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Most radio propagation beacons use amateur radio frequencies. They can be found on LF, MF, HF, VHF, UHF, and microwave frequencies. Microwave beacons are also used as signal sources to test and calibrate antennas and receivers. [1] [2]
Pages in category "Lists of radio stations by frequency" The following 200 pages are in this category, out of approximately 338 total. This list may not reflect recent changes .
The list of frequency ranges is called a band allocation, which may be set by international agreements, and national regulations. The modes and types of allocations within each frequency band is called a bandplan ; it may be determined by regulation, but most typically is set by agreements between amateur radio operators.
In its most widely used form, APRS is transported over the AX.25 protocol using 1,200-bit/s Bell 202 AFSK on frequencies located within the 2-meter amateur band. Sample APRS VHF frequencies. 144.39 MHz : North America, Colombia, Chile, Indonesia, Malaysia, Singapore, Thailand; 144.575 MHz : New Zealand [10] [11] 144.64 MHz : China, [12] Taiwan
For the U.S., a form of clear channels first appeared in 1923 when the Commerce Department started moving stations which had previously shared three [6] (initially two) [7] frequencies (two for entertainment stations, one for "weather and crop reports") onto a band of frequencies from 550 to 1350 kHz, [8] which was later extended to 1500 kHz ...
Open spectrum (also known as free spectrum) is a movement to get the Federal Communications Commission to provide more unlicensed radio-frequency spectrum that is available for use by all.
The Time Frequency Codes (TFC) define the frequency interleaving sequence for utilizing 1-3 of the bands within a band group. TFCs 1-4 are for TFI channels, TFCs 5-7 are for FFI channels, and TFCs 8-10 are for TFI2 channels, which simply interleave their data across two bands.
These charts also list other frequencies that are not specifically part of the "business band" but are commonly used by businesses. An individual license is still required under GMRS rules. A few manufacturers added these DOT frequencies to Business radios in the 1990s to have more "channels" and aid in selling radios.