VHF volume I
The VHF band I (short: Band I ) is the frequency range in the VHF range between 47 and 68 MHz. This area is occupied by TV channels 2, 3 and 4, which are used in terrestrial television and cable television . In cable networks, this frequency range is also used for the return channels (5 to 65 MHz) for Internet and telephony, depending on the configuration status .
In the Implementing Regulations for the Radio Service of the International Telecommunication Union , Volume I is assigned to the broadcasting service alongside other radio services, but according to the frequency usage plans of Germany and Austria, this band is no longer used for television broadcasting.
Due to the high transmission power and long range, it was possible to cover large areas with just a few transmitters, but this frequency range is susceptible to overreaches of up to 2000 km.
In Germany, last (until November 2008) only the Ochsenkopf transmitter (channel 4) broadcast in this frequency range. The Band I transmitters Biedenkopf (channel 2), Kreuzberg (channel 3), Grünten (channel 2), Raichberg (channel 4), Flensburg (channel 4) and Göttelborner Höhe (channel 2) were implemented in 2006 and 2007 as part of the conversion switched off on DVB-T .
The so-called ox - head antenna for channel 4 was widespread in the GDR for ARD reception from the transmitter location of the same name and, colloquially, the antenna for western television . Since West Germany and East Germany used the same CCIR channel grid, reception was possible.
Replacement channels in UHF band V ( decimeter wave ) were provided for all transmitters that used VHF band I. However, since these have a significantly shorter range, only a few of the replacement channels were actually used (e.g. channel 55 on the Steinkimmen transmitter or channel 53 on the Calau telecommunications tower ). Numerous substitute channels were used for other purposes, for example channel 60 in Würzburg, originally intended for the Ochsenkopf transmitter, was used for RTL Television .
Analog television channels and frequencies
Overview of the analog TV channels in VHF band I according to the CCIR standard (frequency information in MHz):
| channel | Channel boundaries | Image carrier | Sound carrier |
|---|---|---|---|
| 1 | 41… 47 | - | - |
| 2 | 47… 54 | 48.25 | 53.75 |
| 2A | 48.5 ... 55.5 | 49.75 | 55.25 |
| 3 | 54… 61 | 55.25 | 60.75 |
| 4th | 61… 68 | 62.25 | 67.75 |
Channel 1 was theoretically defined as a channel, but was practically not used. The shifted channel 2A existed outside the usual grid; it was used in Austria by ORF at the Jauerling station (near St. Pölten ) until the station switched to DVB-T. The frequency offset of channel 2A avoided mutual interference with a frequency-like TV transmitter according to the OIRT standard in Hungary. Channel 2A is 1.5 MHz above the frequency of channel 2.
See also
- Frequency band
- VHF band II (VHF radio)
- VHF band III
Web links
Individual evidence
- ↑ Federal Network Agency, Frequency Usage Plan as of April 2008: “New planning is not possible in this frequency range. Volume I will be closed to broadcasting services in the medium term, at the latest when the conversion from analogue to digital television broadcasting is complete. "
- ↑ Federal Law Gazette for the Republic of Austria , Part II. Issued on December 27, 2006, No. 525: “Volume I; no reallocations for analog television. "