Monthly Archives: April 2014

1939 Television: Here at Last and Here to Stay

KresgeTVSeventy-five years ago, television looked like it was ready to take off, but it didn’t become a widespread reality until after the war. There had been experimental transmissions for a few decades, and by 1939, sets were being advertised.  April 30, 1939, marks the day from which TV has been continually broadcast in the United States.

The Newark Sunday Call for that day contains at least three television advertisements. One is this ad for Wilderotter’s, which announces that “television becomes an actuality for the public today!” It announced a special 3-1/2 hour program to be telecast from the World’s Fair by NBC, featuring an address by president Roosevelt. It announces that the store will be open from noon until 1 P.M. on Sunday for the public to hear and see this special program. It also includes the NBC television schedule, which included programming on Wednesday and Friday from 4 P.M. to 9 P.M., “outdoor telecasts of news events” on Wednesday through Friday afternoons, and “film transmissions” on Monday, Tuesday, and Thursday from 11 A.M. to 4 P.M.

The Griffith Piano Company has this ad announcing that it, too was ready to put a television receiver in your home. The advertised prices ranged from $199.50 to $600.

Finally, Kresge’s Department Store announces that television “is here at last–and here to stay!”

Unlike earlier television system, these models were electronic. They used a system similar to postwar television, but were 441 lines. The station, then will the call sign W2XBS, remained on the air only until 1940 or 1941 in the original 441 line format. It received a commercial license in 1941, and became WNBT. But at that time, it began using what is usually call the “postwar” format of 525 lines. Some broadcasting continued during the war, but the station was used mostly by the New York Police Department for civil defense training. The station, now WNBC, does have the distinction of being the nation’s oldest continuously operating TV station.  And it celebrates its 75th birthday on April 30, 2014.

So Kresge’s was correct in saying on April 30, 1939, that television was here to stay. But unfortunately for those who purchased a $600 set in 1939, the device became obsolete in two years with the switch to the 525 line format.



Another 1922 Crystal Set

CrystalSetNewspaper

On this day 92 years ago, The Ashland (Oregon) Weekly Tidings published these instructions for constructing a radio set. As you can see, it’s simply a crystal set. Also shown is a test buzzer, which it describes as being “in reality a miniature radio transmitting station” to test the detector and find the crystal’s sweet spot in the absence of an actual station.

This article bears the dateline of New York, and it’s undoubtedly a news service item that was published in many local papers. The issue also includes a list of broadcast stations in operation. None in Oregon is listed, but there are stations in Seattle, Spokane, Yakima, as well as Los Angeles. The test buzzer would probably be a necessity for the Oregon listener to ensure the radio was ready to pull in one of these distant stations at night.

In this listing, WLAG, the predecessor of WCCO, is not yet listed. Minneapolis is on the map with WLB, the station at the University of Minnesota and predecessor of KUOM.

In retrospect, both of my sets of grandparents were fairly early adopters of radio. My dad’s family had a radio, I’m guessing in the early 1930’s. And I believe this was before the farm was electrified, so this was probably a battery set. My maternal grandfather built an early crystal set, probably about this same time as these plans were published, or shortly thereafter. Unfortunately, I don’t have any details, nor is there any picture of this set. I’m told he took a class during which he built the radio. He knew the trick of placing the headphone in a crystal bowl, which would amplify the sound enough to allow multiple people to listen. Chances are, the sounds of WLB, or perhaps WLAG, were what the assembled group could hear.



Wireless Goes to War: 1914

veracruzflag

The flag being raised at Vera Cruz, 1914. From Wikipedia.

A hundred years ago, the wireless had unquestionably established itself as one of the tools of war. On this day in 1914, the Mexican Port of Veracruz was under American occupation after three days of fierce fighting under the command of Admiral Frank Friday Fletcher.  The invasion was a response to the arrival of arms bound for Mexico City and “El Usurpador”, President Victoriano Huerta, who was subject to a U.S. arms embargo. The arms were originally thought to have been provided by the German government, but actually originated from the Remington Arms Company in the U.S. and had been sourced by American financier John Wesley De Kay.

The episode is an early case of the role that the wireless telegraph was now playing in war. In the early morning hours of April 21, the American Consul in Vera Cruz, William Canada, sent an urgent cable to Washington reporting that the German ship carrying the arms was in the harbor and its arrival was imminent.  The cable reported that approach of the German vessel and the fact that locomotives and cars were ready to rush the arms to Mexico City.  Secretary of State William Jennings Bryan received the cable at 4:00 in the morning and phoned President Wilson’s private secretary, Joseph Tumulty, who decided to awaken the President. Even though the White House servants were reluctant to do so, they agreed and the President came to the telephone.

At the same time, Navy Secretary Josephus Daniels phoned and was put on the same line. Daniels had received a wireless message from Admiral Fletcher that 250 machine guns along with 15 million rounds of ammunition would be landed from the vessel. The President listened in silence until Navy Secretary Daniels asked him “what shall we do?” “Tell Fletcher to seize the customs house” was the President’s reply. A few minutes later, a wireless was dispatched to Fletcher. He received the message at 10:00, and marines were on the ground an hour later.

You can read the wire reports in the Logan (Utah) Republican, where they appeared on April 25, 2014.



An Aeroplane Wedding Via Radio, 1922

RadioWedding

The wedding party (top) and listeners. From the Literary Digest.

92 years ago today, the Washington Herald of April 24, 1922, reports the wedding that same day of Miss Sarah Cockefair and Albert P. Schlafke, both of Brooklyn, N.Y.:

NEW YORK, April 23 – Three hundred thousand radio fans have received cordial invitations to the wedding of Miss Sarah Cockefair, a nurse at the Brooklyn Hospital, and Albert P. Schlafke, of Brooklyn, who will have the ceremony performed in the clouds above Curtiss Flying Field, on Long Island, tomorrow afternoon.

The minister will be Lieut. Melvin W. Maynard, winner of the transcontinental air race, sometimes known as the “Flying Parson,” and the witnesses will be a radio operator and Lieut. Maynard’s mechanician. The guests will include nearly everybody who owns a radio receiving set.

The airplane will take off at Mineola, Long Island, at 2 o’clock. The wedding service will take place immediately afterward, and the bride and bridegroom, with their genuine “sky pilot,” will start for Schenectady and Syracuse on a flying honeymoon.

Sarah Cockefair

This picture of the bride is from the Brooklyn Daily Eagle, April 25, 1922.

The wedding apparently took off without a hitch, and was reported elsewhere, including Aerial Age Weekly and the Literary Digest for May 27, 1922, According to the Brooklyn Daily Eagle,  Mr. Schlafke was the athletic director of the Veterans Mountain Camp at Tupper’s Lake, New York. According to the Literary Digest account, the flight was made under the auspices of the American Legion as part of its campaign on behalf of the proposed Soldiers’ Mountain Home. Flying Parson Lt. Maynard spoke about the home, which would provide care to members suffering from ailments requiring pure mountain air. One of the witnesses was Miss Jeanette Vreeland, who performed a number of vocal solos to the couple and to the radio audience below.

Sadly, there’s a grave in a Brooklyn cemetery for one Sarah Schlafke,who died less than a year later in February 1923. According to the Social Security Death Index, one Albert Schlafke, born on August 21, 1891, with a Social Security Number issued in New York, died in Colorado Springs, Colorado, in 1965.




Herbert Hoover Ponders Deputizing Hams



Radio Fan Getting the Time and Weather Observations Over the Wireless.  It Will Not Be Long Before the Radiophone Will be One of the Necessities of the Home.  Richmond Times-Dispatch, April 23, 1922, page 3.

Radio Fan Getting the Time and Weather Observations Over the Wireless. It Will Not Be Long Before the Radiophone Will be One of the Necessities of the Home. Richmond Times-Dispatch, April 23, 1922, page 3.

92 years ago today, the Richmond Times-Dispatch of April 23, 1922, reported the possibility that amateur radio operators would serve as deputies of the Commerce Department in policing the airwaves. The paper reports that Commerce Secretary Herbert Hoover was favorably disposed to a recommendation that deputy radio inspectors be elected from the ranks of hams.  Once deputized, these inspectors would endeavor to secure strict observance of the radio communications laws.  If the law required compensation, then these deputies would serve for a payment of one dollar per year.

The paper pointed out that hams in the Richmond area had already voluntarily observed for a number of years rules of etiquette. For example, in Richmond, local stations had been observing a schedule described thus:

the hours from 6 A.M. to 6 P.M. as “free air,” that is, communications of any kind; 6 P.M. to 7:30 P.M., local communication; 7:30 to 11 P.M., standby for broadcast; 11 P.M. and on, long-distance amateur communication.

The article went on to include the following praise: “The average amateur works in a highly technical manner, particularly if he is a member of the American Radio Relay League, an organization of amateurs stretching all over the United States and permitting of constant communication at all times and places.” It concludes by stating that the “amateur promises to be the backbone of our national system of popular radio, now springing into being.”

 



The Flame Audion

One interesting footnote in Radio History can be found in Alfred Powell Morgan’s 1914 book Wireless Telegraph Construction for Amateurs. This is the Flame Audion detector, shown below:

FlameAudion

Morgan describes it thus:

The simple but sensitive form of detector illustrated in Fig. 119 is not of practical value for commercial work, but is very interesting as the progenitor of the audion, and provides a good field for amateur investigation. Its only drawback is that the gas flame is very difficult to keep steady and every flicker registers as a sound in the telephone receivers.

A Bunsen burner using coal gas furnishes the flame, and a salt of an alkaline metal heated in the flame, the ions. The hydroxides of csesium, potassium and sodium give the best results in the order named.

The salt is contained in a piece of trough-shaped platinum foil, about 3/8 inch long and 1/16 inch wide. This trough is made the cathode or negative of the telephone circuit and placed in the outer oxidizing flame just above its juncture with the interior reducing flame and must be kept incandescent. The upper electrode .or anode is a piece of platinum wire about  1/16 inch above the trough.

The arrangement and construction of the detector is clearly indicated by the drawing so that it is unnecessary to go into details. The block, E which fits on the tube of the Bunsen burner, is made of fiber. Two double binding posts, D, are fastened to E to support the rods, R, which are fitted at the tops with binding posts, B, into which the electrodes may be clamped.

Twelve dry cells are connected with a multiple point switch so that an electromotive force of 6-18 volts, varying in steps of one cell at a time, may be secured. The flame is best provided with a mica chimney to protect it from drafts. By keeping plenty of salt in the trough and carefully adjusting the voltage, this detector may be made marvelously sensitive.

This type of detector was the inspiration for the Audion tube. The effect was discovered by the Audion’s inventor, Dr. Lee DeForest, in 1903. DeForest writes in 1947 about this discovery:

I used a Bunsen burner, locating within the flame two platinum electrodes, one of which was connected through the telephone receiver to a dry battery, and thence to the other platinum electode. I enriched the flame with sodium, or common salt.

I then found that when the electrodes were properly located in the gas flame the signals from my spark transmitter were distinctly audible in the telephone receiver. I made countless experiments with this phenomenon; and to prove definitely that the effect was not acoustic but electrical, I connected one of the flame electrodes to my antenna, the other to the ground, and actually obtained wireless signals from ships in New York Harbor.

Radio-Craft, January, 1947

deforestdiagram

DeForest’s Diagram of the Flame Audion Circuit

DeForest applied for a patent in 1905, and was issued U.S. Patent 979275 for the flame detector in 1910.

DeForest wrote about the flame audion himself a number of times. For example, see his articles in Western Electrician, November 3, 1906; the February, 1916, edition of Popular Mechanics; the January, 1947, issue of Radio-Craft.

He wrote a more complete scientific paper which was published in the Transactions of the American Institute of Electrical Engineers in 1906.

DeForest is occasionally criticized for not really understanding what was going on inside the triode. This criticism isn’t really fair. It was later discoverd that the Audion acted as an amplifier. It was quite imperfect as an amplifying tube, because it did not have a complete vacuum. But from reading DeForest’s writings, it is clear that he never intended to invent an amplifying tube. He was working on a detector, and the ionized gas within the tube (which wouldn’t have been there if it had been a true vacuum tube) was responsible for this capability. The amplifying ability was, indeed, a lucky accidental discovery. But particularly looking over the 1906 paper, it’s clear that DeForest was an extremely gifted engineer, and he is worthy of the credit he has received for his advancement of radio in the early years.

It seems to me that students looking for an interesting science fair project might be inspired by DeForest’s work. It combines both fire and electricity. Since it had no reasonable commercial use in the early 1900’s, there was no good reason for scientists to pursue it. But it seems to me that interesting things might be going on inside that flame.

DeForest used platinum wire, which is rather expensive. On the other hand, the cost isn’t entirely out of line. For about $20, you can buy enough Platinum Wire to construct the detector. Platinum foil would be prohibitively expensive, but there doesn’t seem to be any reason why the salt needs to be contained by the platinum. It seems to me that two platinum wire electrodes could be used. And while DeForest used platinum, there doesn’t seem to be any evidence that he experimented with other metals. Would copper perform the same function?

The flame audion was used as a radio detector by DeForest. But earlier scientists had shown that the flame would conduct electricity, a fact that is obvious from the flow of current through the gap. What flames provide better conductivity? Salt is added presumably because it ionizes better than just the fuel and air alone. It would be a relatively simple matter to measure the conductivity of different ionized materials.  Variations in the flame can be heard in the headphones, so for the purpose of making a sensitive radio detector, it’s probably necessary to have a very constant flame.  But for many applications, it seems to me that an ordinary candle would suffice.

(For more science project ideas, see my review of the book Radio Science for the Radio Amateur.)




More Century Old Radio

April1914PMwirelessThe  April 1914 edition of Popular Mechanics includes this Complete Wireless Station for $9.85 from the Nichols Electric Company of 35 Frankfort Street, New York.  That address had housed the “Clean and Ready Company” in 1893.  It now appears to be part of the campus of Pace University, next to the Manhattan entrance to the Brooklyn Bridge.

According to this inflation calculator, the $9.85 cost would be $232.75 in today’s dollars. To look at it another way, that would cost ten silver dollars, or about ten ounces of silver, which would be worth about $200 today. This apparatus seems very similar to one described by Alfred Powell Morgan in his book published in the same year, Wireless Telegraph Construction for Amateurs,  with two exceptions: This set doesn’t appear to have the variable condenser shown in Morgan’s schematic, below.  On the other hand, this set includes a knife switch in order to use the same antenna for both transmitting and receiving.

1914 Morgan Schematic

1914 Morgan Schematic

The receiver is a simple crystal set, billed as being able to receive 1200 miles. I suspect this figure involves a bit of hyperbole, but I suppose with a good antenna and good conditions, it might be possible to occasionally log stations such as NAA, transmitting time and weather from massive towers overlooking Arlington National Cemetery, shown here in 1922.

NAA Towers 1922

NAA Radio Towers, Overlooking Arlington Cemetery. Radio World, November 25, 1922.

 

The transmitter is billed as being capable of transmitting 12-15 miles. The ad doesn’t mention anything about a license. Licenses had been required since 1912, but it’s quite likely that the owner of this set wouldn’t have bothered. In fact, it’s unlikely that he would have been able to receive a license after explaining to the radio inspector what kind of equipment he was using.

The license requirements are explained in Morgan’s book.  Morgan explains:

An amateur may not use transmitting apparatus which is sufficiently powerful to send radio signals across any of the boundaries of the state in which he is located and which can be detected by a sensitive receiving set located just beyond the state boundary, nor can he use apparatus which is powerful enough to interfere with the reception of signals by others from beyond the state boundaries unless he has a license….

In other words if the amateur possesses a receiving outfit only which is in working order or if he has both transmitter and receptor and the.former is not powerful enough to send signals out of the state in which he fives, or to interfere with the reception of messages by another when the messages come from beyond the state boundary a license is unnecessary.
This is of course somewhat unfair for those living near the center of large states for they may operate almost as they please with ordinary instruments with no fear of the signals going beyond the border, while those living within a few miles of another state must secure a license.

Morgan goes on to explain why this set probably wouldn’t qualify for a license:

The law also says that the transmitting wave must be pure, and must be sharply tuned, which means that the wave must be of one length and not, as is very often the case, composed of two or more waves of different lengths.

In order to comply with this restriction, the use of an oscillation helix or loosely coupled helix is necessary. A rotary or quenched gap is also necessary in place of the ordinary spark gap.

The transmitter shown here fails in two regards. First of all, there’s no way of quenching the spark, although I suspect if it was run on batteries, that wouldn’t be much of a problem. The main problem is that the “helix” is basically a tapped autotransformer, and it will probably radiate quite well on at least two wavelengths. In addition, the signal from a transmitter like this is going to have a very wide signal.

I suppose, with a good antenna, this transmitter might be heard 12-15 miles away. But if the owner was more than 15 miles from the state line, it would appear that he could use this without fear of the radio inspector, as long as a licensed station didn’t complain of interference.

By the way, if the name Alfred Powell Morgan rings a bell, you’ll recall why when you visit my Alfred Powell Morgan page.



Minnesota Court of Appeals Throws Out Commercial Vehicle Case

A decision released today by the Minnesota Court of Appeals might put a lot of commercial vehicle equipment tickets in doubt.  The Court held that the commercial vehicle inspector, a civilian employee of the Minnesota State Patrol, had no authority to stop a truck.  Therefore, everything discovered as a result of the stop (namely, that the driver didn’t have a valid license) couldn’t be used in court, and the conviction was reversed.

The case, State of Minnesota v. Kevin Ervin Stall, is discussed in more detail on my website.



Amazon Author Page

This post is a bit of a test.  I did some updates to my author page at Amazon, amazon.com/author/clem.  Among other things, I added a blog feed, and this post is testing whether it shows up there.

Among other things, I’m testing whether this allows me to place live links on the Amazon page, such as links to my other sites:



Radio and Timekeeping a Century Ago

1914PortableRxThe April 1914 issue of Popular Mechanics includes this interesting portable zero-tube radio.  It appears to be a crystal set consisting of a detector mounted directly to the headphone, with two wires for clipping to a convenient antenna and ground connection.

This particular receiver is billed as being for receiving time signals from the Eiffel Tower, which had begun on May 23, 1910.  The station, FL, was operated by the French
Bureau des Longitudes, and transmitted time signals from the Paris Observatory. It operated on 2000 Meters (150 kHz) with a spark transmitter of about 40-50 kW. Service even continued during the war, which began for France about three months after this magazine was published.

Despite the apparent lack of any tuner, a crystal set such as this ought to have been able to receive the signal for quite a distance from Paris. As you can see, the two wires had clips for attaching to any suitable antenna and ground. The signal from the powerful station was so reliable that a guide to receiving the signals, published by the Bureau of Longitude in 1913, was translated and published in English in 1915. The translation is available to read at Google Books.

The original 1913 edition, Réception des signaux radiotélégraphiques transmis par la Tour Eiffel, is also available online.

Any doubts about whether a crystal set would be able to receive the powerful signal should be put to rest by the mere fact that this guide book was published in England. The guide states that the “energy radiated by the Eiffel Tower Station in transmitting signals is great enough to permit the use of receiving aerials of reduced height and dimensions throughout the whole of France and in the French possessions in North Africa.”

Station FL transmitted the exact time nightly at 11:45, 11:47, and 11:49 PM.  And it seems quite likely that the little pocket receiver shown here would have been suitable for receiving it throughout much of France.

The Eiffel Tower time signals had the very practical purpose of an indispensable aid to navigation. There are many ways by which one can determine latitude. But longitude depends on knowing the exact time at a fixed location on Earth, and then comparing that to the local time. One early method of determining the exact time was by observing the moons of Juipter.  Good chronometers largely solved the problem of having to go to these lengths, but there was still the matter of having to periodically set the chronometer. And time signals such as those provided by the Eiffel Tower greatly simplified the process.  A pocket sized receiver such as the one shown here would have been a most useful accessory.