"Bazzer Smith" wrote in message
...

"Bill Wright" wrote in message
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"Bazzer Smith" wrote in message
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Worked quite well second time. (the post formatting I mean).

The amp will have two stages with a variable attenuator between them. It
sounds as if one stage is not working.

Connecting two aerials and achieving a correct phase relationship is
impossible in a loft, because the surroundings affect the behaviour of
each aerial so much.


Yes I thought that might be a problem, however I wil have one more try at
it
anyway because I think I had my aerials 180% out of phase inittialy so its
worth one more try.


My dear Basil, I'd love to show you how it is possible to get two aerial
exactly in phase, then move the nulls around by altering the distance
between them. When I do it it's sheer poetry. Have you seen Fred Astaire
dance? Well that's me on a big roof with a stacked or bayed array. When
it's windy I can even detect Emley Moor's sway. At this moment I'm
listening to the London Symphony Orchestra working their way through a
few Beethoven Concertos. Those boys have got nothing on me when I've got
a pair of TC18s to play with.

Bill



Well I had another go at it with partial success, I could get some muxes but
not others, I was getting good analogue pictures up in the loft (a little
ghosting) so I had high hopes for the digital stuff.
(I didn't bother taking the set top box in) but overall it is not good
enough
So I have reverted back to one aerial. I am pretty sure I had the aerials
180 degrees out of phase, basically one aerial was 'upside down' (I think).
Interestingly I left the other aerial in position but disconnected it and it
seems
to have improved the overall signal levels!! My weakest mux is 91% all the
others are 98% (the max I have ever had).


I am now thinking I might have more luck with a proper aerial combiner
because having two aerials connected seems to have a similar effect to
splitting the signal at the other end. (in that I lose two muxes), however
I think there is a fair bit of reflection going on up there so it may well
be nigh on impossible to get all 6 muxes.
Anyway I think I will get a £15 four way booster from Argos and a passive
spplitter that should be the easiest solution