Ad
related to: cb vs gmrs ham antenna diagram explained
Search results
Results From The WOW.Com Content Network
The antenna may not be more than 20 feet (6.1 m) above the highest point of the structure it is mounted to, or the highest point of the antenna must not be more than 60 feet (18.3 m) above the ground (47 CFR 95.408(c)) if installed in a fixed location. [4] CB radios must include AM or SSB modulation and may include frequency modulation. [5]
An unsuccessful petition was filed in 1973 to create a CB Class E service at 220 MHz, (part of the amateur radio 1.25-meter band at the time) which was opposed by amateur radio organizations and others. [6] There are several other classes of personal radio services for specialized purposes (such as remote control devices).
The category of simple antennas consists of dipoles, monopoles, and loop antennas. Nearly all can be made with a single segment of wire (ignoring the break made in the wire for the feedline connection). [citation needed] Dipoles and monopoles called linear antennas (or straight wire antennas) since their radiating parts lie along a single ...
As with FRS/GMRS and PMR446, the use of tone squelch systems such as CTCSS/DCS is encouraged. Like the PMR446, LPD433, Japan's 421–422 MHz SLPR service and KDR444 services, use of these frequencies in countries such as the United States is illegal without an amateur radio license as they fall within the 420–450 MHz 70 cm ham radio allocation.
TIDRADIO TD-H5 GMRS radios. The General Mobile Radio Service (GMRS) is a land-mobile FM UHF radio service designed for short-range two-way voice communication and authorized under part 95 of the US FCC code. It requires a license in the United States, but some GMRS compatible equipment can be used license-free in Canada. The US GMRS license is ...
The J-pole antenna is an end-fed omnidirectional half-wave antenna that is matched to the feedline by a shorted quarter-wave parallel transmission line stub. [5] [1] [6] For a transmitting antenna to operate efficiently, absorbing all the power provided by its feedline, the antenna must be impedance matched to the line; it must have a resistance equal to the feedline's characteristic impedance.
Counterpoises are typically used in antenna systems for radio transmitters where a good earth ground connection cannot be constructed.. Monopole antennas used at low frequencies, below 3 MHz, such as the mast radiator antennas used for AM broadcasting, require the radio transmitter to be electrically connected to the Earth under the antenna; this is called a ground (or earth).
Patch antenna gain pattern. A directional antenna or beam antenna is an antenna which radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain direction is desired, or in receiving antennas receive radio waves from one specific direction only.