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Re: TVI (was snow on telly results)
> It was intended as a serious question on a serious issue.
> I hope no-one took offense to it. In the absence of any info from US
> coilers (or any other countries), I am still wondering why we seem to get
so
> many TVI problems from coiling here in the UK, that US coilers dont seem
to
> suffer.
About 20 years ago (maybe even 30 years), the FCC promulgated a whole
batch of new rules regulating electromagnetic susceptibility of electronic
devices, in large part because the increasing prevalence of high gain,
small transistorized devices was making it more of a problem. Now, after
all these years, very little of the non-immune equipment is still around
(largely due to planned obsolescence in our consumer oriented culture..
gotta have the latest model TV, don't you know...). As I recall, the last
big fiascos were cordless phones operating at 1.7 MHz and PC's that
radiated lots of EMI (before the FCC cracked down on Part 15).
Perhaps there is a higher prevalence of non-immune equipment in the UK?
Newer stuff has to comply with the CE directives which place a big emphasis
on EMC and EMI issues, but there is still a bunch of older stuff out there.
Perhaps residential wiring practices are different. Here in the US, one
side of the power line is grounded at the service entrance. Is the same
true in the UK, or are both sides floated off ground. When I lived in
Spain, I was amazed at the variety of wiring practices (as well as the huge
rats nest of wires in the air shaft of my building). There is an EMI
nightmare waiting for the unwary Spanish coiler...
Is the housing density higher? My wife's uncles and aunts live in
moderately suburban areas of the UK (Surrey, Wiltshire), but I notice that
in at least one case, while the overall density is lower, it is more
"clumped", and the houses are much closer together.
What about EMI problems with ham radio? Surely someone is running a kW on
HF and finding out?
I would think that the TV itself should be roughly the same between US and
UK. They all use a 45 MHz IF, pretty much, even if the channels are at
different frequencies. I just threw away an old dual standard B&W TV
(tubes) a few years back.. I should have saved it for some empirical
susceptibility tests.
>
> >Best regards everyone, Martin Dale, TCBON (also G6ABU!)
>
>