User:Thornfield Hall/Radio

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  MF
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  HF
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  Comparison of the frequency bands defined by NATO, IEEE and ITU
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  FRS and GMRS frequency spectrum usage, including bandwidth and maximum power allowances.
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  A schematic showing the relationship between dBu (the voltage source) and dBm (the power dissipated as heat by the 600 Ω resistor)
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  Animation showing a half-wave dipole antenna receiving power from a radio wave. The antenna consists of two metal rods each one-quarter of the wavelength long, attached through a parallel transmission line to a resistance R equal to the characteristic impedance of the antenna, representing the receiver. The electromagnetic wave is represented by its electric field (E, green arrows) (it should be kept in mind that the drawing only shows the field along one line, while the radio wave is actually a plane wave and the electric field is actually the same at every point on a plane perpendicular to the direction of motion). The wave's magnetic field is not shown. The oscillating electric field exerts force on the electrons in the antenna rods , causing them to move back and forth in currents (black arrows) between the ends of the antenna rods, charging the ends of the antenna alternately positive (+) and negative (−). Since the antenna is a half-wavelength long at the radio wave's frequency, it excites standing waves of voltage (V, red) and current in the antenna. The voltage along the antenna elements is represented graphically by a band of red whose thickness at any point is proportional to the magnitude of the voltage. The oscillating currents flowing back and forth from one antenna element to the other, pass down the transmission line and through the radio receiver, represented by R. In this animation the action is shown slowed down drastically; the radio waves received by dipoles actually oscillate back and forth at tens of thousands to billions of cycles per second.
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  Animation showing standing waves on a half-wave dipole antenna driven by a sinusoidal voltage Vi from a radio transmitter at its resonant frequency. The oscillating voltage pushes the electrons back and forth along the two metal rods that make up the antenna, creating oscillating currents (blue arrows) in the antenna, charging its ends alternately positive (+) and negative (-). Since at this frequency the antenna is a half wavelength (λ/2) long, a sinusoidal wave of voltage or current takes exactly one cycle to make the round trip from one end of the antenna to the other and back, so the reflected waves reinforce each other. The antenna acts like an electronic resonater. Waves of current and voltage reflecting back and forth between the ends of the rods interfere to form standing waves, which radiate radio waves into space. The waves are shown graphically by bars of color (red for voltage V(x) and blue for current I(x)) whose width at each point is proportional to the amplitude of the wave at that point. The blue arrows show the direction of conventional current, flow of positive charge. The electrons oscillating back and forth in the antenne move in a direction opposite to the arrows. The action is shown slowed down enormously; the currents in an actual antenna oscillate back and forth 20 thousand to one billion times per second.
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  Animation of a half-wave dipole antenna transmitting radio waves, showing the electric field lines. The dipole, in the center, consists of two vertical metal rods with an alternating current at its resonant frequency applied at its center from a radio transmitter (not shown) The voltage alternately charges the two ends of the antenna positive (+) and negative (−). Standing waves of current (red arrows) flow up and down the rods. The alternating voltage on the rods creates loops of electric field (black lines) that pinch off into closed loops and radiate away from the antenna at the speed of light. These are the radio waves. The radiated power is greatest in the horizontal direction, perpendicular to the antenna, and decreases to zero above and below the antenna, on the antenna axis. This picture only shows the electric field in a single plane through the antenna axis; the field is actually axially symmetrical about the antenna. The action is shown slowed down drastically in this animation; real radio waves oscillate at rates of thirty thousand to a billion cycles per second.
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  Animation showing how a Yagi-Uda antenna works. It consists of 4 half-wave dipole antennas in a line; a driven element (E) which is connected to the transmitter and radiates the radio waves, and 3 parasitic elements, two directors (D1, D2) and one reflector (R) which act as resonators, absorbing and reradiating the waves from the driven element with a different phase. The radio waves from all 4 elements combine and interfere, increasing the power radiated in the desired direction (up) and decreasing the power radiated in other directions. The radio waves from each individual element (wavy moving lines) are shown in a different color. The waves in the forward direction are in phase, and interfere constructively, adding together to produce a higher signal strength, while the waves in the reverse direction are out of phase, partially canceling each other to produce lower signal strength in that direction.
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  Schematics of a simple Yagi-Uda antenna with just a driven dipole and a director and their emitted fields
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  Diagram of ground dipole antenna used to transmit extremely low frequency (ELF) radio waves, showing how it works. This is modeled on the U.S. Navy ELF radio transmitter at Clam Lake, Wisconsin, which was used to communicate with submerged submarines at a frequency of 76 Hz from 1989 to 2004. The antenna consists of two electrodes buried in the Earth (G), 14 miles (23.5 km) apart, linked by overhead transmission lines resembling ordinary power distribution lines to a power plant transmitter (P). The system functions as a giant vertical loop antenna in which the earth serves as part of the loop. The power plant drives the antenna with 300 amperes alternating current at 76 Hz which flows through one transmission line, in looping currents (I) deep in bedrock from one ground electrode to the other, and back through the other transmission line (the drawing shows only one direction of the alternating current). The AC current creates an alternating magnetic field (H) which radiates ELF waves (yellow). The radiation pattern is directional, with two lobes (maxima) off the ends of the wire.
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  Typical spectrum of extremely low frequency (ELF) electromagnetic oscillations in the Earth's atmosphere, showing peaks caused by the Schumann resonances. The Schuman resonances are the resonant frequencies of the spherical cavity bounded by the Earth and the ionosphere; lighning strikes and other sferics cause the Earth-ionosphere cavity to "ring" like a bell at these frequencies, causing peaks in the noise spectrum. The sharp power peak at 50 Hz is caused by radiation from global electric power grids. The rise of the noise at low frequencies (left side) is radio noise caused by slow processes in the Earth's magnetosphere.

Band name	Abbreviation	ITU band number	Frequency and wavelength	Example uses
Extremely low frequency	ELF	1	3–30 Hz 100,000–10,000 km	Communication with submarines
Super low frequency	SLF	2	30–300 Hz 10,000–1,000 km	Communication with submarines
Ultra low frequency	ULF	3	300–3,000 Hz 1,000–100 km	Communication with submarines, communication within mines, landline telephony, fax machines, fiber-optic communication
Very low frequency	VLF	4	3–30 kHz 100–10 km	Navigation, time signals, communication with submarines, landline telephony, wireless heart rate monitors, geophysics
Low frequency	LF	5	30–300 kHz 10–1 km	Navigation, time signals, AM longwave broadcasting (Europe and parts of Asia), RFID, amateur radio.
Medium frequency	MF	6	300–3,000 kHz 1,000–100 m	AM (medium-wave) broadcasts, amateur radio, avalanche beacons, magnetic resonance imaging, positron emission tomography, electrical telegraph, wireless telegraphy, radioteletype, dial-up internet.
High frequency	HF	7	3–30 MHz 100–10 m	Shortwave broadcasts, citizens band radio, amateur radio, over-the-horizon aviation communications, RFID, over-the-horizon radar, automatic link establishment (ALE) / near-vertical incidence skywave (NVIS) radio communications, marine and mobile radio telephony, CT scan, magnetic resonance imaging, positron emission tomography, ultrasound, cordless phones.
Very high frequency	VHF	8	30–300 MHz 10–1 m	FM broadcasts, television broadcasts, cable television broadcasting, radars, line-of-sight ground-to-aircraft, aircraft-to-aircraft communications, emergency locator beacon homing signal, radioteletype, land mobile and maritime mobile communications, amateur radio, police, fire and emergency medical services scanners, weather radio, CT scan, magnetic resonance imaging, positron emission tomography, ultrasound, cordless phones.
Ultra high frequency	UHF	9	300–3,000 MHz 100–10 cm	Television broadcasts, cable television broadcasting, microwave oven, radars, microwave devices/communications, radio astronomy, radars (L band), mobile phones, wireless LAN, Bluetooth, Zigbee, GPS and two-way radios such as land mobile, emergency locator beacon, FRS and GMRS radios, amateur radio, satellite radio, police, fire and emergency medical services scanners, remote control systems, ADSB, cordless phones, internet, dial-up internet, satellite broadcasting, communication satellites, weather satellites, satellite phones (L band), satellite phones (S band).
Super high frequency	SHF	10	3–30 GHz 10–1 cm	Radio astronomy, microwave devices/communications, wireless LAN, DSRC, most modern radars, communications satellites, cable and satellite television broadcasting, DBS, amateur radio, satellite broadcasting, communication satellites, weather satellites, satellite radio, cordless phones, internet, satellite phones (S band).
Extremely high frequency	EHF	11	30–300 GHz 10–1 mm	Radio astronomy, satellite broadcasting, communication satellites, weather satellites, high-frequency microwave radio relay, microwave remote sensing, directed-energy weapon, millimeter wave scanner, Wireless Lan 802.11ad, internet.
Terahertz or tremendously high frequency	THF	12	300–3,000 GHz 1–0.1 mm	Experimental medical imaging to replace X-rays, ultrafast molecular dynamics, condensed-matter physics, terahertz time-domain spectroscopy, terahertz computing/communications, remote sensing

GMRS Frequency table

Frequency	Channel	FRS power	FRS bandwidth	GMRS power	GMRS bandwidth	Notes
462.5625 MHz	1	2 W	12.5 kHz	5 W	20 kHz	(1)(4)(5)
462.5875 MHz	2	2 W	12.5 kHz	5 W	20 kHz	(1)(4)(5)
462.6125 MHz	3	2 W	12.5 kHz	5 W	20 kHz	(1)(4)(5)
462.6375 MHz	4	2 W	12.5 kHz	5 W	20 kHz	(1)(4)(5)
462.6625 MHz	5	2 W	12.5 kHz	5 W	20 kHz	(1)(4)(5)
462.6875 MHz	6	2 W	12.5 kHz	5 W	20 kHz	(1)(4)(5)
462.7125 MHz	7	2 W	12.5 kHz	5 W	20 kHz	(1)(4)(5)
467.5625 MHz	8	0.5 W	12.5 kHz	0.5 W	12.5 kHz	(1)(4)(6)
467.5875 MHz	9	0.5 W	12.5 kHz	0.5 W	12.5 kHz	(1)(4)(6)
467.6125 MHz	10	0.5 W	12.5 kHz	0.5 W	12.5 kHz	(1)(4)(6)
467.6375 MHz	11	0.5 W	12.5 kHz	0.5 W	12.5 kHz	(1)(4)(6)
467.6625 MHz	12	0.5 W	12.5 kHz	0.5 W	12.5 kHz	(1)(4)(6)
467.6875 MHz	13	0.5 W	12.5 kHz	0.5 W	12.5 kHz	(1)(4)(6)
467.7125 MHz	14	0.5 W	12.5 kHz	0.5 W	12.5 kHz	(1)(4)(6)
462.5500 MHz	15	2 W	12.5 kHz	50 W	20 kHz	(2)(5)
462.5750 MHz	16	2 W	12.5 kHz	50 W	20 kHz	(2)(5)
462.6000 MHz	17	2 W	12.5 kHz	50 W	20 kHz	(2)(5)
462.6250 MHz	18	2 W	12.5 kHz	50 W	20 kHz	(2)(5)
462.6500 MHz	19	2 W	12.5 kHz	50 W	20 kHz	(2)(5)
462.6750 MHz	20	2 W	12.5 kHz	50 W	20 kHz	(2)(5)(7)
462.7000 MHz	21	2 W	12.5 kHz	50 W	20 kHz	(2)(5)
462.7250 MHz	22	2 W	12.5 kHz	50 W	20 kHz	(2)(5)
467.5500 MHz	15R	—N/a	—N/a	50 W	20 kHz	(3)(5)
467.5750 MHz	16R	—N/a	—N/a	50 W	20 kHz	(3)(5)
467.6000 MHz	17R	—N/a	—N/a	50 W	20 kHz	(3)(5)
467.6250 MHz	18R	—N/a	—N/a	50 W	20 kHz	(3)(5)
467.6500 MHz	19R	—N/a	—N/a	50 W	20 kHz	(3)(5)
467.6750 MHz	20R	—N/a	—N/a	50 W	20 kHz	(3)(5)
467.7000 MHz	21R	—N/a	—N/a	50 W	20 kHz	(3)(5)
467.7250 MHz	22R	—N/a	—N/a	50 W	20 kHz	(3)(5)

Table notes

(1) Shared FRS and GMRS simplex.
(2) Shared FRS and GMRS simplex; GMRS repeater output.
(3) GMRS repeater input. The output frequency of this repeater input is the input frequency minus 5 MHz.
(4) FRS transmissions are limited to bandwidth of 11 kHz with a transmitter deviation of +/- 2.5 kHz. Channels are on 12.5 kHz centers.
(5) GMRS transmissions may have a bandwidth of 16 kHz with a transmitter deviation of +/- 5.0 kHz. Channels are on 25 kHz centers.
(6) GMRS transmissions are limited to a bandwidth of 11 kHz with a transmitter deviation of +/- 2.5 kHz. Channels are on 12.5 kHz centers.
(7) National GMRS calling channel (CTCSS tone 141.3 Hz).

MURS

Channel	Frequency	Maximum authorized bandwidth	Channel name
1	151.82 MHz	11.25 kHz	MURS 1
2	151.88 MHz	11.25 kHz	MURS 2
3	151.94 MHz	11.25 kHz	MURS 3
4	154.57 MHz	20.00 kHz	Blue Dot
5	154.60 MHz	20.00 kHz	Green Dot

Marine VHF

A marine VHF set is a combined transmitter and receiver and only operates on standard, international frequencies known as channels. Channel 16 (156.8 MHz) is the international calling and distress channel. Transmission power ranges between 1 and 25 watts, giving a maximum range of up to about 60 nautical miles (111 km) between aerials mounted on tall ships and hills, and 5 nautical miles (9 km; 6 mi) between aerials mounted on small boats at sea level. Frequency modulation (FM) is used, with vertical polarization, meaning that antennas have to be vertical in order to have good reception. For longer range communication at sea, marine MF and marine HF bands and satellite phones can be used.

Half-duplex channels here are listed with the A and B frequencies the same. The frequencies, channels, and some of their purposes are governed by the ITU. For an authoritative list see. The original allocation of channels consisted of only channels 1 to 28 with 50 kHz spacing between channels, and the second frequency for full-duplex operation 4.6 MHz higher.

Improvements in radio technology later meant that the channel spacing could be reduced to 25 kHz with channels 60 to 88 interspersed between the original channels.

Channels 75 and 76 are omitted as they are either side of the calling and distress channel 16, acting as guard channels. The frequencies which would have been the second frequencies on half-duplex channels are not used for marine purposes and can be used for other purposes that vary by country. For example, 161.000 to 161.450 MHz are part of the allocation to the Association of American Railroads channels used by railways in the US and Canada.

Channel number	Frequencies (MHz)		United Kingdom	United States	Canada	Australia	New Zealand	Finland	Europe CEPT Mediterranean countries (sea, ocean)	Belgium France Germany Netherlands CCNR: main stem, river, canal, lake, pond, estuary
	A  Ship tx, usually	B  Shore tx, usually
0	156.000	160.600	Private, coast guard  A
1	156.050	160.650		Ship-to-ship/shore, commercial and safety West Coast  A	Public Correspondence (Ship-to-Shore full-duplex) BC Coast			Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways.. (Ship-to-Shore full-duplex)
2	156.100	160.700			Public BC Coast			Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways.. (Ship-to-Shore full-duplex)
3	156.150	160.750		A  Illegal for public use	Public BC Coast/Inland		Boat to Boat - Kawau	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks, Customs Coast Guard, search and rescue	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways. (Ship-to-Shore full-duplex)
4	156.200	160.800			Ship-to-ship/shore, commercial and safety East Coast and Inland  A  Canadian Coast Guard - public working channel BC Coast  A		Boat to Boat - Tutukaka/Raglan	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks, Customs Coast Guard, search and rescue	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks
5	156.250	160.850			Ship Movements			Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks, authorities responsible	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways.. (Ship-to-Shore full-duplex)
6	156.300	156.300	Ship-to-ship + Ship-to-Air  A		Ship-to-ship + Ship-to-Air  A	Distress - Ship-to-Air	Working - Internship	A  Ship-to-ship (commercial) also SAR: Ship-to-Ship + Ship-to-Air	Ship-to-ship + Ship-to-Air  A	Ship-to-ship (limited to 1 watt) + Ship-to-Air
7	156.350	160.950			General working channel			Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Navy	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways.. (Ship-to-Shore full-duplex)
8	156.400	156.400	Ship-to-ship  A		Ship-to-ship East and west coasts, Lake Winnipeg  A	Working - Internship	Working - Internship	A  Ship-to-ship (commercial)	A  Ship-to-ship	A  Ship-to-ship (limited to 1 watt)
9	156.450	156.450	Frequently used by pilots  A	Calling  A , commercial and non-commercial.	Ship-to-air for maritime support Atlantic and BC coasts  A	Pilots, Port Operations	Port Operations	A  VTS Ship-to-ship + Port Operations	Marina pilots, Marina Operations, Ship in a marina	Marina pilots, Marina Operations, Ship in a marina (limited to 1 watt)
10	156.500	156.500	Frequently used by HM Coastguard  A		Ship-to-air - SAR and antipollution  A  General working - Atlantic and BC coasts, Great Lakes		Port Operations	A  Ship-to-ship Port Operations also SAR and oil cleanup only VTS on Gulf of Finland	International waters Ship-to-ship ; Customs Coast Guard, Navy	Calling ; Ship-to-ship ; Customs, On board working (limited to 1 watt) Distress, safety and calling
11	156.550	156.550	Port Operations		VTS - BC Coast Pilotage  A		Port Operations	A  Port Operations, also the Saimaa Canal locks	Navy	Port Operations
12	156.600	156.600	Port Operations	VTS - San Francisco offshore Pilotage  A	VTS - BC Coast Port and pilot ops  A	Port Operations, VTS	Port Operations	A  Port Operations	Commercial port operations, fishing port operations, pilots, Ship in a fishing port, Ship in a Commercial port
13	156.650	156.650	Bridge-to-Bridge Working  A	Bridge-to-Bridge safety  A : Vessels > 20m must maintain watch, Tx limited to 1 watt. Movable bridge / lock operations.	VTS - BC Coast Bridge-to-bridge safety  A	Port Operations, VTS	Internship Nav Safety	A  Pilots Ship-to-ship Port Operations	Port Operations, Coast Guard	Ship-to-ship (limited to 1 watt)
14	156.700	156.700	Port Operations	VTS - San Francisco Bay and Delta Pilotage  A	VTS - BC Coast Port and pilot ops  A		Port Operations	A  Working channel for SAR authorities, Turku Radio (Port Operations)	Port Operations, Navy	Port Operations
15	156.750	156.750	On board working (limited to 1 watt)  A					A  max 1 W Intraship Ship-to-ship Port Operations	beach monitoring	Radiocommunications on board a ship or in a group of boats towed or pushed, as well as those concerning the instructions for the maneuver bullish and docking. (limited to 1 watt)
16	156.800	156.800	International distress, safety and calling  A  All vessels equipped with VHF must maintain watch.							Estuary (16 + 10). Not used on: Main stem, River, Canal, Lake, Pond.
17	156.850	156.850	On board Working  A				Aquatic Sports Events	A  max 1 W Intraship Ship-to-ship Port Operations	Port Operations, Navy, Maritime Gendarmerie	Radiocommunications on board a ship or in a group of boats towed or pushed, as well as those concerning the instructions for the maneuver bullish and docking. (limited to 1 watt)
18	156.900	161.500						Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
19	156.950	161.550		Landside facilities: harbormaster, marinas.	Canadian Coast Guard - Working Channel			Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
20	157.000	161.600				Repeater Operations	Continuous Weather Maritime Safety Service	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Port Operations, Public Correspondence (Ship-to-Shore full-duplex)	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex), (limited to 1 watt Paris Underground canal)
21	157.050	161.650		A  U.S. Coast Guard Only	Continuous marine broadcasts  B  (WX 8)		Continuous Weather Maritime Safety Service	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Port Operations
22	157.100	161.700		A  U.S. Coast Guard—public working channel			Continuous Weather Maritime Safety Service	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Port Operations, Public Correspondence (Ship-to-Shore full-duplex)	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
23	157.150	161.750	HM Coastguard Maritime Safety Information - Now on 62,63,64	A  U.S. Coast Guard Only			Continuous Weather Maritime Safety Service	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Port Operations, Public Correspondence (Ship-to-Shore full-duplex)	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex), Independent radio networks
24	157.200	161.800	UKSAR G/A Winching  A  UKSAR TWC  B					Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
25	157.250	161.850					Maritime Radio Working Channel	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
26	157.300	161.900	HM Coastguard Maritime Safety Information	Public correspondence (marine telephone operator)				Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
27	157.350	161.950						Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
28	157.400	162.000						Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
31	157.550	162.150								(The Netherlands) Marina channel Public Correspondence (Ship-to-Shore full-duplex)
M1/37A	157.850	157.850	(As M1) Yacht clubs, race committees and marinas
60	156.025	160.625						GOFREP on Gulf of Finland Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
61	156.075	160.675		A  Illegal for public use				GOFREP (Estonia) on Gulf of Finland Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
62	156.125	160.725	HM Coastguard Maritime Safety Information				Boat to Boat - Waiheke/Whangaroa	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Public Correspondence (Ship-to-Shore full-duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
63	156.175	160.775	HM Coastguard Maritime Safety Information (half-duplex)				Boat to Boat - Manukau	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Coast Guard, Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
64	156.225	160.825	HM Coastguard Maritime Safety Information (half-duplex)	A  Illegal for public use				Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Coast Guard, Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore full-duplex)
65	156.275	160.875	National Coastwatch Institution (NCI) and Independent Coastwatch Stations (http://www.seasafetygroup.org) Working Channel for communication with local mariners for radio checks and local sea conditions. Effective 1 March 2021.		Marine Assistance Working Channel		Boat to Boat - Coromandel	Public Correspondence (Ship-to-Shore full-duplex) Port Operations	Coast Guard, Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
66	156.325	160.925			Marinas - BC Coast  A			Public Correspondence (Ship-to-Shore Duplex) Port Operations	Public Correspondence (Ship-to-Shore Duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
67	156.375	156.375	UK Small Ship Safety Channel			Working Channel, Marine Weather	Maritime Radio Working Channel	A  VTS (Ship-to-ship + Port Operations)	Coast Guard	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
68	156.425	156.425		Non-commercial  A			Maritime Radio Working Channel	A  Port Operations, Border Guard authorities, also some yacht clubs and marinas	Coast Guard	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
69	156.475	156.475	Port Operations	Non-commercial  A		Australian Navy	Maritime Radio Working channel Surf Lifesaving	A  Ship-to-ship Port Operations	Navy	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
70	156.525	156.525	Digital Selective Calling  A							Not used on: Main stem, River, Canal, Lake, Pond.
71	156.575	156.575	Port Operations	Non-commercial  A			Maritime Radio Working Channel	A  VTS (Ship-to-ship + Port Operations) Port Operations	Navy	Port Operations
72	156.625	156.625	Ship-to-ship  A Frequently used by leisure craft	Non-commercial ship-to-ship  A	Ship-to-ship			A  Ship-to-ship Ship-to-air	A  Ship-to-ship, communications with a social (ship)	A  Ship-to-ship, communications with a social (ship) (limited to 1 watt)
73	156.675	156.675	HM Coastguard Safety Broadcasts Backup Small Ship Safety			Ship-to-ship	Marinas - Working	A  Ship-to-ship Ship-to-air (Port Operations)	Port Operations, Navy	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
74	156.725	156.725	British Waterways/Canal and River Trust Channel (Canal and River System) Port Operations			Ship-to-ship	Working - Coast/Ship	A  Port Operations	Port Operations, Navy, Maritime Gendarmerie	Port Operations
75	156.775	156.775	Navigation related communications (limited to 1 watt)					A Restricted Ship-to-ship Port Operations	A Restricted Ship-to-ship Port Operations, (limited to 1 watt)	Port Operations
76	156.825	156.825						A  Restricted Port Operations	A Restricted Ship-to-ship Port Operations, (limited to 1 watt)	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
77	156.875	156.875	Ship-to-ship  A			Ship-to-ship		A  Ship-to-ship	A  Ship-to-ship, communications with a social (ship)	A  Ship-to-ship, communications with a social (ship) (limited to 1 watt)
78	156.925	161.525		Non-commercial  A				Public Correspondence (Ship-to-Shore Duplex) Port Operations	Public Correspondence (Ship-to-Shore Duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
79	156.975	161.575						Public Correspondence (Ship-to-Shore Duplex) Port Operations	Customs Coast Guard, search and rescue, Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
80	157.025	161.625	UK Marina Channel			Repeater Operations	Coastguard Radio - Working Channel	GOFREP on Gulf of Finland Public Correspondence (Ship-to-Shore Duplex) Port Operations	Customs, Coast Guard, search and rescue, Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
81	157.075	161.675		A  U.S. Government Use Only		Repeater Operations	Coastguard Radio - Working Channel	GOFREP (Estonia) on Gulf of Finland Public Correspondence (Ship-to-Shore Duplex) Port Operations	Public Correspondence (Ship-to-Shore Duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
82	157.125	161.725		A  U.S. Government Use Only	Canadian Coast Guard - Working Channel		Coastguard Radio - Working Channel	Public Correspondence (Ship-to-Shore Duplex) Port Operations	Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
83	157.175	161.775		A  U.S. Coast Guard Use Only	Canadian Coast Guard - Working Channel			Public Correspondence (Ship-to-Shore Duplex) Port Operations	Public Correspondence (Ship-to-Shore Duplex) Port Operations	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
84	157.225	161.825	HM Coastguard Maritime Safety Information - Now on 62,63,64				Coastguard Radio - Working Channel	Public Correspondence (Ship-to-Shore Duplex) Port Operations	Public Correspondence (Ship-to-Shore Duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
85	157.275	161.875	UKSAR TWC (half-duplex)		Radio Telephone - full duplex		Coastguard Radio - Working Channel	Public Correspondence (Ship-to-Shore Duplex) Port Operations	Navy	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
86	157.325	161.925	HM Coastguard Maritime Safety Information- Now on 62,63,64				Coastguard Radio - Working Channel	Public Correspondence (Ship-to-Shore Duplex) Port Operations	Navy	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
87	157.375	157.375						Public Correspondence Port Operations	Public Correspondence (Ship-to-Shore Duplex), Independent radio networks, Customs Coast Guard, search and rescue	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
88	157.425	157.425						Commercial, Internship only.	Public Correspondence (Ship-to-Shore Duplex), Independent radio networks	Radiotelephone links between ship stations and land stations of the authorities responsible for the operation of inland waterways (Ship-to-Shore Duplex)
M2/P4	161.425	161.425	(As M2) Yacht clubs, race committees and marinas							(As P4) In France, some yacht clubs, marinas and race committees
87B	161.975	161.975	Automatic Identification System  A  B
88B	162.025	162.025	Automatic Identification System  A  B
L1	155.500	155.500						Leisure activities. (Ship-to-ship) Used in the Nordic countries and Estonia
L2	155.525	155.525						Leisure activities. (Ship-to-ship) Used in the Nordic countries and Estonia
L3	155.650	155.650						Leisure activities. (Ship-to-ship) Used in Finland and Norway
F1	155.625	155.625						Fishing. (Ship-to-ship) Used in the Nordic countries
F2	155.775	155.775						Fishing. (Ship-to-ship) Used in the Nordic countries
F3	155.825	155.825						Fishing, also recreational fishing (Ship-to-ship) Used in the Nordic countries

dBm

Power level	Power	Notes
526 dBm	3.6×1049 W	Black hole collision, the power radiated in gravitational waves following the collision GW150914, estimated at 50 times the power output of all the stars in the observable universe.
420 dBm	1×1039 W	Cygnus A, one of the most powerful radio sources in the sky
296 dBm	3.846×1026 W	Total power output of the Sun
120 dBm	1 GW	Experimental high-power microwave (HPM) generation system, 1GW at 2.32 GHz for 38 ns
105 dBm	32 MW	AN/FPS-85 Phased Array Space Surveillance Radar, claimed by the US Space Force as the most powerful radar in the world.
95.5 dBm	3,600 kW	High-frequency Active Auroral Research Program maximum power output, the most powerful shortwave station in 2012
80 dBm	100 kW	Typical transmission power of FM radio station with 50-kilometre (31 mi) range
62 dBm	1.588 kW = 1,588 W	1,500 W is the maximal legal power output of a US ham radio station.
60 dBm	1 kW = 1,000 W	Typical combined radiated RF power of microwave oven elements
55 dBm	~300 W	Typical single-channel RF output power of a Ku band geostationary satellite
50 dBm	100 W	Typical total thermal radiation emitted by a human body, peak at 31.5 THz (9.5 μm) Typical maximal output RF power from a ham radio HF transceiver
40 dBm	10 W	Typical power-line communication (PLC) transmission power
37 dBm	5 W	Typical maximal output RF power from a handheld ham radio VHF/UHF transceiver
36 dBm	4 W	Typical maximal output power for a citizens band radio station (27 MHz) in many countries
33 dBm	2 W	Maximal output from a UMTS/3G mobile phone (power class 1 mobiles) Maximal output from a GSM850/900 mobile phone
30 dBm	1 W = 1000 mW	DCS or GSM 1,800/1,900 MHz mobile phone. EIRP IEEE 802.11a (20 MHz-wide channels) in either 5 GHz subband 2 (5,470–5,725 MHz) provided that transmitters are also IEEE 802.11h-compliant, or U-NII-3 (5,725–5,825 MHz). The former is EU only, the latter is US only. Also, maximal power allowed by the FCC for American amateur radio licensees to fly radio-controlled aircraft or operate RC models of any other type on the amateur radio bands in the US.
29 dBm	794 mW
28 dBm	631 mW
27 dBm	500 mW	Typical cellular phone transmission power Maximal output from a UMTS/3G mobile phone (power class 2 mobiles)
26 dBm	400 mW
25 dBm	316 mW
24 dBm	251 mW	Maximal output from a UMTS/3G mobile phone (power class 3 mobiles) 1,880–1,900 MHz DECT (250 mW per 1,728 kHz channel). EIRP for wireless LAN IEEE 802.11a (20 MHz-wide channels) in either the 5 GHz subband 1 (5,180–5,320 MHz) or U-NII-2 and -W ranges (5,250–5,350 MHz & 5,470–5,725 MHz, respectively). The former is EU only, the latter is US only.
23 dBm	200 mW	EIRP for IEEE 802.11n wireless LAN 40 MHz-wide (5 mW/MHz) channels in 5 GHz subband 4 (5,735–5,835 MHz, US only) or 5 GHz subband 2 (5,470–5,725 MHz, EU only). Also applies to 20 MHz-wide (10 mW/MHz) IEEE 802.11a wireless LAN in 5 GHz subband 1 (5,180–5,320 MHz) if also IEEE 802.11h-compliant (otherwise only 3 mW/MHz → 60 mW when unable to dynamically adjust transmission power, and only 1.5 mW/MHz → 30 mW when a transmitter also cannot dynamically select frequency).
22 dBm	158 mW
21 dBm	125 mW	Maximal output from a UMTS/3G mobile phone (power class 4 mobiles)
20 dBm	100 mW	EIRP for IEEE 802.11b/g wireless LAN 20 MHz-wide channels in the 2.4 GHz Wi-Fi/ISM band (5 mW/MHz). Bluetooth Class 1 radio. Maximal output power from unlicensed AM transmitter per US FCC rules 15.219
19 dBm	79 mW
18 dBm	63 mW
17 dBm	50 mW
15 dBm	32 mW	Typical wireless LAN transmission power in laptops
10 dBm	10 mW
7 dBm	5.0 mW	Common power level required to test the automatic gain control circuitry in an AM receiver
6 dBm	4.0 mW
5 dBm	3.2 mW
4 dBm	2.5 mW	Bluetooth Class 2 radio, 10 m range
3 dBm	2.0 mW
2 dBm	1.6 mW
1 dBm	1.3 mW
0 dBm	1.0 mW = 1000 μW	Bluetooth standard (Class 3) radio, 1 m range
−1 dBm	794 μW
−3 dBm	501 μW
−5 dBm	316 μW
−10 dBm	100 μW	Maximal received signal power of wireless network (802.11 variants)
−13 dBm	50.12 μW	Dial tone for the precise tone plan found on public switched telephone networks in North America
−20 dBm	10 μW
−30 dBm	1.0 μW = 1000 nW
−40 dBm	100 nW
−50 dBm	10 nW
−60 dBm	1.0 nW = 1000 pW	The Earth receives one nanowatt per square metre from a magnitude +3.5 star
−70 dBm	100 pW
−73 dBm	50.12 pW	"S9" signal strength, a strong signal, on the S meter of a typical ham or shortwave radio receiver
−80 dBm	10 pW
−100 dBm	0.1 pW	Minimal received signal power of wireless network (802.11 variants)
−111 dBm	0.008 pW = 8 fW	Thermal noise floor for commercial GPS single-channel signal bandwidth (2 MHz)
−127.5 dBm	0.178 fW = 178 aW	Typical received signal power from a GPS satellite
−174 dBm	0.004 aW = 4 zW	Thermal noise floor for 1 Hz bandwidth at room temperature (20 °C)
−192.5 dBm	0.056 zW = 56 yW	Thermal noise floor for 1 Hz bandwidth in outer space (4 kelvins)
−∞ dBm	0 W	Zero power is not well-expressed in dBm (value is negative infinity)