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| | Ultra high frequency - Open Encyclopedia (Site not responding. Last check: 2007-11-07) |
 | | However, with the emergence of additional broadcast television networks (Fox, UPN, WB, and Pax), the concentration of media ownership, and the proliferation of cable television, digital television, and DSS in the 1990s, the distinction between UHF and VHF stations has virtually disappeared in the United States. |
 | | In Britain, UHF television began with the launch of BBC2 in 1964, using a 625-line system (which had higher resolution, and therefore required greater bandwidth, than the existing 405-line system). |
 | | BBC1 and ITV soon added their own 625-line services on UHF (British channels 21 to 69), and PAL colour was introduced on UHF only in 1967–1969. |
| open-encyclopedia.com /UHF (463 words) |
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