On Mon, 11 Apr 2011 19:41:01 +0100, John Williamson
wrote:

MM wrote:
Snip
Initially, I tried setting up the TV in the living room, the one place
where the picture was grainy on the analogue portable. The LCD TV said
"weak or no signal".

Which proves you have a cable related fault. Or, as an outside chance, a
fault on the distribution amplifier. But you've tried swapping the
connections round at the amplifier end?

Yes. No diff.


So there's definitely a problem there. To cease with the guess-work I
have measured the actual length of the cable from the amplifier to the
wall plate: 13 metres +/- 20cm

The length to the kitchen wall plate is a lot shorter. I haven't
measured it, but it'll be about 6m

Which, with undamaged cable and a decent joint at each end will make sod
all difference. If one had been 50 metres and the other a couple of
metres, maybe you'd see a difference you could show with a meter.

You mean, the 13 metre distance should be fine, yes? (I mean, to the
living room wall plate.)

Does it make a difference that there is another unconnected aerial
cable in the same conduit? What they did on constructing the house is
plan for a satellite dish in case the buyer might eventually want one,
so they left a lengthy coil of aerial cable (presumably the CT100 that
has been referred to in this thread) in the corner in the living room.
This is routed up though the same conduit in which the said 13m length
of cable from the loft-mounted amplifier is routed. I just wondered if
there mightn't be some sort of interference between the two cables,
the "loose" unconnected roll and the one connected to the wall plate.

Note that this "spare" roll of cable is taken up into the loft through
the conduit and then there is another generous length of it lying
around for any future satellite dish installer to make use of.

MM