DELARANEWS

Joe … the Other Joe

Joe Fischer, AA8TA

It’s not easy crossing “The Pond”

After we have experienced things for many years, or generations, we do not ever think that there is any other way for whatever it is to be. Thankfully, a lot of medicine is that way and, hopefully, more will become common later on. So it was when I was researching something or other and came across an article in the IEEE Antennas and Propagation Society Newsletter from December, 1982. This was a review of the 80th anniversary of Guglielmo Marconi’s successful experiment of transmitting a radio signal across the Atlantic Ocean. In the late 1800’s it was accepted that electromagnetic radiation could be produced and picked up over short distances. James Clerk Maxwell established that light was also a form of electromagnetic radiation. We understand that light, microwave radio signals and (most of the time) UHF and VHF radio waves use straight-line communication channels. Marconi had the resources and some connections that he was able to conduct ever more sophisticated experiments and found that radio waves could travel over hills and other obstacles and, amazingly, seemed to show an ability to follow the curve of the Earth. This was not what people expected and contradicted conventional wisdom of the time. This was a surprise. Marconi’s experiments involved an antenna that had part of it buried in the ground. It was thought that this was significant and had something to do with creating a ground wave or a radio wave that was somehow connected to the surface of the Earth. Marconi then began thinking that it might be possible to transmit a radio signal across the Atlantic Ocean. A little amusing, to me, divergence here. After setting up a station in Poldhu, England, he went to St. John’s Newfoundland and the next day met the governor, prime minister and other government officials and was promised full cooperation from them. Imagine that, some dude from Italy showing up and getting the red carpet treatment from government Poo-Bahs. In this day and age, one would be lucky to get within 10 miles of some government hot-shot and talking to him would not be possible without a big campaign donation check. Anyway, Marconi succeeded and proved that radio waves could be made to follow a substantial curvature of the Earth. It did seem highly unlikely that a ground wave could possibly cover that distance and further investigations (not by Marconi) led to the discovery of the ionosphere. At the time, it was thought that covering long distances meant lowering the transmit frequency. Marconi was using a 25 kW AC generator operating at about 16 kHz. Such operations were very expensive, not just in the electrical power needed but the substantial antenna system required. It was a surprise to Marconi that raising the frequency was the key to success. For example, he found that a transmitter operating at 3.25 MHz with 12 kW could cover thousands of kilometers of the Earth at night. Further experiments showed that at 20 meters (wavelength), considerably less power could send a radio wave around the world during daylight conditions. Must have been some good sunspots back then. From there, things took off. Marconi was lucky that he seemed to have almost unlimited resources to conduct a variety of experiments. He was persistent at trying different things and adapting when things did not work out. For example, when high winds toppled his original circular array of antenna supports in Poldhu, he came up with something else. He was meticulous at recording his results and devising the next experiment after that. And, when long-distance communication became a commodity, he got rich. Some lessons there.
DELARANews

Joe … the Other

Joe

Joe Fischer, AA8TA

It’s not easy crossing “The Pond”

After we have experienced things for many years, or generations, we do not ever think that there is any other way for whatever it is to be. Thankfully, a lot of medicine is that way and, hopefully, more will become common later on. So it was when I was researching something or other and came across an article in the IEEE Antennas and Propagation Society Newsletter from December, 1982. This was a review of the 80th anniversary of Guglielmo Marconi’s successful experiment of transmitting a radio signal across the Atlantic Ocean. In the late 1800’s it was accepted that electromagnetic radiation could be produced and picked up over short distances. James Clerk Maxwell established that light was also a form of electromagnetic radiation. We understand that light, microwave radio signals and (most of the time) UHF and VHF radio waves use straight-line communication channels. Marconi had the resources and some connections that he was able to conduct ever more sophisticated experiments and found that radio waves could travel over hills and other obstacles and, amazingly, seemed to show an ability to follow the curve of the Earth. This was not what people expected and contradicted conventional wisdom of the time. This was a surprise. Marconi’s experiments involved an antenna that had part of it buried in the ground. It was thought that this was significant and had something to do with creating a ground wave or a radio wave that was somehow connected to the surface of the Earth. Marconi then began thinking that it might be possible to transmit a radio signal across the Atlantic Ocean. A little amusing, to me, divergence here. After setting up a station in Poldhu, England, he went to St. John’s Newfoundland and the next day met the governor, prime minister and other government officials and was promised full cooperation from them. Imagine that, some dude from Italy showing up and getting the red carpet treatment from government Poo-Bahs. In this day and age, one would be lucky to get within 10 miles of some government hot-shot and talking to him would not be possible without a big campaign donation check. Anyway, Marconi succeeded and proved that radio waves could be made to follow a substantial curvature of the Earth. It did seem highly unlikely that a ground wave could possibly cover that distance and further investigations (not by Marconi) led to the discovery of the ionosphere. At the time, it was thought that covering long distances meant lowering the transmit frequency. Marconi was using a 25 kW AC generator operating at about 16 kHz. Such operations were very expensive, not just in the electrical power needed but the substantial antenna system required. It was a surprise to Marconi that raising the frequency was the key to success. For example, he found that a transmitter operating at 3.25 MHz with 12 kW could cover thousands of kilometers of the Earth at night. Further experiments showed that at 20 meters (wavelength), considerably less power could send a radio wave around the world during daylight conditions. Must have been some good sunspots back then. From there, things took off. Marconi was lucky that he seemed to have almost unlimited resources to conduct a variety of experiments. He was persistent at trying different things and adapting when things did not work out. For example, when high winds toppled his original circular array of antenna supports in Poldhu, he came up with something else. He was meticulous at recording his results and devising the next experiment after that. And, when long-distance communication became a commodity, he got rich. Some lessons there.