colly0410 wrote:Anyone think of any other advantages/disadvantages of band 1?
Synchrodyne wrote:... The very low end of Band I seems to suffer from problems that can cause significant frequency response lumpiness, particularly when relatively simple aerials are used. I saw an extreme case of this – really serious suckout at the sound carrier – with channel Aus2 in Sydney. But I have also seen it with channel NZ1 in Wellington and to a lesser extent with NZ2 in Auckland. In Dallas I had a multi-element array in the roofspace, but channel A2 was never as “clean” as channels A4 and A5, even though there was no shortage of signal. (The transmitters were more-or-less co-sited on an antenna farm over at Cedar Hill.) ...
colly0410 wrote:Wouldn't it have been fun (OK probably not) if the UK had adopted 525/50 as it replacement for 405? No one would ever export to us.
Synchrodyne wrote:Also, somewhere along the way, the NTSC nominal vision bandwidth moved up to 4.2 MHz from the 4 MHz noted in the original NTSC I documents. This seems to have happened before NTSC II determined the colour system parameters. But on the other hand, the tabulation in Wireless World 1952 August still shows 4 MHz. By deduction, it looks as if System N started with 4 MHz and moved up to 4.2 MHz to stay in step with NTSC.
Synchrodyne wrote:Some of the “fine detail” remains obscure, though. For example, when was the NTSC TV standard, as developed by NTSC I in 1941, adjusted in terms of its sound carrier characteristics. Originally it was specified with ±75 kHz deviation and 100 µs pre-emphasis, the same as then used for FM broadcasting. Then it was later changed to ±25 kHz deviation and 75 µs pre-emphasis. My working hypothesis is that the two parameter changes were concurrent, and became effective with the 1946 channel assignments, but I have no supporting data. In the case of FM broadcasting, there is empirical evidence that 100 µs pre-emphasis was retained for the 42 to 50 MHz band at least up until 1945, and perhaps until the end of transmissions in this band. Again the (unsupported) working hypothesis is that 75 µs was prescribed for the 88 to 108 MHz band from the start.
Katie Bush wrote:On the other hand.....
Like anything else, if you're immersed in your viewing, your eyes/brain make up for any shortfall - you're watching the show, not the "delivery system".. Many's the time I never even registered the fact I was watching in black & white!
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