Author Archives: clem.law@usa.net

1896 Phonograph “Concert”

1919MayTalkingMachineWorldToday, we take a nostalgic look back a hundred years to the May 1919 issue of Talking Machine World, which was itself taking a nostalgic look back 23 years to 1896.

The magazine reproduced this poster advertising a “concert” at the Methodist Church in Chagrin Falls, Ohio. The benefit event (with admission of either 10 or 20 cents) featured Edison’s Most Wonderful Invention, namely the phonograph. The poster pointed out that the device would reproduce “the human voice, bands, whistling, etc., etc.” And this was not some puny device that could be heard only through an ear tube. The phonograph was one which could be heard by hundreds at the same time. The concert included a recording of the chimes “by the Bells in St. John’s Cathedral,” although it’s not clear which church of that name is being referenced.

The concert was to take place at 7:30 on February 14, 1896.  The current United Methodist Church of Chagrin Falls traces its roots back to the 1830s, and reports that it built on its current site in 1884.  So it appears that the concert took place at that church’s current location of 20 S. Franklin St.

At the beginning of the 20th century, phonographs rapidly became common.  Even before most people owned one, they had an opportunity to listen.  But in 1896, the instrument was still quite a novelty, and it’s likely that most Americans had never heard one.  So it was probably well worth a dime or two to go listen to a concert featuring the greatest invention of the century.



1959 Two Transistor Portable

1959MayPM1Sixty years ago this month, the May 1959 issue of Popular Mechanics showed how to put together this two transistor receiver. While within the capabilities of the beginner, the set was a good performer. According to the article, the set was capable of pulling in stations 10-15 miles away with only the built-in antenna.

The RF amplification was handled by a 2N168A transistor. It operated as a regenerative amplifier, with a 1N66 diode serving as detector. The audio was then fed back to the same transistor, which was “reflexed” to serve as the first AF stage. A 2N170 transistor served as a second stage of audio amplification to drive the high-impedance earphone. The set was powered by four penlite cells wired in series.

1959MayPM2



Electronics Quiz from 1959

1959MayPEquizSixty years ago this month, the May 1959 issue of Popular Electronics contained these electronic brain teasers. We’re confident that most of our readers can figure them out, but just in case, we’ll show the answers tomorrow.

If you need a larger version, from most browsers, click twice on the image above.



Science Fair Idea: Does a Flame Conduct Electricity?

1939MayPSIf Junior’s science fair project is due tomorrow, there’s still time to whip together a meaningful project, and this one from the May 1939 issue of Popular Science should fill the bill. You probably have all of the necessary parts at home. If you don’t, you should be able to find them at the trusty dollar store.

This experiment answers the question, “does a flame conduct electricity?” It turns out that it does, and this experiment proves it. All Junior needs (in addition to the obligatory poster board and magic markers) is a battery (a 9-volt battery should work fine), a pair of headphones (a cheap pair of stereo earbuds will do the trick), a few short pieces of wire, and a candle.  And, of course, don’t forget to give Junior some matches or a lighter!

One terminal of the battery is hooked to the headphones. The other terminal of the battery and the other terminal of the headphones are each hooked to a piece of wire. Remove the insulation for the other end of those two wires. When Junior sticks the two wires into the flame of the candle, a clicking will be heard in the headphones, confirming that electrical current is flowing.

If Junior has more time to prepare his entry, he might want to consider more complex versions, such as the flame audion or the flame speaker.

1939MayPS2If you don’t trust Junior with matches, then the same magazine also shows the experiment shown here.  Junior will need a piece of glass, an iron, a lamp (with an old-fashioned incandescent light bulb) and a thermometer.  The glass will effectively block the heat from the iron.  The radiant heat from the lamp, however, has a shorter wavelength and will pass through the glass.  So when the iron is used, the thermometer won’t budge.  But with the lamp, the temperature will rise quickly.



1944 Car Tune-Up

1944May5MilJourA few weeks ago, we showed a snapshot of wartime grocery prices. Today, we show how much it cost to have your auto serviced 75 years ago. This ad appeared in the Milwaukee Journal on May 5, 1944.

Because of gasoline and tire shortages, it’s likely that most cars spent most of the war parked.  But even if they got little mileage, they would need occasional service.  And Sears Roebuck was there to help, with its Milwaukee service stations open until 9:00 every night except Sunday at 1337 W. Forest Home Ave. and 2100 W. North Ave.

A tune-up was $2.39 and included cleaning and inspecting the distributor, testing the coil condenser caps, and checking the spark plug wires for breakdown.  The spark plugs would be cleaned and the gap checked.

In addition, the service included inspection of the fuel pump and adjusting the carburetor.  The battery would be cleaned and refilled, and the generator, fan belt, and radiator would be inspected.

 



1969 Two Tube Superhet/Regen

1969MayEE1Fifty years ago this month, the May-June 1969 issue of Elementary Electronics showed how to put together this two-tube receiver. The set covered 1.7-30 MHz with plug-in coils. And despite having only two tubes, it had excellent performance thanks to its design, which combined a superheterodyne and regenerative receiver.

The set used two dual tubes. A 6CQ8 served as mixer and IF amplifier, with a 12AT7 serving as regenerative detector and audio amplifier. The power supply consisted of transformer and solid-state diode.

1969MayEEschematic



1934 Two Tube Regenerative Shortwave Receiver

1934MaySWcraft

This handsome little two-tube shortwave receiver is described in the May 1934 issue of Short Wave Craft magazine. The circuit was designed by the National Radio Distributing Co., which presumably had all of the parts for sale, and used two type 30 tubes. A 45-volt B battery was sufficient for normal reception, but to pull in the weak signals, it was recommended to use 90 volts for the amplifier stage. In addition to the tuning dial, two other controls were visible on the front panel. One was a variable capacitor for adjusting regeneration, and the other was a rheostat for setting the filament voltage.

A well-insulated antenna of 45-100 feet was recommended.

1934MaySWcraftSchematic



Eico 720 Transmitter, 1959

1959MayEISixty years ago this month, the May 1959 issue of Electronics Illustrated carried a review for the then-new Eico 720 transmitter.

The reviewer noted that the kit could be assembled in a week of evenings, and was within the capabilities of the beginning kit builder. The set had a maximum input power of 90 watts, but the plate current meter had a red line indicating the 75 watt limit for novices, the kit’s primary market. The review noted that the transmitter ran cool, despite its compact size. The output filtering was especially lauded, as the transmitter was well protected against television interference.

The kit sold for $79.95, with the wired version selling for $119.95. The review concluded by declaring the 720 a Good Buy for either the novice or the veteran ham.

For a look at a remarkably well preserved specimen, see this link.



Dr. W. Eberle Thompson: Abolitionist, Underground Railroad Conductor, Doctor, Radio Fan

1939MayRuralRadioShown here is Dr. William Eberle Thompson of Bethel, Ohio. The 104-year-old doctor is wearing headphones and listening to WLW radio. The photo was taken on the occasion of an interview by Ed Mason, WLW Farm Events Announcer, who wrote about the interview in the May 1939 issue of Rural Radio magazine. Mason noted that he “interviews some mighty interesting and important people. But never have I talked to anyone who could match this country doctor who voted twice for Lincoln.”

While the magazine article is lacking in details, the centenarian doctor is almost certainly the same person described in the book The Underground Railroad: An Encyclopedia of People, Places, and Operations. In addition to merely voting for Lincoln, Dr. Thompson played a much greater role in ending slavery. “In his youth, the family’s two-story brick residence at 133 South Main Street was a safehouse. In adulthood, his home and office at 213 East Plane Street received refugees.” The Rural Radio article mentions that Dr. Thompson’s “hands and eyes, now weary from service to his neighbors, had brought him fame as a crack shot with his old muzzle-loading rifle.” The old muzzle loader had been put to good use, since “to secure slaves in flight from posses, Thompson shot their bloodhounds.”

According to this site, Dr. Thompson became an active member of the Bethel Underground Railroad network as a teen. He guided fugitives from Bethel to the Elklick area near Williamsburg. He practiced medicine in the community for eight decades and was active in village government and social affairs.

The headphones in the photo were a gift, as explained in the magazine article:

Long after the switch had been turned which took us off the air, we talked. I learned that he liked to listen to the radio, and especially news broadcasts, but his hearing had failed and he had not used his radio for several years.

When Phil Underwood, WLW engineer, heard this, he opened that magic box that a radio engineer always carries. He brought out headphones, special amplifiers, wires and switches. When we left, Dr. Thompson was sitting by his radio hearing distinctly for the first time in years hearing news by the magic of radio.

The Rural Radio article refers to the doctor as  “C.  Eberle Thompson.”  This is almost certainly an error, since it’s unlikely that there was another centenarian doctor in the same small town.    Dr. Thompson died in 1940, a few months shy of his 105th birthday.  He continued to practice medicine until about a month before his death.