28-03-2017, 09:29 PM
There seems to be a perception in some circles that UHF is somehow superior to VHF for TV and that it was/is something to aspire to. - not so, in fact the reverse is the case as any study of coverage versus transmitter power (& electrical power consumption) will reveal. There also appears to be an idea that use of VHF or UHF is, in some way, related to line standard - it is not.
Broadcasters only moved to UHF for one of two reasons:
1. When they ran out of VHF spectrum and needed to add more channels (most countries)
or
2. Because VHF spectrum was already occupied by legacy transmissions (Britain &France)(405 line in the British case and .....819 line in the French case)
So the natural progression was to start with Band 1 followed by Band 3 and then UHF only when Bands 1 and 3 were full.
The use of Band 1 was later discontinued because of Co-channel interference and only 3 channels available (assuming 7 or 8 MHz channels. This situation pertained until analogue switch-off although most countries have specified both Band 3 and UHF for DTT (eg Australia) and most DTT boxes can handle Band 3 natively (some local 'nobbled' versions have been restricted to UHF but these are in a minority)
Broadcasters only moved to UHF for one of two reasons:
1. When they ran out of VHF spectrum and needed to add more channels (most countries)
or
2. Because VHF spectrum was already occupied by legacy transmissions (Britain &France)(405 line in the British case and .....819 line in the French case)
So the natural progression was to start with Band 1 followed by Band 3 and then UHF only when Bands 1 and 3 were full.
The use of Band 1 was later discontinued because of Co-channel interference and only 3 channels available (assuming 7 or 8 MHz channels. This situation pertained until analogue switch-off although most countries have specified both Band 3 and UHF for DTT (eg Australia) and most DTT boxes can handle Band 3 natively (some local 'nobbled' versions have been restricted to UHF but these are in a minority)
