> On May 19, 2015, at 13:47, tony duell <a...@p850ug1.demon.co.uk> wrote: > > Most, if not, all home computers sold to connect to TVs in the UK were set to > use our UHF channel 36.
> VHF channels were not used for broadcast 625 line TV in the UK, and most TVs > could not tune to them. So you > will not find a UK home computer using VHF RF output. Thanks! Those are the sorts of details that are hard to know with only my US computer/TV experience. That NTSC ZX-81 is the first I have heard of a computer with UHF TV output in the U.S., but it makes sense to minimize the hardware changes for the U.S. market. Might have used the same modulator, possibly with a coil adjusted a bit differently in the factory. Native US gear was all VHF in my experience. Usually switchable between channels 3 and 4 to avoid whichever channel had a strong local station, and also commonly using an Astec modulator. I still have a nagging feeling that I might have seen something with channel 2 output, but can't remember where I think I saw it.
