeting with clients, can be safely conducted outdoors.  As the weather gets cooler, being outdoors will be less suitable.  Therefore, some of my future programs will be in a drive-in format where participants can listen on their car radios.



CB Channel 9

1970JulyPEToday marks the 50th anniversary of the designation of CB channel 9 for emergency use only, July 24, 1970. This announcement appeared in the July 1970 issue of Popular Electronics.