Monthly Archives: May 2024

Operating a Landline Telegraph

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441500216_10232620648842474_8600482236910331051_nThis weekend, I had the pleasure of demonstrating a landline telegraph to a group of scouts at the BSA Northern Star Council Spring Camporee at Stearns Scout Camp near South Haven, MN.  Over 500 scouts attended, and the theme of the event was American Heroes.  The event included a group of Civil War reenactors from the New Ulm Battery, complete with their cannon.  Since the telegraph shaped the Civil War, we were placed near them.  The two awnings here, about 100 feet apart, were separate telegraph stations, with the line connecting them run through the tall grass.

We showed the scouts the telegraph in action, and let them hear what it would have sounded like during the Civil War.  I don’t know the exact age of the instruments we used, but they were probably at least a hundred years old.  They were purchased on eBay by another scout leader who got them working.

Since I am not able to copy the clicks and clacks of a landline telegraph sounder, we also hooked in a beeper.  With that in place, I asked the scouts to send their name, and to their amazement, I copied it correctly.

CodeChartThe purpose of a telegraph is two-way communications, so I gave them a pencil and paper and told them I was going to send them a message.  According to conventional wisdom, you need to memorize the code before you can start receiving it.  But these scouts, and other guinea pigs I’ve experimented on in the past, prove that this is not true.  I printed up copies of the simple chart from LearnMorseCode.com shown here.  It might be gimmicky, but it works.  You place your finger or pencil at the spot marked “start.”  Moving down the chart, if you hear a dash, you go to the left.  If you hear a dot, you go to the right.  When you are done, you are pointing at the letter in question.  I encouraged the scouts to write down the dots and dashes, and then use the chart when they were done.  But many of them were able to do it in real time.  I found that people (young people, at least) can learn the code very quickly using this method, without having to memorize it first.  After hearing a letter just a few times, they get it without bothering to look at the chart.

CipherWheelThe round object shown in the top photo is a reproduction U.S. Army cipher wheel.  Not unlike a typical secret decoder ring, this replica is available on Amazon and is nicely crafted.  (If you want to download and print a similar one, you can do so here.)   You can read more about how it was used at this link.  It was apparently used mostly for messages sent by flag, but it could be used for telegraph messages as well.  Most of the letters are represented with numbers containing 1’s and 8’s.  But the 8’s are really 2’s.  Eights are  used only because they are easier to read on the circular rule.  When used on the telegraph, the “dot code” was often used, as it permitted minimally skilled operators to use the telegraph.  So if A=1221 in that day’s code, then the letter could be sent by sending one dot, two dots, two dots, and one dot.

 

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1954 Civil Defense Radio Truck

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Screenshot 2024-05-02 8.34.56 AMScreenshot 2024-05-02 8.36.16 AMShown above is the 1939 Studebaker employed in 1954 by the City of Malden, Mass., as its mobile emergency communications center. Shown at left are Sgt. Orin Hood, W1LD, of the Malden Police Department, along with Eli Nannis, W1HKG, the city’s radio officer and emergency coordinator.

The photos and description appeared 70 years ago this month in the May 1954 issue of Radio Electronics, which explained how such a station could be set up on a reasonable budget. The Studebaker patrol wagon was about to be surplussed by the police department. It had been rarely used, and was in good condition.

The City was also going to get rid of a 1800-watt gasoline generator, and it was obtained and placed on a two-wheel trailer.

For radio equipment, it was equipped with a Harvey Wells model TBS-50C transmitter and National NC-183 receiver. As a backup station, the truck was equipped with a 10-watt 10 meter transmitter, and a car radio and converter. That station could run off the truck batteries. The truck also contained a radio for police frequencies, as well as telephones and wire for hooking them up as needed.

The station had already been put into service when tornadoes struck nearby Worcester.



1944 One Tube Receiver

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1944MayRadioCraftEighty years ago this month, the May 1944 issue of Radio Craft carried this circuit for a one-tube receiver. It had been sent in to the magazine by one Bob Smith of Montclair, NJ, who pointed out that standard plug-in coils could cover the shortwave and broadcast bands. He added one word of caution, “do not ground set.” This, of course, is because it was running straight off the AC line, and if you grounded it, there would be a 50/50 chance that you would short out the power. We, of course, will add another word of caution, namely, not to touch anything. The headphones are hot, strapped right to your head. So if you touch a grounded object nearby, there’s a 50/50 chance that the resulting current would run right through you.

A 70-watt lightbulb is used to drop the filament voltage to 12.5 volts to light the filament of the 12A7 tetrode/diode tube.



Crystal Sets for the Poor and Needy, 1924

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1924May16WashA hundred years ago today, the May 16, 1924 issue of the Washington Star carried this item. Many listeners had graduated to tube sets, and radio executive Le Roy Mark wanted to see to it that their old crystal sets made it into the hands of the poor and needy of Washington. He had begun an ongoing campaign to collect old crystal sets at Piggly Wiggly and Peoples Drug stores in the District, from whence they would make it into the hands of the needy. 400 names had already been collected, but Mark requested that clergymen and physicians send him the names of others who might benefit.

The Boy Scouts of the District had volunteered to install the sets. The only expense would be the cost of antenna wire, and contributions were being solicited for that purpose.

According to his 1938 obituary, Mark was a pioneer of radio broadcasting in Washington, as well as the insurance industry. The obituary still remembered him as “a leader in the campaign to provide funds to furnish radio sets to all shut-ins, particularly to make available a sufficient number of sets to enable all hospitalized World War veterans to listen to radio programs.”



1939 Shortwave Broadcasting

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1939LifeMay15a1939LifeMay15bEighty-five years ago, all of the countries that would soon be at war were gearing up for the inevitable propaganda battles, and the May 15, 1939, issue of Life magazine explained some of the technical issues involved. The Germans had an advantage when it came to broadcasting to South America, since their beam could be only half the width required by the Americans to cover the major population centers.

But as far as broadcasting to the respective homelands, the Americans had the advantage. They could blanket Europe with a narrow beam, whereas the signal from Berlin would need to be extremely wide to cover all of the United States.



1939 Portable Radios

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1939MayRadioTodayThis gentleman’s technique with the canoe paddle leaves something to be desired, but his girl doesn’t even notice, because she is enthralled with the portable radio he had the foresight to bring along on their date.

Eighty-five years ago, portable radios were a hot commodity, and the May 1939 issue of Radio Today carried some pointers for selling them. In addition to the normal ideas of direct mail, window displays, etc., it suggested some other ideas. For example, it recommended to “have a clown or a fairy-story character carry a battery-operated radio playing around the streets, with appropriate signs. Thousands of people don’t yet know there is such a radio.” If the clown didn’t work out, the magazine suggested having a man with a battery-operated portable meet all he trains, or lending a radio to prominent people in the community and taking their picture.



1944 British Car Radio Installation

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Screenshot 2024-04-25 11.39.45 AMEighty years ago, somewhat to the surprise of many in the industry, the British government lifted the sartime ban on radio receivers installed in cars. This was welcome news to those who still drove a car for essential purposes. And it meant that the price of secondhand auto radios in dealer’s stocks suddenly increased in price.

Because both automobile and radio dealers were swamped with work, it probably meant that the owner of a car who wanted a radio installed would need to do it himself. This, the May 1944 issue of Practical Wireless contained an article outlining the basics. The car radio installation shown above appeared on this issue’s cover.

The magazine did stress the need for a license.  The license for the receiver in your home would not cover the additional set in your car, and you would need to secure a license at the post office before tackling the installation.



1964 Radio Control Truck

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1964MayEISixty years ago this month, the cover of the May 1964 issue of Electronics Illustrated shows Dad putting the finishing touches on this remote-control vehicle that he’ll be surprising Junior with. The transmitter puts out 100 mW on CB channel 23 for good range without the need for a license. One push of the button steers the truck to the right as long as the button is held down, and two pushes steers it to the left.

The editors couldn’t find any vehicles with steerable front wheels, so they bought the Tonka truck shown here and modified it by adding a steerable front axle.

Complete circuits for transmitter and receiver are included. The receiver employs five transistors, and the transmitter, three.



1924 One Tube Broadcast Receiver

1924MayBLA hundred years ago this month, the May 1924 issue of Boys’ Life showed scouts how to put together this one tube broadcast receiver. The design was the winner of a contest put on by the magazine as the very best one-tube receiver. The winner was C.H. Brown of Edgewood, Maryland.

The magazine noted that the set was not regenerative. That was good, in that it wouldn’t break into a squeal to the consternation of listeners living nearby. It could be used for ‘phone signals, modulated CW, and spark transmissions. It was, however, no good for those newfangled CW signals that were showing up on the air.

A number of tubes could be used in the set, such as a UV-199, C-299, UV-201A, or C-301A. The set used a reflex design, meaning that the tube had two functions. It first amplified the incoming RF signal, which was then detected by a crystal detector. It was then fed back to the same tube which amplified the audio. This design accounted for the extraordinary distance and volume of which the set was capable.

Total cost was said to be about $18.00.

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