Ultra-short wave

Radio technicians test the VHF transceiver in a Hawker Hurricane Mark I of the 601st Squadron RAF, in Exeter, Devon (1940)

As ultra-short waves ( USW ) is referred to electromagnetic waves in a frequency range of 30 MHz to 300 MHz, corresponding to wavelengths between ten meters and one meter. They are thus between the short waves (which are longer than ultra-short waves) and the decimeter waves (which are shorter).

term

In the English- speaking world, the term VHF (very high frequency) is used for ultra-short waves .

For radios, FM (for frequency modulation ) is often used as a synonym for VHF , since analogue radio broadcasts on VHF are only frequency-modulated (in contrast to amplitude modulation / AM ) and, conversely, frequency-modulated radio broadcasts are only broadcast on VHF.

In common parlance, the term VHF is often used to a limited extent for VHF broadcasting in the range 87.5 to 108 MHz of VHF band II. The ultra-short waves also include the frequencies of radio bands I and III used for television stations, as well as the lower and upper special channels of cable television , especially television channels 5 (A) -12 (D) that have been rededicated for digital radio .

The hyperband (extended special channel range) and the radio bands IV and V, on the other hand, belong to the decimeter waves .

Furthermore, the term VHF is also used in the field of speech radio. These are mainly the 4 m band (i.e. the frequencies below VHF broadcasting), the areas of aviation radio with frequencies above 108 MHz and the 2 m band in the range from 140 to 174 MHz, where Many different professional radio services as well as an amateur radio band are located.

Range

The range of the ultrashort waves is limited by the horizon of electromagnetic wave propagation . This does not correspond to the optical horizon for visible light, since the refractive index of the earth's atmosphere for the VHF frequency range decreases with height above ground. The curvature of the earth therefore appears flatter for the ultra-short waves than for visible light. The so-called radio horizon is thus further away than the optical horizon. In contrast to long , medium and shortwave broadcasting , ultrashort radio waves are not reflected by the ionosphere , apart from the overreaches that occur sporadically in summer ( Sporadic-E ) , so that their terrestrial range is significantly smaller. In certain inversion weather conditions, however, overreaching can occur. Depending on the transmitter and receiver location, the transmission power and the receiving equipment, the range of a VHF transmitter is between a few 10 and around 200 km. An FM transmitter network therefore consists of a large number of transmitters that are set up at short intervals, usually on hills. In mountainous areas one often uses gap-fillers one.

Situation in Germany

The first VHF transmitter in Germany started on February 28, 1949 at 4:30 p.m. on the premises of Bayerischer Rundfunk in Munich-Freimann . The current frequency plan was adopted in March 2019.

Using the FM frequency spectrum

Assignment to radio services
Frequency range	Federal Republic of Germany	use	comment
30.005-30.1 MHz	SPACE REMOTE RADIO SERVICE , MOBILE RADIO SERVICE , SPACE RESEARCH RADIO SERVICE , Fixed radio service	civil, mil
30.01-34.35 MHz	MOBILE SERVICE , Fixed radio service	civil, mil	wireless microphones
34.35-36.55 MHz	MOBILE SERVICE , Fixed radio service	civil	Model remote control, wireless microphones, commercial radio, radio applications BOS
36.55-37.75 MHz	MOBILE SERVICE , Fixed radio service	civil, mil	wireless microphones, radio control systems, remote control systems
37.75-38.25 MHz	MOBILE RADIO SERVICE , Fixed Radio Service , Radio Astronomy	civil, mil	wireless microphones, radio control systems, remote control systems
38.25-38.45 MHz	MOBILE SERVICE , Fixed radio service	civil, mil
38.45-39.85 MHz	MOBILE SERVICE , Fixed radio service	civil	Radio applications BOS
39.85-41 MHz	MOBILE SERVICE , Fixed radio service	civil, mil	Paging systems, telecontrol systems, model remote control, ISM applications
41-47 MHz	MOBILE SERVICE , Fixed radio service	military
47-68 MHz	BROADCASTING SERVICE , MOBILE LANDING SERVICE , amateur radio service	civil, mil	TV broadcasting in defined geographical areas ( Volume I )
68-70 MHz	MOBILE LAND RADIO SERVICE	civil	Commercial radio, radio applications for railways
70-74.2 MHz	FIXED RADIO SERVICE , MOBILE RADIO SERVICE except mobile aeronautical radio service	military
74.2-74.8 MHz	MOBILE LAND RADIO SERVICE	civil	Radio applications BOS
74.8-75.2 MHz	FLIGHT NAVIGATION RADIO SERVICE	civil, mil	Marker beacon of air traffic control
75.2-78.7 MHz	MOBILE LAND RADIO SERVICE	civil	Railway radio applications, commercial radio, BOS radio applications
78.7-84 MHz	MOBILE RADIO SERVICE except mobile aeronautical radio service , fixed radio service	military
84-87.5 MHz	MOBILE LAND RADIO SERVICE	civil	BOS radio applications, Eurosignal radio call service
87.5-108 MHz	BROADCASTING	civil	Radio via VHF radio (also known as FM )
108-117.957 MHz	FLIGHT NAVIGATION RADIO SERVICE	civil, mil	VHF rotating radio beacon (VOR) and landing course transmitter (ILS) of air traffic control
117.975-137 MHz	MOBILE AIRCRAFT SERVICE (R)	civil, mil	Radiotelephony for air traffic control purposes
137-138 MHz	SPACE RADIO SERVICE , WEATHER SERVICE VIA SATELLITES , SPACE RESEARCH RADIO SERVICE , cellular service via satellite	civil	Weather satellites
138-144 MHz	MOBILE AIRCRAFT SERVICE (OR) , MOBILE LANDING SERVICE , space research radio service	military	Aeronautical radio
144-146 MHz	AMATEUR RADIO SERVICE , AMATEUR RADIO SERVICE VIA SATELLITE	civil
146-148 MHz	MOBILE LAND RADIO SERVICE	civil	Commercial radio, radio applications for railways
148-149.9 MHz	CELLULAR SERVICE , cellular service via satellite	civil	Commercial radio
149.9-150.05 MHz	NAVIGATION RADIO SERVICE VIA SATELLITE , MOBILE LAND RADIO SERVICE VIA SATELLITE	civil	Zigada, transit
150.05– 156.7625 MHz	CELLULAR SERVICE except aeronautical mobile service	civil	Commercial radio, inland water radio, marine radio service
156.7625– 156.8375 MHz	MOBILE MARINE SERVICE (emergency and call)	civil, mil
156.8375– 174 MHz	CELLULAR SERVICE except aeronautical mobile service	civil	Commercial radio, ERMES radio paging service, marine radio service, BOS radio , railway radio applications, remote control radio systems
174-223 MHz	BROADCASTING	civil	DAB , reportage radio
223-230 MHz	RUNDFUNKDIENST , mobile land radio service	civil, mil	DAB
230-235 MHz	MOBILE RADIO SERVICE , Fixed radio service ,	military	Aviation radio, directional radio
235-272 MHz	MOBILE RADIO SERVICE , Fixed radio service ,	military	Aviation radio, directional radio
272-273 MHz	MOBILE RADIO SERVICE , Space Telecontrol Service , Fixed Radio Service	military	Aviation radio, directional radio
273-312 MHz	MOBILE RADIO SERVICE , Fixed radio service ,	military	Aviation radio, directional radio

Note on notation:

in CAPITALS: primary radio service
in normal type: secondary radio service

Individual evidence

↑ Recommendation ITU-R P.453-9: The radio refractive index: its formula and refractivity data , ITU 2003.
↑ The future is digital . In: New Germany . Neues Deutschland Druckerei und Verlag GmbH, February 28, 2019, ISSN 0323-3375 , p. 19 .
↑ Frequency plan on the website of the Federal Network Agency, accessed on March 24, 2019.

[P.453-1] Recommendation ITU-R P.453-9: The radio refractive index: its formula and refractivity data , ITU 2003.

[2] The future is digital . In: New Germany . Neues Deutschland Druckerei und Verlag GmbH, February 28, 2019, ISSN 0323-3375 , p. 19 .

[3] Frequency plan on the website of the Federal Network Agency, accessed on March 24, 2019.