MORTALITY BY LICENSE CLASS IN AMATEUR RADIO OPERATORS

1988 ◽  
Vol 128 (5) ◽  
pp. 1175-1176 ◽  
Author(s):  
Samuel Milham
Keyword(s):  
IEE Review ◽  
1990 ◽  
Vol 36 (9) ◽  
pp. 338
Author(s):  
Alexander L. Dick
Keyword(s):  

Author(s):  
Gerhard P. Tan ◽  
Jomer V. Catipon ◽  
Patrick Jiorgen U. Hulipas ◽  
Allysa Mae E. Bartolome ◽  
Micah Abegail P. Inosanto ◽  
...  

1951 ◽  
Vol 60 (2) ◽  
pp. 26
Author(s):  
Watson Davis
Keyword(s):  

2021 ◽  
Vol 13 (16) ◽  
pp. 3252
Author(s):  
Gara Quintana-Diaz ◽  
Torbjörn Ekman ◽  
José Miguel Lago Agra ◽  
Diego Hurtado de Mendoza ◽  
Alberto González Muíño ◽  
...  

Radio interference in the uplink makes communication to satellites in the UHF amateur radio band (430–440 MHz) challenging for any satellite application. Interference measurements and characterisation can improve the robustness and reliability of the communication system design. Most published results focus on average power spectrum measurements and heatmaps. We apply a low complexity estimator on an SDR (Software-Defined Radio) to study the interference’s dispersion and temporal variation on-board a small satellite as an alternative. Measuring the Local Mean Envelope (LME) variability with different averaging window lengths enables the estimation of time variability of the interference. The coefficient of variation for the LME indicates how much the signals vary in time and the spread in magnitudes. In this article, theoretical analysis, simulations, and laboratory results were used to validate this measurement method. In-orbit measurements were performed on-board the LUME-1 satellite. Band-limited interference with pulsed temporal behaviour and a high coefficient of variation was detected over North America, Europe, and the Arctic, where space-tracking radars are located. Wide-band pulsed interference with high time variability was also detected over Europe. These measurements show why operators that use a communication system designed for Additive White Gaussian Noise (AWGN) at power levels obtained from heatmaps struggle to command their satellites.


2015 ◽  
Vol 3 (4) ◽  
pp. 155-165
Author(s):  
Phil Wait

Scratch any older electronics or telecommunications professional and there’s a good chance you’ll find an Amateur Radio operator. Amateur Radio operators of our fathers or grandfathers era typically set-up transmitting stations in sheds down the backyard with wire antennas strung between the trees. Talking to people around the world on HF amateur bands was cool then, as even a phone call interstate was tricky; you needed to book a time with the telephone trunk operator, and it cost a small fortune. The more adventurous amateurs experimented with frequencies above 30MHz, and many pushed the limits of the available technology. In 1947, an Australian amateur (VK5KL) made a two-way contact on 50MHz with an amateur in Hawaii (W7ACS/KH6), a path of 9000 km. That was esoteric stuff - how times have changed!


Author(s):  
Sukkharak Sae-Chia ◽  
Apiwat Magkeethum ◽  
Paramote Wardkein

Author(s):  
Alejandra Bronfman

Picking up in the early 1920s, this chapter tracks the shift of radio technology from military to commercial uses. It follows linkages among the changing material conditions for Caribbean workers, the radio industry’s search for materials like mica and bakelite, and the generation of new markets. Having placed broadcasting in its ecological and political contexts, the chapter uses the trajectories of two amateur radio operators, John Grinan, a New Yorker/Jamaican son of a plantation owner and a member of the team which produced the first transatlantic wireless signals, and Frank Jones, an American plantation manager in Cuba, famous for his self-promoting shortwave transmissions to recover the world of the tinkerers’ romance with an ether jammed with distant sounds. It traces the creation of audiences and publics for the emerging technology, arguing that radio appealed to listeners not because it shrank distances, but because it underscored them, demarcating the Caribbean as exotic and remote. Ironically, it was the deeper technological connections that would propel the mapping of these imagined boundaries between the “tropics” and “the world.”


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