I've just been fitting TV aerials in two new houses - one a relative and
the other their new neighbour who saw what I was up to and wanted theirs
done too, for a few beer tokens..

Both jobs took longer than expected. The first was because the darling
builders had managed to get both the coax downleads to have whiskers of
braid wrapped round the core in the fitted TV/FM/SAT1+2/Return/Phone
socket in the living room. (This is quite nice, incidentally - two
downleads feed Sat2 and triplexed Sat1/TV/FM to 2x F connectors and two
UHF sockets on the twin faceplate, then a return lead takes your Sky+/
Cable/PVR UHF output back up to a bedroiom socket).

The second time, I was ready for the braid to be all over the place and
sorted that out first. Then I tried every combination going (on my own,
up and loft-ground floor in a 3 storey house loads of times) but
nothing I tried got a good signal. With my dying gasp I suspected whoever
wired it up was even worse than before and tried the 'return' cable, just
on the off chance. That was it.

Anyway, on to the point of the post ;-)

While looking for possible failure points, I checked out the (new) aerial
closely. The only electrical connections were to two alloy 'horns' near
the back which I guess the signal is focussed onto. Or rather, the
connections were to a small PCB inside the plastic box the horns came out
of. The horns were supposedly attached to the core of the coax by having
the PCB screwed down onto them - however the large contact pads that
would have touched them was still solidly covered in the non-conductive
varnish, and the screws went through the non-plated holes without joining
the two together electrically.

I measured to be sure - yup, no continuity. So I scraped some of the
varnish off and got a 1 ohm connection.

The question (finally) is this: was it designed to pass the energy by RF
coupling? Isn't that a bit lossy on what is a weak signal anyway?

And have I ballsed it up by connecting it electrically? I guess it could
have been some sort of lightning protection, but I can't see it being all
that effective, and it's in a loft now anyway...