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K.W. Electronics was a British manufacturer of amateur radio equipment founded in the mid-1950s by the late Rowley Shears G8KW. It was based in Dartford, Kent, and manufactured a wide range of high frequency band receivers, transmitters and accessory equipment.
The striking cross frame antenna with attached auxiliary antenna can only be found on the signal masts of some older ships because they do not interfere there and dismantling would be too expensive. Modern positioning methods such as GPS, DGPS, radar and the now-outdated Loran C have radio direction finding methods that are imprecise for today ...
A reconfigurable antenna is an antenna capable of modifying its frequency and radiation properties dynamically, in a controlled and reversible manner. [2] In order to provide a dynamic response, reconfigurable antennas integrate an inner mechanism (such as RF switches, varactors, mechanical actuators or tunable materials) that enable the intentional redistribution of the RF currents over the ...
The operator rotated the antenna, looking for points where the signal either reached a maximum or, more commonly, suddenly disappeared or 'nulled'. A common RDF antenna design is the loop antenna, which is simply a loop of wire with a small gap in the circle, typically arranged to rotate around the vertical axis with the gap at the bottom. [3]
The manual frequency provides a common frequency for all members of the network to verify that the equipment is operational. During initial net activation, all operators in the net tune to the manual frequency. After communications are established, the net switches to the FH mode and the NCS transfers the hopping variables to the outstations.
Where radio transmitters and receivers share one antenna, often a coaxial relay is used as a TR (transmit-receive) relay, which switches the antenna from the receiver to the transmitter. This protects the receiver from the high power of the transmitter. Such relays are often used in transceivers which combine transmitter and receiver in one ...
In radar, a transmit/receive (TR) switch alternately connects the transmitter and receiver to a shared antenna. In the simplest arrangement, the switch consists of a gas-discharge tube across the input terminals of the receiver. When the transmitter is active, the resulting high voltage causes the tube to conduct, shorting together the receiver ...
Swan 400 transceiver. Swan’s entry into the amateur radio equipment market consisted of transceivers primarily designed for the newly popular single sideband (SSB) mode of voice transmission, and covered only those portions of the amateur radio bands where SSB could be used.