Radio Antenna Fundamentals
Part 1
Part 2
Antenna Fundamentals - Propagation
Radio Antenna Fundamentals
Part 1
Part 2
Antenna Fundamentals - Propagation
Lack of preventive maintenance or excessive load of instruments into the gondola?
We recently received this Asian Disaster Management News from Academia.edu
The new model GSB 9000 DX is also available.
Rick - I2BCF
Archivio Nazionale Cinema d'Impresa
di Filippo Paolone
Visita a una Centrale Telefonica Pubblica (anni '38)
Giornale Luce B1233 del 12/01/1938 Descrizione sequenze: visione di una palazzina dove ha sede una grande centrale telefonica ; la stazione d'energia che alimenta la centrale ; il grande salone dell'autocommutatore ; i quadri selettori e preselettori che entrano in funzione quando un utente seleziona una chiamata ; il distributore delle chiamate ; la centrale interurbana ; l'operatrice mentre compila il cartellino che poi affida al nastro trasportatore ; il tavolo di smistamento della posta pneumatica ; le operatrici della centrale interurbana durante il proprio lavoro ; il sistema di fili metallici raggiungono anche le alte vette montuose ; il servizio speciale urbano con le varie operatrici in funzione ; il reparto fonotelegrammi nel pieno della sua attività.
Istituto Luce Cinecittà: tutte le immagini e i fotogrammi più belli di come eravamo, rivissuti attraverso i film, i documentari e i video che hanno fatto la storia del nostro Paese.
In this episode of the Voices from DARPA podcast, John Waterston, a program manager since 2017 in the agency's Strategic Technology Office, lets listeners in on his oceanic immersions both as a naval officer and a technology developer. Now a commander in the U.S. Naval Reserves, John offers snapshots of living, working, and serving on our nation's nuclear submarines before describing his current work at DARPA to develop technologies to better understand, monitor, and navigate the planet's most prevalent environment-the oceans. In one of his ambitious programs, John seeks to deliver what has been a coveted but elusive capability-the equivalent of GPS that operates even in the deep ocean. In a related program, John explains how very low-frequency (VLF) electromagnetic signals from lightning that occurs relentlessly around the world can become a key to a back-up positioning, navigation, and timing (PNT) system in case our must-have GPS goes down.
Tad Cook, K7RA, Seattle, reports: We just witnessed 12 consecutive days with no sunspots, which many of us found a bit unsettling. Fortunately, Solar Cycle 25 activity returned with new sunspot 2796 on January 15. Instead of moving from the east across the solar horizon, it emerged in the southern hemisphere, just west of center.
Currently we are seeing sunspot regions 2797 and 2798, which emerg...
A derecho with winds of 80 to 100 MPH struck eastern Iowa last August, disrupting power and telecommunications for some 400,000 residents. But, asARRL member and Amateur Radio Emergency Service (ARES®) volunteer Scott Haney, N0GUD, recently explained to The Gazette in Cedar Rapids, that’s when amateur radio shines.
Haney, the president of the Cedar Valley Amateur Radio Club (CVARC), was the foc...
Contest University (CTU) is holding a Virtual Propagation Summit on Saturday, January 23. The Zoom-platform event will get under way with introductory remarks from Tim Duffy, K3LR, and Ray Novak, N9JA, at 1600 UTC.
At 1605 UTC, Scott Jones, N3RA, and George Fremin, K5TR, will moderate a session “Update on the Personal Space Weather Station Project & HamSCI activities for 2021” with Nathaniel Fri...
