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Wireless Set No. 10 – 8 channel multiplexed microwave transmitter/receiver. [4] Wireless Set No. 11 – Replacement for No. 1. Used by the likes of the Long Range Desert Group during WW2. Replaced by No. 19. Wireless Set No. 12 – Static or vehicle mounted transmitter station, range about 60 miles (~96 km). Wireless Set No. 17 – 2-valves ...
The AN/PRC-77 entered service in 1968 during the Vietnam War as an upgrade to the earlier AN/PRC-25.It differs from its predecessor mainly in that the PRC-77's final power amplifier stage is made with a transistor, eliminating the only vacuum tube in the PRC-25, as well as the DC-DC voltage converter used to create the high plate voltage for the tube from the 15 V battery.
Electrical codes require such exposed high voltage equipment to be fenced off from the public, so the mast and antenna tuning hut are surrounded by a locked fence. Usually a chain-link fence is used, but sometimes wooden fences are used to prevent currents induced in a metallic fence from distorting the radiation pattern of the antenna. An ...
A practical spark gap transmitter consists of these parts: [11] [13] [14] [15] A high-voltage transformer, to transform the low-voltage electricity from the power source, a battery or electric outlet, to a high enough voltage (from a few kilovolts to 75-100 kilovolts in powerful transmitters) to jump across the spark gap. The transformer ...
In wireless communications, channel state information (CSI) is the known channel properties of a communication link.This information describes how a signal propagates from the transmitter to the receiver and represents the combined effect of, for example, scattering, fading, and power decay with distance.
E.F. Johnson Museum, Waseca, Minnesota EF Johnson Citizen Band walkie-talkie The company was founded in 1923 by Edgar F. Johnson and his wife Ethel Johnson. The company began as a mail order business, selling radio transmitting parts to amateurs and early radio broadcasters from space shared with a woodworking shop located in downtown Waseca.
In a single receiver residential installation there is a single coaxial cable running from the receiver set-top box in the building to the LNB on the dish. The DC electric power for the LNB is provided through the same coaxial cable conductors that carry the signal to the receiver.
This allows more types of data to be broadcast, including video and encrypted communication, which is commonly used by police and fire departments. Digital transmissions tend to be clearer and more detailed than their analog counterparts. Many modern wireless devices operate on digital transmissions.