1921 Alarm Clock Extension

1921JanPMclock

1921Jan4BdjiPioneerAs you can see from the ad at the left, an alarm clock was a non-trivial expense a hundred years ago. This store, the the Given Hardware Company, 316-318 Minnesota Avenue, Bemidji, Minnesota, had models ranging in price from $2.00 to $5.75. That doesn’t sound like a lot of money, but according to this inflation calculator, that works out to a range of $28.92 to $83.14 in today’s money. If you had a clock in one room and wanted to hear the alarm in another room, going out and buying a new one would constitute an unnecessary expense.

You can compare that price to some of the perfectly functional, extremely accurate clocks below, all of which are probably orders of magnitude better than the 1921 model:

In fact, you can probably get a perfectly suitable alarm clock at the closest dollar store. So if you need an alarm clock in another room, or need a louder alarm clock, it’s a simple matter of going to the store or going to Amazon and just buying one.

But a hundred years ago, it was a problem best solved by ingenuity, as shown by the self-explanatory idea shown above. This relied on the fact that the glass of most alarm clocks could be rotated, but would still hold its position. Therefore, a small hole was drilled in the glass and a machine screw was carefully inserted so that it would contact the hour hand, but not interfere with the minute hand. A small piece of spring brass wire was soldered to the hour hand to serve as a brush and make contact. The alarm could be set to any desired time simply by revolving the glass.

In case you’re wondering how much the doorbell cost, this 1918 Western Electric catalog showed them starting for about $1.30, and the dry cell battery was about 60 cents.

This idea appeared in the January, 1928, issue of Popular Science, and had been sent in to the magazine by one G.H. Rouse. The ad appeared in the Bemidji Daily Pioneer, January 4, 1921.



1921 Printing Radiotelegraph

1921JanPScodereaderThis gentleman, shown in the January, 1921, issue of Popular Science, wasn’t a QRQ operator, but he was still able to copy even the fastest radiotelegraph stations thanks to this device developed by William G. Finch of Buffalo, New York.  Instead of the familiar buzz in the headphones, the code was rendered as dots and dashes printed on paper tape, which could be read at the operator’s leisure.  The device employed an ultra-sensitive relay along with an “ordinary printing telegraph machine.”

The “ordinary printing telegraph machine” had actually been around for quite some time, since the first telegraphs were designed to print the dots and dashes, rather than be copied aurally.  It was later discovered that the operators could hear the letters as they came in, and that became the norm.



Science Fair Idea: Barkhausen Effect

1941JanRadioTV2The young scientist wishing to create a simple but spectacular science fair project is almost assured of taking home the blue ribbon by duplicating the 1919 experiment of German scientist Heinrich Barkhausen establishing the domain theory of magnetism. When a piece of ferrous material is magnetized, it does not magnetize evenly. Instead, tiny pieces of material are magnetized together in discrete pieces. This is known as the Barkhausen effect.

Stamp Heinrich Barkhausen.jpg

Barkhausen on 1981 East German stamp. Wikipedia image.

To prove this, a coil is wrapped around a piece of iron, and the coil is connected to the input of an audio amplifier. As a magnet is brought toward the coil, static is heard in the speaker. But if the iron core is removed and the experiment repeated, the static is absent. A simulation of the effect can be found at this link.

Replica of Barkhausen’s experiment. Wikipedia photo.

Full instructions can be found in the January 1941 issue of Radio & Television magazine. You will need 38 gauge or smaller enamel wire to wind the coil, as well as an audio amplifier and speaker.

 



Ernest Sperling, 9BBF, W9BKX

1921Jan26NewUlmThis article appeared a hundred years ago today, in the January 26, 1921 issue of the New Ulm (MN) Review.

HEARS CONCERTS OVER WIRELESS

ERNST SPERLING LISTENS TO MUSIC PRODUCED IN MASSACHUSSETS

TONAL QUALITY AS GOOD AS IF RENDERED IN SAME ROOM HE SAYS

Listening to a high class phonograph concert being rendered in far off Massachusetts while comfortably seated your New Ulm home is one of the joys of life not accorded to all of our citizens, but one of our well-known young men enjoys this entertainment frequently, sometimes twice and three times a week. This young man is Ernst Sperling, son of Prof. and Mrs. J. E. Sperling, who has a modernly a completely equipped wireless telegraph apparatus installed the home of his parents on [21] South Jefferson street.

Special Apparatus Needed.

A special apparatus, known as the audion receiving set, is necessary to receive music by wireless. This apparatus is more sensitive and of a better grade than the regular wireless receiving instrument. There is very little electrical energy used in transmitting music waves by wireless, so that the detector must be unusually sensitive, or the other tones will not be clear. Another important factor in the transmission of music via wireless is the prevailing weather conditions. If the air is clear and quiet, with no perceptible wind, the music is much more audible and there is no rising or falling of the tone During a wind that is strong enough to sway the antenna the music sounds as if it were being played on a phonograph, the modultor of which is being changed constantly.

News Every Night.

Mr. Sperling spends a considerable part of his spare time evenings at his wireless instrument and receives many messages containing accounts of important happenings not only in this country but abroad also. One of the principal sources of this in formation is the big wireless station on Arlington Heights, near Washington, D. C., from which such messages are sent out every evening. He also receives messages from commercial stations every section of the United States, the most distant one being located in Alaska.

“Connect” With Europe.

Mr Sperling is at present working on a large receiving set, which, when completed, will enable him to get wireless messages direct from Europe, thus enlarging the scope of his wire less work. Quite a number of interested New Ulmites have visited the Sperling home to view the young man’s wireless apparatus and have him explain its workings.

Later in the year, the newspaper’s June 1, 1921, edition reported that young Mr. Sperling had agreed to supply farm market reports to the telephone company, which made them available to local farmers.

Sperling is listed in the 1922 callbook as being licensed as 9BBF (with his name spelled Ernest). His father, Prof. J.E. Sperling of Dr. Martin Luther College is listed in this yearbook as a Pastor Emeritus of the Joint Wisconsin Synod of the Lutheran Church.

In the 1937 callbook, Ernest is listed as one of two licensees, along with one Victor H. Schleuder, as licensee of W9BKX of 313 S. State St., New Ulm. He is listed in the 1940 census as living at 21 South Franklin.

 



Print Your Own Postcards: 1951

1941JanRadioRetailingA80 years ago, the small retailer, such as a radio dealer, would probably find this to be a very economical way to advertise. For $8.50, he would get everything necessary to print postcards himself, and then he could mail them out for one cent.

The device is a small mimeograph, or stencil duplicator.  The mimeograph should not be confused with the spirit duplicator, or ditto machine, although it often is.  The mimeograph used a stencil, a thin membrane which was physically cut by a typewriter without a ribbon.  The ink was forced through the resulting holes, making a very good image.

This inexpensive model was smaller than most, but could print a postcard in much the same way that one would use a rubber stamp.

If you’re looking for another antique method of printing, check out my hectograph page.

The ad appeared 70 years ago this month in Radio Retailing magazine, January 1951



1951 Arvin Model 4162 CM Console TV

1951JanRadioTVRetailingThis ad for Arvin Television appeared seventy years ago this month in the January 1951 issue of Radio & Television Retailing.

It highlights their top-of-the-line console, the 16 inch model 4162 CM, which retailed for $349.95 (or an extra $20 for a blond cabinet), plus federal excise tax and warranty. Other sets started at $129.95, and the ad reminded dealers that the company had America’s most complete radio line, starting at $15.95, all of which rolled off the assembly line of Arvin Industries, Inc., of Columbus, Indiana.



1946 Radio Listings

1946Jan23WashEveStarIf you had tuned in on the radio in Washington 75 years ago today, January 23, 1946, here is what you would have heard, according to that evening’s edition of the Washington Evening Star.



1971 Two Transistor Transmitter

1971JanEIFifty years ago this month, the January 1971 issue of Electronics Illustrated carried the plans for this transistorized CW transmitter for 40 and 80 meters. The magazine noted that even though transistors had caught on for many electronic applications, tubes were still the most common for transmitters, due not only to the high cost of RF transistors, but also due to output impedance matching problems.

The design solved these problems by using high voltage transistors originally intended for audio amplifiers running off 117 volts. These allowed high impedance matching with the pi-net antenna tuner that hams were accustomed to.

The transmitter used two RCA 40321 transistors, which still seem to be available as New Old Stock (NOS) items. They were run in parallel as a Colpits oscillator. The heat sinks of the small transistors were mounted to a piece of aluminum mounted below the main chassis, which had holes drilled to allow the transistors to cool.  The transmitter had an input power of 17 watts.

1971JanEI2



Taking Requests by Signal Lamp: 1946

1946Jan21BC

WW2-era signal lamp. Wikipedia photo.

The taking of requests has been a long-standing tradition in the broadcasting industry. Most typically, the requests come in by phone, but other methods are possible, as shown in this item from Broadcasting magazine 75 years ago today, January 21, 1946.

WXLH, the Armed Forces Radio Service station in Okinawa, which had come on the air on May 17, 1945, carried a request program, originally slated to run 45 minutes six nights a week. The program was widely popular with servicemen, and requests poured in by telephone, teletype, mail, and in person.

Awase Mudflat Okinawa.jpg

Buckner Bay. Wikipedia image.

Left out, however, were the sailors on the hundred or more ships anchored in Buckner Bay. To accommodate them, on Christmas, some of the station’s engineers rigged up a 500 watt bulb on a stand and pointed it toward the bay. They blinked out a message that the station would be happy to take Navy requests as well.

The sky lit up within minutes with beams of light crisscrossing the horizon. AFRS and Signal Corps men dotted the hillsides and took down the requests.



1941 Inagural

1941InnaguralParade1941Innagural2Eighty years ago today, NBC Radio covered the third inagural of FDR with the help of a 25 watt FM transmitter. During the parade, receivers atop the Washington Monument and the dome of the Capitol. The pickup at the Washington Monument is pictured here, and clearly features a National HRO receiver not unlike the model we previously showed.

This item appeared in the January 27, 1941, issue of Broadcasting, which also carried the item at left detailing the work of radio amateurs from the Washington Radio Club. The hams handled 509 pieces of traffic for Red Cross first aid teams with battery-powered 2-1/2 meter radios.