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Diagram of leaky feeder cable. A leaky feeder is a communications system used in underground mines and inside tunnels. [1] Manufacturers and cabling professionals use the term "radiating cable" [2] [3] [better source needed] [4] as this implies that the cable is designed to radiate: something that a typical coaxial cable is generally not intended to do.
An RF connector (radio frequency connector) is an electrical connector designed to work at radio frequencies in the multi-megahertz range. RF connectors are typically used with coaxial cables and are designed to maintain the shielding that the coaxial design offers.
The cable has a characteristic impedance of 75 ohms, and a capacitance of around 20pF/ft (60pF/m). [1] The 75 ohm impedance matches a dipole antenna in free space. RG (for radio guide ) was originally a unit indicator for bulk radio frequency (RF) cable in the U.S. military's Joint Electronics Type Designation System .
Cross-section through a coaxial cable showing shielding and other layers. One example is a shielded cable, which has electromagnetic shielding in the form of a wire mesh surrounding an inner core conductor. The shielding impedes the escape of any signal from the core conductor, and also prevents signals from being added to the core conductor.
In a radio antenna, the feed line (feedline), or feeder, is the cable or other transmission line that connects the antenna with the radio transmitter or receiver.In a transmitting antenna, it feeds the radio frequency (RF) current from the transmitter to the antenna, where the energy in the current is radiated as radio waves.
BNC is designed to maintain the characteristic impedance of the cable across the connection, and is made in 50-ohm and 75-ohm versions. It is normally used for radio-frequency signals up to about 2 gigahertz and 500 volts. Similar radio-frequency connectors differ in dimensions and attachment features, and may allow for higher voltages, higher ...
Several online retailers and drone technology companies are marketing the sale of radio frequency jammers as drone deterrence or privacy tools, sidestepping federal laws that prohibit such devices ...
A grid leak resistor and capacitor unit from 1926. The 2 megohm cartridge resistor is replaceable so the user can try different values. The parallel capacitor is built into the holder. A grid leak detector is an electronic circuit that demodulates an amplitude modulated alternating current and amplifies the recovered modulating voltage. The ...