adventurersclub.dk: Einar Dessau Citat: "...1909 Først radioamatør, der indfangede en transmission, på en selvbygget radio, sammen med Ernst Nyrop. Signalet var Strauss-operetten Karneval i Venedig...", backup
calisphere.org
calisphere.org: Image / Receiver for first amateur radio in the world by Einar Dessau Citat: "...Poulsen Valdimar. Photo. No. 1." "Receiver for first amateur radio in the world, using galena chrystal and graphite point. On right, experimental model (1909). Attempting to make four lead vacuum tube for transmitting." Caption by Douglas Perham, part of a series of pictures from an exhibition regarding "the first amateur station in the world, by Einar Dessau, in Copenhagen, Denmark, in 1907...", backup, billed backup
earlyradiohistory.us: Kilohertz to Meters Conversion Charts Citat: "...The general public, used to wavelengths, had to be coaxed into making the transition to frequencies, and it was a good fifteen years before you stopped seeing references to wavelengths in the U.S. (In Europe, where mediumwave stations are assigned in 9 khz steps, they still are commonly reported by wavelength). In 1923 many publications started to print conversion charts like the two listed above, with explanations about this newfangled frequency concept. However, there was one area of inconsistency, which explains why I've included two slightly different charts...", backup
edr.dk: OZ 05/2007: LytteramatørenArkiveret 21. juli 2017 hos Wayback Machine Citat: "...Åbning af nye kaldesignaler i Danmark/Grønland og Færøerne., efter ansøgning kan der nu i Danmark (OZ) søges om OU-OV-5P og 5Q og for Grønland OX-XP og for Færøerne OY-OW, så nu bliver der nok af nye kaldesignaler at lytte til, SWL manageren har endnu ikke hørt de nye Call. De nye call kan blive udstedt fra første marts 2007, så det skulle ikke være en Aprilsspøg..."
March 18, 2013, infostory.com: First Broadcast by Ham Radio Operator Citat: "...Today in 1909, Einar Dessau of Denmark used a shortwave transmitter to converse with a government radio post about six miles away in what is believed to have been the first broadcast by a ‘ham’ radio operator...", backup
nobelprize.org: Guglielmo Marconi: The Nobel Prize in Physics 1909 Citat: "...on an historic day in December 1901, determined to prove that wireless waves were not affected by the curvature of the Earth, he used his system for transmitting the first wireless signals across the Atlantic between Poldhu, Cornwall, and St. John’s, Newfoundland, a distance of 2100 miles...", backup
adventurersclub.dk: Einar Dessau Citat: "...1909 Først radioamatør, der indfangede en transmission, på en selvbygget radio, sammen med Ernst Nyrop. Signalet var Strauss-operetten Karneval i Venedig...", backup
March 18, 2013, infostory.com: First Broadcast by Ham Radio Operator Citat: "...Today in 1909, Einar Dessau of Denmark used a shortwave transmitter to converse with a government radio post about six miles away in what is believed to have been the first broadcast by a ‘ham’ radio operator...", backup
calisphere.org: Image / Receiver for first amateur radio in the world by Einar Dessau Citat: "...Poulsen Valdimar. Photo. No. 1." "Receiver for first amateur radio in the world, using galena chrystal and graphite point. On right, experimental model (1909). Attempting to make four lead vacuum tube for transmitting." Caption by Douglas Perham, part of a series of pictures from an exhibition regarding "the first amateur station in the world, by Einar Dessau, in Copenhagen, Denmark, in 1907...", backup, billed backup
nobelprize.org: Guglielmo Marconi: The Nobel Prize in Physics 1909 Citat: "...on an historic day in December 1901, determined to prove that wireless waves were not affected by the curvature of the Earth, he used his system for transmitting the first wireless signals across the Atlantic between Poldhu, Cornwall, and St. John’s, Newfoundland, a distance of 2100 miles...", backup
worldradiohistory.com: Broadcast listening in the pioneer days of radio on the short waves, 1923 1945 Jerome S. Berg Citat: "...It is hard to believe today that, until around 1920, virtually all transmitting, by everyone and for all purposes, both short range and long range, was in the frequencies below approximately 1500 kc., or the area that we think of today as the long- and medium- wave bands. This was partly the case because shorter waves were difficult to produce without tubes, which were still in their infancy. It was widely believed that these low frequencies were the only ones of value, and that higher frequency channels, to the extent they could be reached at all, were either worthless for communication purposes or the lairs of technological dragons....The belief that long distance required long wavelengths (that is, low frequencies) was one of the great scientific mistakes of radio's infancy...In addition to having to obtain licenses - a constraint to which they adapted only slowly - the amateurs were, with some exceptions, restricted to the range below 200 meters (that is, above 1500 kc.), bands that were largely unexplored and thought to be of little value. The navy attributed most interference to the amateurs, and was happy to see them on the road to a hoped - for extinction. From the amateurs' point of view, their development of the shortwave spectrum began less as a love affair than a shotgun marriage. However, all that would change...It took several years before experimenters ventured above 2-3 mc. and started to understand such things as shortwave propagation and directionality. The short waves, as they were called, were surrounded with mystery...Also in 1928 Radio News publisher Hugo Gernsback began shortwave broadcasting on 9700 kc. from his station, WRNY, New York, using the call W2XAL. "A reader in New South Wales, Aus- tralia," reported Gernsback, "writes us that while he was writing his letter he was listening to WRNY's short-wave transmitter, 2XAL, on a three-tube set; and had to turn down the volume, otherwise he would wake up his family. All this at a distance of some 10,000 miles! Yet 2XAL ...uses less than 500 watts; a quite negligible amount of power. "6...The 1930s were the golden age of shortwave broadcasting...Shortwave also facilitated communication with people in remote areas. Amateur radio became a basic ingredient of all expeditions...", backup
edr.dk: OZ 05/2007: LytteramatørenArkiveret 21. juli 2017 hos Wayback Machine Citat: "...Åbning af nye kaldesignaler i Danmark/Grønland og Færøerne., efter ansøgning kan der nu i Danmark (OZ) søges om OU-OV-5P og 5Q og for Grønland OX-XP og for Færøerne OY-OW, så nu bliver der nok af nye kaldesignaler at lytte til, SWL manageren har endnu ikke hørt de nye Call. De nye call kan blive udstedt fra første marts 2007, så det skulle ikke være en Aprilsspøg..."
earlyradiohistory.us: Kilohertz to Meters Conversion Charts Citat: "...The general public, used to wavelengths, had to be coaxed into making the transition to frequencies, and it was a good fifteen years before you stopped seeing references to wavelengths in the U.S. (In Europe, where mediumwave stations are assigned in 9 khz steps, they still are commonly reported by wavelength). In 1923 many publications started to print conversion charts like the two listed above, with explanations about this newfangled frequency concept. However, there was one area of inconsistency, which explains why I've included two slightly different charts...", backup
worldradiohistory.com: Broadcast listening in the pioneer days of radio on the short waves, 1923 1945 Jerome S. Berg Citat: "...It is hard to believe today that, until around 1920, virtually all transmitting, by everyone and for all purposes, both short range and long range, was in the frequencies below approximately 1500 kc., or the area that we think of today as the long- and medium- wave bands. This was partly the case because shorter waves were difficult to produce without tubes, which were still in their infancy. It was widely believed that these low frequencies were the only ones of value, and that higher frequency channels, to the extent they could be reached at all, were either worthless for communication purposes or the lairs of technological dragons....The belief that long distance required long wavelengths (that is, low frequencies) was one of the great scientific mistakes of radio's infancy...In addition to having to obtain licenses - a constraint to which they adapted only slowly - the amateurs were, with some exceptions, restricted to the range below 200 meters (that is, above 1500 kc.), bands that were largely unexplored and thought to be of little value. The navy attributed most interference to the amateurs, and was happy to see them on the road to a hoped - for extinction. From the amateurs' point of view, their development of the shortwave spectrum began less as a love affair than a shotgun marriage. However, all that would change...It took several years before experimenters ventured above 2-3 mc. and started to understand such things as shortwave propagation and directionality. The short waves, as they were called, were surrounded with mystery...Also in 1928 Radio News publisher Hugo Gernsback began shortwave broadcasting on 9700 kc. from his station, WRNY, New York, using the call W2XAL. "A reader in New South Wales, Aus- tralia," reported Gernsback, "writes us that while he was writing his letter he was listening to WRNY's short-wave transmitter, 2XAL, on a three-tube set; and had to turn down the volume, otherwise he would wake up his family. All this at a distance of some 10,000 miles! Yet 2XAL ...uses less than 500 watts; a quite negligible amount of power. "6...The 1930s were the golden age of shortwave broadcasting...Shortwave also facilitated communication with people in remote areas. Amateur radio became a basic ingredient of all expeditions...", backup
