Monthly Archives: April 2017

RCA TP-16A Television Projector, 1947

This RCA ad from the April 1947 issue of Televiser shows how film was broadcast in the early days of postwar televsision. The prewar stations generally had no way to broadcast prerecorded programming. The ability to use film meant that the television production business was a bit less frenzied, without the need to have some live action going on every moment the station was on the air. Film was still a lot more expensive than the later alternative, video tape, but the ability to use film meant that news and entertainment could be shown on a delayed basis. And since there was no live distribution between most cities, the ability to use film also mean that programs could be shipped to other stations, albeit on a delayed basis.

The RCA TP-16A Television Projector, shown at the left, was a self-contained unit which converted film to video. The unit at the right was a two-piece unit, with the film projector at left and video camera at right. The advantage of the dual unit was that it could be used with two film projectors, a mirror being used to switch from one to the other on the fly.

16mm film was already an established format, but there was one problem that had to be overcome. The 16mm format used 24 frames per second, while the video was 60 frames per second. Synchronization was accomplished according to the diagram at the lower right corner of the ad.

The film fed normally at 24 frames per second. During the first frame, the film was illuminated twice, at 1/60 second intervals, and the frame was scanned twice. The net effect was that half of the film frames were scanned three times, and the others scanned two times, for an average of 2-1/2 video frames per film frame. This resulted in the 24 frame per second film being scanned 60 times per second.

The 1000 watt incandescent bulb lit only about 1/1200 second. The video camera had enough inherent memory that it could complete the scan even though it was unlighted.

Battle of Vimy Ridge, 1917

The Battle of Vimy Ridge, painting by Richard Jack. Canadian War Museum via Wikipedia.

Today marks the 100th anniversary, April 9, 1917, of the start of the Battle of Vimy Ridge.

The battle was part of the opening phase of the British-led Battle of Arras in the Nord-Pas-de-Calais region of France, and involved four Canadian divisions against three German divisions.

The Canadians objective was to take control of the high ground, in order to ensure other troops could advance without German fire. The Canadians captured most of the ridge during the first day of the battle.

The battle marked the first occasion when all divisions of the Canadian Expeditionary Force participated in a battle together, and became a symbol of Canadian national achievement and sacrifice.

British and Canadian losses totalled 3598 dead and 7004 wounded.

Bataan Death March, 1942

Wikipedia image.

Today marks the 75th anniversary of the start of the Bataan Death March,
which began on April 9, 1942. After the fall of the Philippines, the Imperial Japanese Army forcibly transferred between 60,000 and 80,000 American and Filipino prisoners of war. The prisoners were marched about 60 miles and then placed on trains.

During the march, between 5000 and 18,000 Filipino solders died, as did between 500 and 650 Americans. The march was later judged to be a Japanese war crime.

Amateur Radio Shut Down, 1917

QST, April 1917.

With the declaration of war, Amateur Radio in the United States was shut down for the duration. Both transmitting and receiving were banned, and amateurs were required to take down their antennas.

The official order was printed in QST, May 1917:

DEPARTMENT OF COMMERCE
NAVIGATION SERVICE
Office of Radio Inspectoor

To all Radio Experimenters,

Sirs:

By virtue of the authority given the President of the United States by an act of Congress, approved August 13, 1912, entitled “An Act to Regulate Radio Communication,” and of all other authority vested in him, and in pursuance of an order issued by the President of the United States, I hereby direct the immediate closing of all stations for radio communications, both transmitting and receiving, owned or operated by you. In order to fully carry this order into effect, I direct that the antennae and all aerial wires be immediately lowered to the ground, and that all radio apparatus both for transmitting and receiving be disconnected from both the antennae and ground circuits and that it otherwise be rendered inoperative both for transmitting and receiving any radio messages or signals, and that it so remain until this order is revoked. Immediate compliance with this order is insisted upon and will be strictly enforced. Please report on the enclosed blank your compliance with this order, a failure to return such blank promptly will lead to a rigid investigation.

Lieutenant, U.S. Navy,
District Communication Superintendent

US At War: April 6, 1917

Chicago Tribune, April 6, 1917.

One hundred years ago today, April 6, 1917, the United States entered the First World War when Congress declared war on Germany. President Wilson, in an address to a joint session of Congress on April 2, had asked for the declaration, citing unrestricted German submarine warfare and the Zimmermann telegram. The Senate passed the resolution on April 4, with the House following on the morning of April 6.

1937 Popular Mechanics One Tube Shortwave Regen

Contrary to your initial impression, this is not an illustration of Junior helping Grandmother with her knitting. Instead, Grandmother is kindly obliging Junior in winding a coil for his new one tube radio. The radio builder is now almost a centenarian, since the illustration comes from the April 1937 issue of Popular Mechanics, which carried the plans for a simple one tube regenerative shortwave receiver.

While the set was designed for the beginner, the circuit used a dual triode 6N7, and the inexpensive set demonstrated a “DX getting” ability equal to many sets with several tubes. It had a tight bandspread which made it an excellent performer in the crowded amateur bands as well as the 19 and 31 meter broadcast bands.

One half of the tube served as regenerative detector, with the other half serving as an audio amplifier to drive he headphones. In addition to the 6 volt filament supply, the set required a B+ of between 45 and 135 volts. While a battery eliminator could be used to run the set off household power, the article recommended use of batteries for best performance.

The chasis consisted of a wooden base, with an aluminum front panel. For tuning, one of the variable capacitors was set to the approximate frequency, with the smaller variable used to tune in the station’s exact frequency.

Coil winding instructions were included for four coils, covering the 160, 80, 40, and 20 meter bands. With all of those coils to wind, Grandmother’s help was almost certainly appreciated.

An antenna of 40 to 50 feet was recommended, and the illustration here shows Father helping to install it. So that he can grow to become a centenarian, Junior is safely on terra firma while dad takes care of the climbing.

Clandestine English Receiver in Norway

The 1945 issue of Radio Missionary Log, the program guide for HCJB, Quito, Ecuador, carried this letter and photo which the station had received after the war. The writer, Kjell Gaarder of Norway, wrote that he had received HCJB on the receiver shown.

HCJB did not carry a Norwegian broadcast, but Mr. Gaarder listened to the station’s Swedish broadcast. He noted that there probably hadn’t been many reports from Norwegian listeners during the war, since the Nazis had seized all radio receivers in 1941, and prohibited listening on pain of death. But Mr. Gaarder reported that he “received, however, a small three-valve receiving set from England by parachute,” and had listened to HCJB with it.

According to the program guide, HCJB was broadcasting in Swedish ninety minutes per week, from 4:30-5:00 PM U.S. Eastern Standard Time (the same as local time in Quito) on Sunday, Tuesday, and Thursday. The broadcasts were on 12.5 MHz, the station’s main frequency, with 10,000 Watts. The Swedish broadcast would have also gone out with 1000 watts on 9.9 and 6.2 MHz.

Curiously, the book The Portable Radio in American Life mentions an RCA engineer named Kjell Gaarder, who made some adjustments to a small radio in 1940 to make it smaller. It seems inconceivable that two small radios in different parts of the world just happened to have a connection to someone with the same unusual name. It seems almost certain that the RCA engineer in America in 1940 was one and the same as the person who just happened to receive a radio delivered by parachute a few years later.

I suspect that Mr. Gaarder returned to Norway during the Nazi occupation, and probably participated in the resistance, as evidenced by his British radio. There must be an interesting story here, and I hope some reader can give me some clues as to that story.

Wilson Asks for War: 1917

Wikipedia image.

On hundred years ago today, April 2, 1917, President Wilson addressed a joint session of Congress and asked for a declaration of war against Germany.

In his address, Wilson first told the assembled Congress that there were “serious, very serious, choices of policy to be made, and made immediately.” He first cited the German government’s declaration on February 3 or unrestricted submarine warfare in the Atlantic and Mediterranean, which he called “a warfare against mankind.”

It was clear that Wilson saw the role of the United States as a superpower who would win the war through overwhelming national power:

What this will involve is clear. It will involve the utmost practicable cooperation in counsel and action with the governments now at war with Germany, and, as incident to that, the extension to those governments of the most liberal financial credits, in order that our resources may so far as possible be added to theirs. It will involve the organization and mobilization of all the material resources of the country to supply the materials of war and serve the incidental needs of the nation in the most abundant and yet the most economical and efficient way possible. It will involve the immediate full equipment of the Navy in all respects but particularly in supplying it with the best means of dealing with the enemy’s submarines. It will involve the immediate addition to the armed forces of the United States already provided for by law in case of war at least 500,000 men, who should, in my opinion, be chosen upon the principle of universal liability to service, and also the authorization of subsequent additional increments of equal force so soon as they may be needed and can be handled in training. It will involve also, of course, the granting of adequate credits to the Government, sustained, I hope, so far as they can equitably be sustained by the present generation, by well conceived taxation.

And while Wilson stated that the United States had no quarrel with the German people, it’s government, as evidenced by the Zimmermann telegram, was evidence of “criminal intrigues everywhere affot against our national unity: ” That it means to stir up enemies against us at our very doors the intercepted note to the German Minister at Mexico City is eloquent evidence.”

The country would be at war within four days. The Senate approved the declaration of war on April 4, with the House approving it on April 6.

1957 Swiss Spaghetti Harvest

Sixty years ago, spring had come to Switzerland. The last two weeks of March are traditionally the spaghetti harvest. The 1957 harvest was notable due to the eradication of the dreaded spaghetti weevil, which had devastating effects on prior crops.

Switzerland’s spaghetti production is, of course, on a much smaller scale than the large Italian plantations. The harvest of the uniformly sized spaghetti is more of a family affair in Switzerland.

You can see more in this video, which aired sixty years ago today on the BBC on April 1, 1957.

OneTubeRadio.com

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