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).
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.
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|
|CELLULAR SERVICE except aeronautical mobile service||civil||Commercial radio, inland water radio, marine radio service|
|MOBILE MARINE SERVICE (emergency and call)||civil, mil|
|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
- ↑ 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.