Re: TV standards (was Did Commodore cheat...)

Den Thu, 17 Jan 2019 15:51:50 -0500 skrev "Mike Stein"
<mhs.stein@gmail.com>:
> > On 2019-01-15, at 03:10, Mia Magnusson <mia@plea.se> wrote:
> > 
> > Den Sun, 13 Jan 2019 13:48:31 +0000 skrev smf <smf@null.net>:
> >> My 1979 TV didn't have a composite input, you'd need to remember to
> >> take a VHF adapter (I don't recall ever seeing a DVD player with
> >> one built in).
> 
> I saw UHF only.

Mee too :)
 
> >> I'm asking as a VHF modulator were afaik only used in the NTSC
> >> part of the world,
> 
> > If you talk like external modulators than you may be right (I don't
> > recall seeing those either). In general though we used to use VHF
> > for broadcast in non-NTSC part of the world too. Obviously there
> > wasn't much room in this band so only 12 channels were available
> > for broadcast use on VHF. UHF was added later on and for a
> > relatively long time TV sets had both bands. I /think/ VHF channels
> > were still in use in this millenium.

Yes, they sure were, but since for example the UK never had 625 lines
on VHF, and since there were some agreements between the authorities in
a bunch of countries, consumer RF modulators in the 625 line part of
the world were almost always made for channels about 30-40, with 36
being the usual default. Channel 36 were/is afaik reserved for RF
modulators and not supposed to be used for any broadcast channels,
making it a bit easier for consumers to set up their equipment. Of
course they had to change channels for at least one modulator as soon
as they had more than one modulator. (Side track / anecdote: Back in
the late 80's and early 90's, the premium movie channel called Filmnet,
now Canal Digital, used some analogue encoding of the picture on
satellite broadcast with their own proprietary decoder. The decoder
were set up with channel 40 on it's RF modulator, which collided with
one of the broadcast TV channels in the Stockholm area, the largest
population center in Sweden :) ).

Commercial grade RF modulators are a different thing. Over the air
broadcast TV stations of course used high quality RF modulators. Cable
networks also used RF modulators in the VHF band.

At least in Sweden analogue transmissions were still used in the VHF
band the first years of this millenium. The digital transmissions seems
to only be done on UHF though.

An exception seems to be cable TV networks where analogue
(re)transmissions on VHF with some of the free channels are still
carried out.

> ---
> "*Used to* use" ? "*Were* still in use" ? What do you use now?
> 
> Here in North America VHF channels are definitely still in use in
> this millenium, although with a few exceptions we switched from
> analog to digital ten years ago; according to Wikipedia Europe also
> still uses VHF, albeit on slightly different frequencies.
> 
> Am I missing something?
> 
> FWIW, over here RF modulators, cable and ATSC converters etc. with
> analog RF out almost always use channel 3 or 4, with a few UHF
> exceptions.

Yeah, it seems like the (de-facto?) standard is VHF channel 3 or 4 in
the NTSC/525 line world, and UHF around channel 36 in the PAL/625 line
world.

Nowdays afaik it's hard to find equipment with analogue RF modulators
for sale, except a pure RF modulator in a separate box specifically
aimed at for example vintage TV users and similar.  



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