DIYbanter - View Single Post

wrote:

On 31 Oct,
wrote:

wrote:

Hi Folks,
I'm planning to move my in-the-loft telly aerial outside of the loft
and
the present thought is to attach the aerial to the side of a dormer
window.
The dormer is nothing special, but I am not sure which bits of metal
I'll
need to do the attaching. Screwfix shows various "cranks" (page 278 of
autumn 2005 catalogue 79), but since I've
never done this before it's time to engage the good advice of the folks
here.

I guess I'll need the "wall fixing kit" (but it will be attached to the
wooden side of the dormer) but beyond that would one of the offset
cranks
be enough to keep the aerial proud of the dormer?

Advice requested; thanks in advance.

My advice is don't bother. I suspect that a better aerial in the loft
will make far more difference than moving the existing aerial outside.

I moved my loft aerial outside a few months ago and the improvement is
negligable, I've gone from fairly good digital reception with the
occasional droput to fairly good digital reception with the occasional
droput. I also couldn't see much difference in the signal level
indicated by the STB's signal strength display.

If the signal is adequate in the loft, leave it. The aerial is protected from
the weather there. Putting a better aerial there is often counter productive,
as the surrounding objects are more likely to de-tune it, making it's gain
less than optimum.

Its not so much gain that one wants, as extremely narrow beam width to
reject all the multipath from tanks and pipes...and the neigbours tanks
and pipes..I used a long multi element Yagi..no neighhbourts hough, but
it did help reject some of the continental stuff that sometimes comes in
ALMOST from the same direction as Sudbury.

The aerial is now a couple of feet higher than it was when inside and the
downlead is no longer. I think rooves attenuate the signal less than the
'rules' suggest, maybe it depends on the roof a bit, ours is just an
ordinary tiled roof.

Depends on roof construction. some red tiles completely obliterate the
signal. My gable does in places where it is externally clad in wood.

Really? Never had that. Nor wood. Metal lath however...and wall ties..

The one thing that improved was the ease of setting up as I didn't have to
position the aerial quite so carefully when it was outside, not from the
direction point of view, when it was in the loft there were some 'holes'
due to reflections/standing waves.

It's much closer to spec when in 'free space' outside, but will suffer from
windage/corrosion more than inside. Being higher outside may clear local
obstuctions and is separated by the roof from home generated sources of
interference too, which may reduce dropouts on digital reception.

Provided you have a better than about 15dB signal to ghost/crap ratio,
digital is rock solid.

My only problesm are some cheap thermostats that spark when
switching..sound orrible on te radio...must replace...