"Wavescan" is a weekly program for long distance radio hobbyists produced by Dr. Adrian M. Peterson, Coordinator of International Relations for Adventist World Radio. AWR carries the program over many of its stations (including shortwave). Adrian Peterson is a highly regarded DXer and radio historian, and often includes features on radio history in his program. We are reproducing those features below, with Dr. Peterson's permission and assistance.
Wavescan, July 17, 2011
Jungle Radio in South America: The Terry-Holden Expedition VP3THE
The South American country of Guyana is located at the top of the continent. It is just a small tropical country, 400 miles long and 300 miles wide, with a total population of less than one million, half of whom trace their origins back to India, over there in Asia. The capital city is Georgetown, with its unique floating bridge more than one mile long.
If only the noted Charles Darwin had visited this country now called Guyana in South America, he would have discovered a multitude of unique varieties there, more than he did in his famous expedition to the Galapagos Islands during the 1830s. It is stated that Guyana has 4,000 plants that are not found anywhere else in the world, as well as many unique animal species, including the Golden Frog.
In ancient times, Guyana was inhabited by Indians of three different tribes; the Arawak, Carib and Warrau. It was Christopher Columbus who sailed along the coast line of Guyana as the first European visitor to the area in 1498. Almost a century later, the Dutch established the first European settlement, but they ceded the area to England in 1814. The British colony of British Guiana was formally established in 1831.
In 1966 British Guiana gained its independence as Guyana; and four years later, this new country became a republic. Guyana became a center of international interest in the terrible events associated with what is known as the Jonestown Massacre when nearly 1,000 people committed suicide.
Back in the year 1937, a group of six American explorers left the United States for a season of exploration in the northern jungle areas of South America on behalf of the American Museum of Natural History in New York. This expedition, known as the Terry-Holden Expedition, arrived at Georgetown; and they then departed from Bartica, at the mouth of a confluence of local river systems on September 29, 1937 in flat bottom boats for a 500 mile journey inland.
Three weeks later, the expedition established a base camp in the foothills of the Sierra Akarai Mountains near the border with Brazil. Here, they installed a 200 watt RCA shortwave transmitter in a grass hut; this unit was allotted the callsign VP3THE, with the letters THE in the callsign identifying the Terry-Holden Expedition.
An advance party travelled a further 200 miles on horse back, and they took a small 50 watt Collins mobile transmitter with them for regular contact with the base camp.
It was on October 13, 1937, that the expedition station VP3THE was first heard in the United States, on 13900 kHz. On this occasion, VP3THE was in contact with amateur station VP3BG in Georgetown; and interestingly, as the years went by, VP3BG and neighboring VP3MR grew into a commercial broadcasting station with a regularized callsign.
One month after the first test transmission, the expedition station VP3THE was officially inaugurated with the broadcast of a weekly radio report back to the United States for nationwide coverage in the NBC Red and Blue networks. Sometimes the program relay was made via VP3BG and VP3MR in Georgetown, Guyana, and sometimes the relay was carried out direct with the RCA station at Rocky Point on Long Island.
Three months after the initial test broadcast, the expedition station VP3THE left the air, never to return again. The final broadcast was made early in the new year, on January 15, 1938. The operator, Orison Hungerford, arrived back in New York three months later, during the month of April.
Two very different QSL cards were issued to verify reception reports of the Terry-Holden Expedition. One was the familiar duplicated plain text card with a hand drawn microphone issued by NBC in New York. These cards were non-specific regarding the information in the QSL text. The other card was a large folder card, containing three photos of the station out in the jungle, and brief details of the expedition, as well as full QSL details.
Radio Panorama RP11: Spark Flashes Through the Air, Pt. 2
In our continuing series of topics under the title Radio Panorama, we are looking at early electrical spark flashes through the air, and we begin with Germany.
In the meantime, Heinrich Hertz was also actively engaged in wireless research. In 1886, while employed as a professor at the Karlsruhe University in Germany, he began his experiments using a simple transmitter and a simple receiver.
As the transmitter, Hertz used a high voltage induction coil coupled to a spark gap, and powered with electricity from a Leyden Jar. Two brass spheres 1-1/2 inches in diameter at each end of the wire coil formed the spark gap.
The receiver consisted of a thin brass wire bent into a circle with a diameter of 3 inches. A small brass sphere was attached to one end of the receiving circle, and the other end was sharpened to a point, close to the small sphere. When electricity was applied to the transmitter, a tiny spark was seen across the small spark gap in the nearby receiving apparatus.
It was in the year 1888, that Professor Richard Threlfall successfully repeated the Hertz experiments at the Sydney University in Australia. This was in the same year, 1888, that Heinrich Hertz in Germany published the results of his extensive experiments. Two years later, Threlfall himself published his own findings in an Australian scientific journal.
Another early experimenter in Australia was Mr. C. W. Selby of Melbourne, and he built his own similar equipment based upon an article in a scientific journal that was published in England in 1892.
Five years later, at the conclusion of a lecture presented by Professor William Bragg at the Adelaide University, a co-worker, Mr. A. Paton, successfully demonstrated similar wireless equipment on September 21, 1897. Two years later, communication was extended to one mile, with the transmitter at the Adelaide Observatory and the receiver in a nearby suburban area.
The longest test transmission in Adelaide during these experiments took place on June 23, 1899, with a one way transmission from the Observatory to a receiver at a coastal location at Henley Beach, a distance of five miles. Three weeks later, two way communication was achieved at the same two locations.
Meanwhile over in New South Wales, the Engineer in Chief for the PMG telegraph system, Mr. P. E. Walker, gave a public demonstration in the Long Room at the General Post Office in Sydney. The press was invited to the event, which took place on August 10, 1899.
Then again, just two months later, another similar wireless experiment was conducted on the other edge of the continent, in Perth, Western Australia. The transmitting equipment was loaded into a police launch and a receiver was installed on shore in the Royal Yacht Club building.
A few weeks later again, an additional similar experiment was carried out, this time with the transmitter ashore and the receiver in the launch as it made its way out to nearby Rottnest Island. Reception was heard to about one mile off shore.
Over in Hobart, Tasmania, a man by the name of T. E. Self constructed his own wireless equipment and he advertised in the newspaper that he would make a demonstration of this equipment during a public lecture.
The Australian navy began wireless experiments in Queensland in 1900, with successful tests between the Canadian navy ship Gayundah and the shore at the navy depot in suburban Brisbane.
New Zealand featured early in wireless experimentation, and in 1888 New Zealander George Kemp began experimental transmissions at Gisborne; and eleven years later, he gave an open demonstration at the Canterbury University in Christchurch. Another early experimenter in New Zealand was Sir Ernest Rutherford, who transmitted an electrical signal wirelessly for a distance of 50 feet at the Canterbury Campus of the University of New Zealand in 1894.
During the year 1889, Hantaro Nagaoka gave a public demonstration of his wireless equipment at the University of Tokyo.
France also featured early in wireless history and it was Edouard Branly who improved the coherer from its original form as developed by Temistocle Calzecchi-Onesti in Italy four years earlier. The Italian experimenter placed copper filings in a glass tube, but Branly experimented with several different forms of filings, including iron.
In Brazil, during the year 1892, de Moura made several wireless experiments at Sao Paulo and Campinas.
Postage stamps printed in Russia proclaim that Alexander Popov was the inventor of radio. In 1894, Popov constructed his own wireless receiver independently, and he did so for the specific purpose of listening to the electrical strikes of distant lightning storms. However, the equipment was in reality a standard wireless receiver at that era.
One year later, he gave a demonstration of his equipment to a Russian scientific society, and that was on May 7, 1895. It is claimed on his behalf that he was slightly ahead of the Marconi experiments in Italy.
Parallel with the wireless developments in continental and islandic Europe was similar research and experimentation in India. The noted work in the Indian sub-continent in the days of the British Raj was conducted by Jagadish Chandra Bose who was born in Munshiganj in 1858. At the time, Munshiganj was considered to be a part of India though these days it is located in Bangladesh.
In June 1894, the Englishman Sir Oliver Lodge published a book regarding his own wireless experiments based on the earlier experiments conducted by Heinrich Hertz in Germany. Bose read this documentation on wireless experimentation and he performed similar experiments in India.
In November 1895, Bose gave a pubic demonstration in the Calcutta Town Hall, using equipment that produced transmission at a very short wavelength, in the range of just a few millimetres. The transmitted signal in the Calcutta demonstration rang a bell at a distance, and also ignited nearby gun powder.
During the following year, Bose traveled to London for the second occasion, where he met Marconi who was conducting wireless experiments for the British Post Office at the time.
In May and June 1899, the Spanish military officer, Julio Cervera Baviera, spent time with Marconi in England, where he also studied the Marconi wireless installations on the edge of the English Channel. Cervera returned home to Spain where two years later he established the first wireless service in his country, between Tarif on the southernmost coast of the Iberian peninsula and Ceuta, 20 miles away in Spanish North Africa.
Cervera then went on to found the Spanish Wireless & Telephone Corporation which established additional wireless networks throughout Iberia. He is credited with several wireless patents ahead of Marconi and he is honored in Spain as the ultimate founder of radio.