Some basics. Cavity filters are the basic circuitry behind a Duplexer and are sharply tuned resonant circuit that allow only certain frequencies to pass. Generically, filter of this kind are known as notch filters. Physically a cavity filter is a resonator inside a conducting “box” with coupling loops at the input and output, as follows:
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“Our inflatable antenna/video towers let you quickly put up antennas and/or video packages to extend or reinforce your coverage in a range of situations. There are several models and sizes available with an assortment of
Seven good ideas for amateur radio operators forced due to space restrictions, to operate on HF and VHF ham radio bands from apartments with heavy antenna …
VE3SQB ANTENNA DESIGN PROGRAMS EN82NE. Antenna Design Programs–With surface mount technology and microcircuitry, most …
The Amateur Radio Relay Group – ARRG – K7RPT Repeater System Affiliated with American Radio Relay League (ARRL).
Amateur radio satellites can be accessed, some using a hand-held transceiver (), even, at times, using the factory “rubber duck” antenna. Hams also use the moon, the aurora borealis, and the ionized trails of meteors as reflectors of radio waves. Hams can also contact the International Space Station (ISS) because many astronauts and cosmonauts are licensed as amateur radio …
Stormy weather over the weekend took down two major ham radio antenna towers in Finland and in Denmark. On December 6, Radio Arcala (OH8X) reported that its 330 foot tall tower near the village of Arkala that supported 160 meter and 80 meter Yagis literally fell victim to high winds that also took
Radio masts and towers are, typically, tall structures designed to support antennas (also known as aerials) for telecommunications and broadcasting, including television.There are two main types: guyed and self-supporting structures. They are among the tallest man-made structures. Masts are often named after the broadcasting …
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