VHF broadcasting
VHF radio ( English : FM radio ) stands for radio on band II of the ultra-short wave .
Technical details
VHF radio in the CCIR band is broadcast worldwide in VHF band II between 87.5 MHz and 108 MHz, with some countries only using partial ranges. The OIRT band from 65.8 MHz to 74 MHz is only used in Japan and some countries of the former Eastern Bloc and in the future also in Brazil . When modulation is frequency modulation (FM) is used. This enables sound signals to be transmitted less susceptible to interference, as it is less sensitive to atmospheric interference compared to the amplitude modulation (AM) used in the long , medium and short wave ranges. Band II still has a bandwidth of 20.5 MHz, which is about twenty times as much as the 1.08 MHz of the entire medium wave range. This area was originally divided into a channel grid of 300 kHz each. This channel grid was only used in the early days and has given way to a flexible allocation of transmission frequencies in a 100 kHz grid; in cable networks and in Italy, a 50 kHz grid is used. The respective nominal band limits are mostly left out; For example, in Germany the frequencies 87.5 and 108.0 MHz may only be used as carrier frequencies in cable networks, because otherwise Articles 4.4 and 4.5 of the World Radio Treaty would be violated.
By cleverly assigning frequencies, one tries to keep a minimum distance of 300 kHz between relevant transmitters in a region. Nevertheless, the individual radio stations have a much larger bandwidth available compared to radio in the AM bands , which allows high-quality sound quality ( high fidelity ) as well as two-channel stereo transmission to be achieved. To improve the signal-to-noise ratio, VHF broadcasting also raises the treble when transmitting and then lowers it again on the receiver side, which reduces the noise. This technique is known as emphasis . The time constants of this pre-emphasis are different in the USA (with 75 µs) and in the rest of the world (with 50 µs).
The pilot tone method is used for stereo transmission .
Due to the higher bandwidth, the channel grid allows the transmission of additional services such as the Radio Data System (RDS) or the ARI identification of traffic announcements, which was used until 2012 .
Between 1974 and 1998, 87.340 MHz and 87.365 MHz was the so-called in Germany on the frequencies euros signal broadcast, a wireless pager.
FM broadcasting in China
In China, the FM band already starts at 87 MHz.
VHF broadcasting in French overseas territories
In contrast to the French heartland, in some French overseas territories ( French Guiana , Guadeloupe , Martinique , Saint-Barthélemy , Saint-Martin , Saint-Pierre and Miquelon ) the VHF band only starts at 88 MHz.
VHF broadcasting in Great Britain and Ireland
The UK and Ireland use the 88.0 MHz to 107.9 MHz range.
VHF broadcasting in the countries of Eastern Europe
In the former socialist countries of Eastern Europe (with the exception of the GDR ), the Soviet Union and Mongolia , the frequency range from 65.9 to 73.1 MHz, the so-called OIRT band , was defined for VHF broadcasting. Only after the fall of 1989/90 did some countries gradually switch to Volume II, which was used in the Western European countries.
Today, both frequency ranges are often still active - in Russia, for example, a distinction is made (in everyday speech) between FM (87.5 MHz to 108.0 MHz) and VHF (65.9 to 73.1 MHz).
In contrast to the DA-CH region , the 87.5 MHz carrier frequency can be used regularly in Russia. For example, in Moscow Business FM broadcasts on this frequency. In addition, Radio 1 broadcasts on this frequency in Częstochowa Polskie, Poland .
The OIRT band is guaranteed by footnotes 5.175 and 5.177 to the World Radio Agreement .
VHF broadcasting in Japan
In Japan , the frequency range 76 to 90 MHz is used for VHF broadcasting, the upper limit of which is to be raised to 95 MHz.
As in the DA-CH region, a 100 kHz channel grid is used in Japan.
As in the DA-CH region, the respective band limits in Japan (there: 76.0 and 95.0 MHz, as well as 90.0 MHz for the time being) cannot be used as carrier frequencies, while the carrier frequency 87.5 MHz in Japan is used by NHK is used.
The Japanese VHF band is guaranteed by footnote 5.183 to the World Radio Agreement.
VHF broadcasting in Norway
In Norway , analogue VHF broadcasting has only been used for local radio since December 13, 2017.
VHF broadcasting in South Korea
In South Korea , the frequency range 88 to 108 MHz is used for VHF broadcasting.
VHF broadcasting in Southeast Asia
In Cambodia , Laos and Thailand the frequency range 87.5 to 108 MHz is used for VHF broadcasting with a (not consistently adhered to) channel spacing of 250 kHz; unlike in the DA-CH region, the band limits can also be used as carrier frequencies.
VHF broadcasting in the United States
In the USA, the usable frequency range is set at 87.9 to 107.9 MHz, an uneven 200 kHz grid is used (87.9 MHz, 88.1 MHz, 88.3 MHz… 107.9 MHz).
The altitude increase when sending is 75 µs in all of North America and several other countries (including Colombia, Korea and the Vatican, but in some countries this is not even uniform) , in contrast to the 50 µs in most other countries. This results in differences in the reproduction in the high frequency range .
history
In 1925 the world's first VHF transmission took place between Jena and Kahla by Professor Abraham Esau .
After the Second World War , the frequencies for European broadcasters were reassigned at the International Broadcasting Conference in Atlantic City . According to the Copenhagen Wave Plan , the loser countries were allocated very few, unfavorable frequencies in the medium wave range . For this reason, the planning of ultra-short wave transmitters was promoted in these countries in particular . The first European VHF transmitter was put into operation on February 28, 1949 in Munich-Freimann by Bayerischer Rundfunk (90.1 MHz).
| Bavarian radio | 27 |
| Hessian radio | 7th |
| Northwest German Broadcasting | 29 |
| Radio Bremen | 2 |
| Süddeutscher Rundfunk | 12 |
| Südwestfunk | 27 |
| Sender Free Berlin | 2 |
| All in all | 106 |
The station Free Berlin broadcast the first stereo broadcasts on VHF in Germany on the occasion of the radio exhibition in 1963. From 1968 onwards, every state broadcaster broadcast at least one VHF program in stereo.
Until 1964, only frequencies from 87.5 MHz to 100 MHz were used for VHF broadcasting in Germany. Then the frequency range was expanded, initially to 104.5 and from 1968 to 108 MHz. The receiver manufacturers followed with a delay, which is why in the 1970s devices with a VHF scale up to 104.5 were offered alongside those up to 108 MHz. The frequencies above 100 MHz were only coordinated on a large scale after the introduction of private broadcasters (from around the mid-1980s). That is why most of the private program providers can be found here.
In Germany, FM transmitters are currently (2014) operated by the nine state broadcasting corporations, Deutschlandradio (with the two FM programs Deutschlandfunk and Deutschlandfunk Kultur ), by soldiers' broadcasters such as AFN and BFBS and by private program providers.
Since 2006, VHF transmitters with a short range of a few meters (up to 50 nW ERP permitted radiated power) have been operated in Germany and Switzerland , e.g. B. for the transmission of signals from an MP3 player to the car radio , allowed. These devices are commercially available as FM modulators, FM transmitters ( mini transmitters ), etc.
The future of VHF broadcasting
Digital broadcasting in the form of DAB (Digital Audio Broadcasting) was seen as the successor to analogue VHF broadcasting . It was planned to end analogue broadcasting of broadcasting programs in the EU in 2012 after digital broadcasting had spread. This goal was clearly missed, see analog shutdown . In Germany and Austria, the conventional DAB standard could not establish itself, in Austria it was even discontinued. In the meantime, the incompatible successor DAB + was introduced, first in Germany, and later also in Austria. Although the introduction of DAB was more successful in Switzerland, it has now been replaced by DAB + there too. In the rest of Europe the situation is confusing, in some places operations have been stopped again, in other countries it seems to be partially successful. See also Digital Audio Broadcasting in Europe
Situation in Germany
In 2000, the federal government stated "that [...] VHF radio should be replaced by digital audio broadcasting (DAB)." The prerequisite for this would be that DAB prevail on the market. The joint efforts of all those involved should ensure that the vast majority of listeners will use digital radio in 2010 and that analogue radio broadcasting could end in 2010. As early as 2005, the Digital Broadcasting Initiative stated in a report that DAB had not yet been able to establish itself sufficiently and that analogue VHF radio would therefore remain the most important distribution channel in the long term. Regardless of this, the goal of replacing analogue VHF radio transmission with a digital system is still being adhered to and Volume II is to be permanently available for broadcasting.
In the meantime there were considerations to digitize the VHF range with the narrowband systems DRM + or HD radio . This technology would have made it possible to switch individual FM frequencies from analog to digital use. After the introduction of DAB failed, a further attempt was made in 2011 with the introduction of the successor DAB +. Since the standards are incompatible, new devices have to be purchased. Nevertheless, there are some successes in dissemination.
Before the analog switch-off, radio in the cable networks was also transmitted via VHF and mostly local transmitters were fed into the cable networks on different frequencies. For example, SFB 1 in Berlin (terrestrial FM frequency 88.8 MHz) was transmitted by Kabel Deutschland on the FM frequency 94.85 MHz because this frequency was not used terrestrially and was therefore free for use in cable television. In some cases, the broadcasters recommended connecting the same receivers to the cable instead of the cable to a terrestrial antenna to avoid having to buy a new digital receiver. With Vodafone Kabel Deutschland, the first large operator of a German cable television network ended VHF transmission in November 2018. Unitymedia, on the other hand, is still sticking to feeding VHF radio into the cable network. According to the initiative "Digitales Kabel" (representatives of several cable network operators), the digital successor standard DVB-C is for VHF in the cable that is switched off , although DAB or DAB + are also available as successors for up to 200 radio programs in the cable network and are being tested u. a. has already been used by Bayerischer Rundfunk. In Saxony, in unfavorable topographical locations, where there are partial restrictions on terrestrial VHF reception, VHF can be broadcast in the cable beyond the shutdown date decided by the government.
Situation in Austria
Situation in Switzerland
Situation in Italy
Individual evidence
- ↑ http://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.43.48.en.101.pdf Radio Regulations, edition of 2016: Volume 1: Articles - 1.43.48.en.101.pdf
- ↑ This pre-emphasis, known as preemphasis, is counterproductive with the introduction of stereophony and the changes in today's music, as the multiplex process for stereo signals produces a rather white noise (instead of triangular noise) and the high frequency component of "modern" music, which has increased since the 1980s, causes level problems .
- ↑ https://www.anfr.fr/fileadmin/mediatheque/documents/tnrbf/TNRBF_Ed2013_Mod8_-_Version_du_19_f%C3%A9vrier_2016.pdf French frequency usage plan
- ↑ http://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.43.48.en.101.pdf Radio Regulations, edition of 2016: Volume 1: Articles - 1.43.48.en.101.pdf
- ↑ The FM story. Retrieved July 13, 2017 .
- ↑ http://www.fmlist.org/ul_frameset.php
- ↑ http://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.43.48.en.101.pdf Radio Regulations, edition of 2016: Volume 1: Articles - 1.43.48.en.101.pdf
- ↑ http://www.fmlist.org/ul_frameset.php
- ↑ Vfg 7/2006 general allocation of frequencies in the frequency ranges 87.5-108 MHz, 863-865 MHz and 1795-1800 MHz for wireless audio radio applications. Federal Network Agency , accessed on February 14, 2017 .
- ↑ Federal Network Agency permits private radio with 50 nanowatts on heise online from March 8, 2006
- ↑ Berliner Kabelnetz in Kabel Deutschland's Helpdesk from 1991, accessed on March 18, 2019
- ↑ Cable networks converted to digital. br.de, January 24, 2019
- ↑ Switching off analog cable programs: All information. NDR, January 22, 2019
- ↑ Your questions about the digital switchover in cable.
- ↑ Michael Fuhr: Vodafone switches off FM radio in the cable. Telariff, October 16, 2017
- ↑ Michael Fuhr: DAB + digital radio comes into the cable in Germany. Telariff, February 4, 2018
- ↑ Cable TV can only be received digitally from Monday. Free press, January 4, 2019