Category Archives: Radio history

Measuring Longitude Between Washington and Paris, 1914

LongitudeRadioIn an earlier post,
we showed how radio was being used in 1924 for accurate measurements of longitude. And the newspaper a hundred years ago today, November 21, 1914, shows the work that was taking place then. This clipping from the New York Sun shows measurements of longitude being made between Paris and Washington.

The Eiffel Tower radio station continued in service throughout the war, and a hundred years ago, it was busy comparing time signals with its counterpart in Arlington, Virginia, station NAA. By comparing the instant of local noon at both locations, the tests were able to very accurately measure the difference in longitude. The time difference between the two observatories was found to be 5 hours, 17 minutes, and 36.658 seconds. This corresponds to a difference in longitude of 79.40274 degrees.


Today’s Ripley’s Believe It Or Not Cartoon



Knight-Kit Star Roamer Receiver, 1964

KnightStarRoamer

Fifty years ago this month, November 1964, Electronics Illustrated reviewed Allied Radio’s Knight-Kit Star Roamer Receiver.  I never had one, but this basic receiver was ubiquitous in the 1960’s and 1970’s, and many SWL’s got their start with the four-tube receiver.

According to the magazine, the kit sold for $39.95 and took about 20 hours to build.  The receiver’s low tube count was courtesy of a selenium rectifier and solid-state diode detector.  The radio did receive CW, but without a BFO.  The final IF stage was designed so that it could break into oscillation, making the receiver quasi-regenerative.  Interestingly, the radio included a key jack, since the oscillating stage could be used as a code practice oscillator for an aspiring novice to work on learning the code.


The receiver tuned 200 kHz to 30 MHz, but as the review points out, the longwave band was almost useless, and the overall performance left a lot to be desired.  But in an environment filled with strong shortwave signals, even a simple receiver like this one would give hours of interesting listening to the new SWL.

Good specimens seem to go for about $50 on eBay.  But if you’re in the market, there’s really no sense in getting a working one.  The simple receiver is easy to work on, and the full assembly manual is readily available.  This receiver would be a good candidate to “re-kit”: Take it apart, and keep the mechanical parts, IF transformers, and variable capacitors.  Then,  replace the resistors and capacitors with modern replacements.  The selenium rectifier is probably best replaced with a more modern silicon rectifier.  The old tubes are almost certainly good, and even if they are not, they are all easily obtainable as “new old stock.”  Finally, put it back together according to the manual (and the cautions contained in the EI review).



Houdini’s Ice Escape Explained…Except for One Small Detail

HoudiniRiver

Houdini going in to the Detroit River (from the 1953 Paramount movie)

Seventy years ago today, November 17, 1944, the Milwaukee Journal carried an interesting item about the escape artist Harry Houdini.  The previous Sunday, November 12, the radio program John Nesbitt’s The Passing Parade had carried a description of Houdini’s famous escape from under the ice covered waters of the Detroit River.  This stunt was immortalized in the  1953 Paramount Movie Houdini starring Tony Curtis as Houdini.  A still from the movie of the great escape artist’s crate being dropped into the icy water is shown here.

The Journal’s radio editor recounts the broadcast describing the “famous occasion 35 or more years ago when Houdini jumped into the Detroit river through a hole cut in otherwise solid ice that covered the river.” According to the paper, Houdini “stayed under water for six–or was it eight?–minutes, well beyond the time limit of known human endurance.” According to the paper, the mayor of Detroit and a “good crowd of sober citizens” witnessed the stunt and had the scare of their lives.

According to Nesbitt, Houdini “knew something.” He knew that the river had fallen an inch or so, and that there was an air-filled void between the surface of the water and the ice. As famously depicted in the movie, Houdini merely went to the surface, breathing the air until he located the hole.

But the mystery was apparently solved by a mysterious letter that showed up at Milwaukee station WTMJ after the broadcast.  The anonymous author of the letter was from Grand Rapids, Michigan,  (It’s quite plausible that the Milwaukee station had listeners in Grand Rapids, since the two locations are separated mostly by the waters of Lake Michigan, over which the groundwave signal of the 620 kilocycle station would easily pass.)  The mysterious author of the letter offered up what seemed to be a very plausible explanation for the stunt.

The radio editor Richard K. Bellamy, opines that “to us it sounds as though the writer of the letter knew what he was talking about.” It also sounded to me like the writer knew what he was talking about, since he included a number of corroborating details.

The anonymous letter writer stated that he was an “expert diver” and “one of Harry’s accomplices on that day” and that he was paid $350 for his part. According to the writer, a sheet metal worker in Brooklyn fabricated a can which was filled with compressed air. The letter writer’s job was to place that can in the river, which he says he did the Sunday prior to the stunt. “Harry and I carefully measured the distance” from the hole in the river to the can, says the writer. The can was attached to “a sort of head mask and some rubber hose.” “He could have stayed under 30 minutes,” opined the writer.

The mysterious letter writer does offer some corroborating details. He notes that there “probably is, or was, a tinsmith in Brooklyn who could corroborate part of my story.” He noted the exact location, noting that “if you will check today, you will find a quantity of concrete piling along the banks of the river,” and that the can and its anchor “is probably still at the spot” under the water. He concludes by noting that “a little research will probably bear me out.”

The letter writer says that he can’t divulge his identity “for ethical reasons.” But he believed that it “is hardly fair to the radio public to let the hoax explanation be unchallenged.”

That certainly seems like a plausible explanation.  After all, anyone could have gone to take a look at those concrete pilings.  And retrieving, or at least locating, a large cylinder and concrete anchor down at the bottom of the river doesn’t seem like a major undertaking.  And the anonymous explanation certainly seems more plausible than breathing, for an extended period of time, the tiny bit of air trapped under the ice.  So the radio columnist was apparently convinced.  And I was almost convinced, but for one small discrepancy.

That discrepancy was that the supposed ice escape, with or without assistance, never took place.  The mayor of Detroit didn’t witness it, the sober citizens of Detroit never witnessed it, and Houdini never did it.  It simply never happened, as shown at some of the links below.

Fact checking was harder before the Internet.  For a news story, a reporter might be expected to go down to the vault and find clippings about an event “35 or more years ago.” But this wasn’t a news article, and they didn’t have that Google thingie to help with the fact checking.  It was just an account of an interesting letter sent anonymously to a radio station. And it was a good story, good for a few column inches.  If I were the editor, I would print it, too.

Who sent it?  It could just be some guy playing a practical joke.  Or perhaps it was a publicist hyping a movie that wouldn’t come out for another nine years.  It seems like a good way to reinforce the “ice escape” story:  Plausibly explain how it was “really” done, without quite enough details to disprove the official version of the story.  It seems to me that adds a little bit of credibility to an official story that never happened.

 References

Read More at Amazon

 


1934 Philco Ad

1934Philco

Eighty years ago today, November 16, 1934, the Milwaukee Journal carried this ad for this Philco “lowboy” console radio for $59.95. You could have the radio installed in your home for ten percent down.

The radio is Philco model 45L, and covered both standard broadcast and short wave. In fact, this package included a short wave antenna kit, a Radio Atlas of the World, and an “Admiral Byrd Revolving Globe.”

The receiver was probably a pretty good performer. It had six tubes, and two IF stages. You can find a schematic and more information at RadioMuseum.org.



Emergency 1943 Radio Receivers, Including Converting Lightbulb to Diode Tube

Converting dual-filament lamp to diode tube

A homemade diode vacuum tube.

A wartime issue of Radio News, January 1943, includes an interesting article entitled “Emergency Radio Receivers.” The article notes that “‘horse and buggy’ receivers employing the simple detectors are just as workable today as they ever were.” With wartime tube and battery shortages, and the possibility of power line disruptions, “the present war emergency may yet recall these simple sets from their resting places on museum shelves.” Their greatest value in time of war was as emergency receivers. “Such sets may be placed into immediate service when power lines have snapped out and “B” batteries are not available for the family portable. They may be carried into bomb shelters where electric power is not available. Particularly unique is the fact that they may be made so small in size as to be carried easily in a pocket or handbag.”

This was not the last time that the usefulness of crystal sets was considered for emergency preparedness. A 1963 Office of Civil Defense report noted that for the “economy minded,” even a crystal set would be adequate for receiving local broadcasts after a nuclear war.

The article then describes a number of possible crystal detectors that could be used in an emergency receiver. (One not mentioned was the razor blade of the foxhole radio, which made its debut the following year, in 1944.)

VHF Crystal Set

VHF Crystal Set

For those interested in experimenting with crystal sets, the article provides a good introduction to the subject. Three of the ideas shown are rather novel. The first is an “effective crystal circuit for fixed-frequency ultra-high-frequency reception,” shown here. The terminology has changed, and we would today call these VHF frequencies. It notes that this circuit provides “interesting possibilities for portable (personal) use in short-range civilian defense communications employing the ultra-high WERS (War Emergency Radio Service) frequencies” of 112-116 and 219-225 MHz. Contrary to popular perception, there’s no reason why a crystal set can’t be used on VHF. In fact, here’s one interesting example of a crystal set for the FM broadcast band.

CW Crystal Set

CW Crystal Set

The article also shows a method for receiving CW signals on a crystal set, a task I would have thought to be impossible without some active component such as a tube or transistor. The article explains that to receive CW, it is only necessary “to include in the circuit some form of continuously-running, high speed interrupter.” It shows how to do this with a motor-driven commutator which interrupts the RF circuit. This makes the CW signal audible, with a pitch proportional to the speed of the interrupter. A rheostat controlling the speed of the motor thus adjusts the CW pitch.

Converting dual-filament lamp to diode tube

Converting dual-filament lamp to diode tube

But the most remarkable idea in this article is making a homemade vacuum tube diode using a double-filament lamp. The article explains how a diode tube can be made from a type 1158 lamp. This lamp, which is still readily available, has two filaments, one brighter than the other. The brighter filament is intentionally burnt out by applying a high voltage. This leaves the other filament intact. The good filament is then used as a directly heated cathode. And the support rod for the burnt out filament acts as the plate of the tube. The result is that the automotive light bulb is converted into a diode vacuum tube. It is used in the circuit shown here as a radio receiver:

Radio circuit using light bulb detector

Radio circuit using light bulb detector

The article notes that the filament has a rather high current (about 750 mA for a modern example), but “this drawback should not be of monumental concern if the diode receiver is to be operated during rather short, emergency periods.”

Any dual-filament DC bulb should serve the same purpose, but the 1158 bulb specified in the article is still readily available. It’s probably available at a local hardware store, and it’s also available at a reasonable price from Amazon. Since six-volt automotive bulbs aren’t very common these days, it would probably be better to substitute the 12-volt version, the 1157, which should be available at a local auto parts store, or online at Amazon or WalMart
icon. Another possible option would be to use a 120 volt 3-way light bulb. In that case, of course, you should take care to keep the headphones isolated from the AC line.

For ideas on where to get other needed parts, you can check my crystal set parts page.


1940 Armistice Day Blizzard

Armistice Day Blizzard, Excelsior Blvd., West of Minneapolis.  Minn. Historical Society photo, NOAA.

Armistice Day Blizzard, Excelsior Blvd., West of Minneapolis. Minn. Historical Society photo, NOAA.

For many, the eleventh day of November is remembered as Armistice Day or Veterans’ Day. In Minnesota and much of the Midwest, it’s also remembered as the date of the Armistice Day Blizzard of November 11-12, 1940.

The storm came up quickly and was responsible for 145 deaths, including 49 in Minnesota. About half of those 49 were duck hunters who froze to death, unable to escape the sudden storm.

MilwAdThe severity of the storm was largely unpredicted. The newspaper forecast in the Milwaukee Sentinel was typical of that appearing in Midwestern papers. It called for “cloudy with occasional rain in south and rain or snow north; colder Monday (the 11th); Tuesday (the 12th) cloudy, possibly snow flurries and colder.” Ironically, that paper included the  advertisement shown here for overcoats, warning, “you can never depend on Milwaukee weather,” and “there’ll come a day, not so very far away, when scenes like this will be commonplace all around town.”

Those scenes came to the Midwest much faster than anyone expected.  Within hours, temperatures were dropping, massive amounts of snow fell, and winds caused peril to those on both land and water.

The storm disrupted communications through much of the region, as telephone and telegraph lines were taken down by the fierce winds.  As might be expected, Amateur Radio operators stepped in to fill the need, as reported in QST for January, 1941.  Hams provided communication to the railroads, the Red Cross, and especially for private citizens, since broadcast stations broadcast the telephone numbers of local hams who could relay messages to towns cut off by the storm.  Minneapolis Ham George H. King, W9OTE, reported that his phone rang constantly with requests from worried families, with his wife unable to prepare dinner because of the constant calls.

A couple of familiar names appear in the QST article.  The first was Stanley L. Burghardt, W9BJV, of Watertown, S.D., who contacted the families of dozens of Watertown residents who were stranded in Minneapolis.  Burghardt’s call later became W0IT, and is famous among Hams as the owner of Burghardt’s Amateur Center in Watertown.  Burghardt’s antenna collapsed in the blinding gale, forcing him to go outside to effect a repair that held until the storm ended.

Another familiar name in this story was that of Sherman Booen, then of Albert Lea, MN, W9HRT. He reported that most of the wire facilities in Albert Lea had been wiped out, and he reported that 75 meters was a beehive of activity. He reported that he went to bed, but at 10:30 PM, a railroad dispatcher in Albert Lea called him. The dispatcher had been unable to contact his chief in Minneapolis, and needed to get through for permission to start a snowplow north. Booen was able to get that message through in ten minutes. A total of 15 railroad messages were relayed by Booen.

The name Sherman Booen is familiar to many Minnesotans. After the war, his call sign became W0RHT, and he was a well-known Ham. He was also an aviator and broadcaster, and best known as the host for 28 years of “World of Aviation” on WCCO-TV in Minneapolis. He passed away in 2011 at the age of 97, having been licensed as a Ham since 1934.

Read More at Amazon



 

 

Destruction of the Emden, 1914

Emden

A hundred years ago today, November 10, 1914, the American papers were all reporting the sinking of the SMS Emden in the Cocos Islands. The headline shown here is from the New York Evening World.

Upon learning of the assassination of Archduke Franz Ferdinand, her captain, Karl von Müller, anticipated war and prepared for commerce raiding in the Indian Ocean. He captured a Russian freighter soon after the outbreak of hostilities, and continued to operate in the region, terrorizing allied commerce, capturing almost two dozen ships. In October, Müller decided to attack the British coaling station in the Cocos Islands, which was equipped with a wireless station. Müller’s intention was to destroy the wireless station, and also attempted to jam the signal. But the station was able to get out a message that an unidentified ship was off the entrance of the harbor. The Australian cruiser HMAS Sydney was only 60 miles away. The Emden picked up the Sydney’s wireless signals, but believed that the Australian ship was much further away.

The Sydney’s six inch guns were able to inflict serious damage to the Emden. The Emden was ultimately beached, and scrapped in the 1950’s. A raiding party had already landed on the island, and was left to its own devices. The landing party seized another ship and sailed to Yemen, which was then part of the Ottoman Empire, an ally of Germany.

Read More at Amazon


A Toy TV for Half the Price of a Real One

PhonoViewer

Fifty years ago this month, the November, 1964, issue of Radio-Electronics magazine
announced the debut of a “new educational toy in the spirit of TV,” the General Electric Show ‘n Tell Phono Viewer. It consisted of a phonograph, capable of playing all speeds of records (16, 33, 45, and 78). It also conntained of a slide viewer which displayed special film strips that were available synchronized with the accompanying record. The slides advanced mechanically, timed by the rotation of the turntable. According to the article, a 3-year-old child would be able to load both the record and slide. (This was back in the day when parents weren’t overly paranoid when it came to entrusting 120 volt devices to their three year olds.)

The original selling price was $29.95. I vaguely recall seeing these, but they didn’t offer much fascination. This is probably because real TV’s started at $59.95. No matter the retailer, the least expensive television was invariably $59.95. This amount was never attainable, but it always seemed to be within reach. If I had ever come into possession of $29.95, I doubt if I would have considered squandering it on a toy TV, no matter how ingenious, knowing that I was halfway to being able to purchase a real one.

The device can be seen in action at this YouTube video.


World’s Largest Radio Tower, Tuckerton, NJ

TuckertonTower

This photo from the November, 1914, issue of Popular Mechanics shows the world’s largest radio tower at Tuckerton, New Jersey.

The caption notes that the station was now under the control of the U.S. Navy Department. As mentioned in an earlier post, this station was originally German and part of the Goldschmidt System, and communicated with the German station near Hanover. Even though under Navy control, German nationals continued to operate the station until the U.S. entered the war, at which time the staff became prisoners of war.

The tower itself stood 680 feet tall. At the time, it operated with the call signs WCI and WGG. After the war, the station was seized by the U.S. Government as part of Germany’s war reparations, and was sold to RCA, which operated it under the call sign WSC. The tower was taken down in 1955, but its three massive anchor blocks still exist. A good set of photos of these massive monolith cubes can be viewed at this site.


Radio and the Longitude Problem

RadioLongitude

The wireless telegraph  solved the Longitude Problem once and for all.    Many maritime disasters over the centuries were the result of sailors not knowing their longitude. Determining latitude is relatively simple. From any position on earth, it is easy to determine the local time by observing the sun or stars. When the sun is at its highest point for the day, this is, by definition, noon local time. The sun’s altiude at that time can be used to quickly determine the observer’s latitude.

Longitude, however, was a much more difficult problem. With instantaneous communication, it’s trivially simple to determine longitude. The observer merely determines local noon, and then compares that with the local time at a known longitude. The difference in time can quickly be converted to difference in longitude. If it is noon at my location, and I know that it is 6:00 PM at Greenwich, then I instantly know that I am 90 degrees west of Greenwich. The time diference is 6/24 of one day, which is 1/4. Therefore, the difference in longitude is 1/4 of 360 degrees, or 90 degrees.

Of course, instantaneous communication was not availalbe for most of the history of navigation. Therefore, the problem remained formidable. It wasn’t until the late 1700’s that sufficiently accurate chronomoters became available. And even then, a backup method (careful observation of the eclipses of known stars by the moon) involving laborious calculations was required.

These problems were  solved by the use of wireless time signals. A mariner could set his chronometer accurately (generally, to about a tenth of a second) by use of time signals broadcast by stations such as NAA in the United States or the Eiffel Tower in France.

But even as recently as 90 years ago, this problem was still receiving attention, as shown by the article in the November, 1924, issue of Radio News. Listening to the time signal by ear and noting the time on the chronometer was accurate enough for maritime navigation. But for land surveying, a more precise automated method was necessary. Telegraph lines could be used, but the relays used in long lines introduced a delay. Radio was ideal, since the only delay was the speed of light, and even that could be accounted for. The article explains how the time radio time signal from the naval observatory was graphed along with the time from a locally calibrated chronometer. The result was a very accurate indication of the time difference, and thus the longitude difference, between the two locations.

The article shows how the time signal from Annapolis, Maryland, was used to determine exact longitude in Skagway, Alaska, 3000 miles away.

Read More at Amazon