-ex- wrote:
Andrew VK3BFA wrote:


-ex- wrote:


We also have a FM broadcast channel on the same tower as the VHF
transmitters - it QRM's TV ch 10 depending on how good the tuner front
end is. - Funnily enough, (well, it isnt really, more obvious) the
older style rotary UHF tuners with ganged RF and LO tuning dont seem to
have any trouble, only the varactor tuned ones. But then, they are the
sweepings of the factory floors of Asia - bought on price rather than
performance. Try telling the customer this tho....

Andrew VK3BFA

The Keyword here is how 'bad' the tuner front end is Its probably a
tossup if there's a harmonic being received instead of a mixing beat but
at least tunable sets have a chance of getting away from it.

Here in the US, gear usually has options of off-air, cable, cable HRC
(harmonically related channels) or cable IRC (incrementally related
channels) . Depending on the freq of the FM station *sometimes* you can
force the set away from the FM harmonic by selecting one of the
oddballs. But if its beating with the video there's no cure.

Do you still have folks with rotary tuner sets down there? I haven't
seen one in a customer's home for 30 years on this side!

-Bill

Hi Bill, nope, not many left with rotary tuners (on UHF) - but I still
get called in to fix them occassionally, and even more so that some of
them still have good tubes in them!

Andrew VK3BFA