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[email protected] October 31st 05 11:38 AM
External Aerial fixing query
 
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.

Mungo

[email protected] October 31st 05 12:11 PM
External Aerial fixing query
 
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.

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.

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.

--
Chris Green

[email protected] October 31st 05 02:37 PM
External Aerial fixing query
 
Thanks Chris.
I thought that there was a factor of ten between inside the roof and
outside
the roof?
My motive for the move is to do with Digital TV: there's no point in
amplifying rubbish
(but enough of "Channel Five" :-) so the move outside was my next ploy.
Ta again

Mungo

P.S. For "better aerial" what is your suggestion (and source) please?

[email protected] October 31st 05 02:43 PM
External Aerial fixing query
 
wrote:
Thanks Chris.
I thought that there was a factor of ten between inside the roof and
outside
the roof?

maybe with a steel roof.

NT

Chris Bacon October 31st 05 03:09 PM
External Aerial fixing query
 
mungoh wrote:
I thought that there was a factor of ten between inside the roof and
outside the roof?

I looked at http://www.wrightsaerials.tv/, which I saw here, or
some digital TV group - there's some good stuff there, for instance:
http://www.wrightsaerials.tv/digitalterrtvrecep.htm. There's also
http://www.wolfbane.com/cgi-bin/tvd.exe? and so on.

[email protected] October 31st 05 03:19 PM
External Aerial fixing query
 
wrote:
Thanks Chris.
I thought that there was a factor of ten between inside the roof and
outside
the roof?
My motive for the move is to do with Digital TV: there's no point in
amplifying rubbish
(but enough of "Channel Five" :-) so the move outside was my next ploy.
Ta again

I'm not really an authority on this, you'd be better off asking in
uk.tech.digital-tv.

You may be limited by what will fit, it's not a good thing if the
aerial is very close to the roof as you get all sorts of odd effects
and it becomes difficult to position it.

Go to uk.tech.digital-tv and describe what you already have and I'm
sure you'll get (some) reasonable answers suggesting what may be
better.

BTW are you sure your existing aerial covers the right frequencies for
the digital MUXes your using? If it was just the existing analogue
aerial it might be that simply changing to a similar one that covers
the right frequencies will improve things enough.

--
Chris Green

The Natural Philosopher November 1st 05 12:52 AM
External Aerial fixing query
 
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.

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.

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.

^^^^^^^^^^^^^^^^^^^^^^^^^^^
My experience in a nutshell.

The only advantage in going outside is greater height and a room for a
bigger array. = Bloody Ugly.

Get the biggest loft aerial you can, take a little telly up in the loft
and bugger around till you get best analogue reception (fewest ghosts,
best signal) and then it its ghost free but weak, get a mast head amp or
loftbox. If its ghosty, get a better aerial.

Then go digital and lose all the ghosts.

Of course if your thatch is covered in chicken wire and your gables in
rendred metal mesh...you have little choice..unles your extension is
tiled PHEW!!

The Natural Philosopher November 1st 05 12:57 AM
External Aerial fixing query
 
wrote:

Thanks Chris.
I thought that there was a factor of ten between inside the roof and
outside
the roof?

No. Noth that bad. A wet roof with rain running down it is a bit poor,
but so is a rainstorm btetween you and the transmitter. Tiles and slates
are not bad at all at 450Mhz or whatever..its a different story at
satelliert freqencies tho.



My motive for the move is to do with Digital TV: there's no point in
amplifying rubbish
(but enough of "Channel Five" :-) so the move outside was my next ploy.

Thats what I had - great 1-4, poorish 5 (low power) so Istuck in te
biggest loft array I coudl get in the space and it showe up OKish on C5,
brilliant on 1-4..and basically used a distribution amp on the back -
didn;t imprive the picture, but allowed me to feed 10TV and radio sockets.

Got a digibox later on, stick it on, and voila. Perfect reception on
everything, (as far as digital recpetion is ever 'perfect') including
C5..only difference is the noisy thermostats instead of shoving white
dots on the screen, pixellate the whole picture...

Still BBC3 and Little Britan soon made me forget that...
Ta again

Mungo

P.S. For "better aerial" what is your suggestion (and source) please?

The Natural Philosopher November 1st 05 01:02 AM
External Aerial fixing query
 
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...

The Natural Philosopher November 1st 05 01:12 AM
External Aerial fixing query
 
Chris Bacon wrote:

mungoh wrote:

I thought that there was a factor of ten between inside the roof and
outside the roof?


I looked at http://www.wrightsaerials.tv/, which I saw here, or
some digital TV group - there's some good stuff there, for instance:
http://www.wrightsaerials.tv/digitalterrtvrecep.htm.

That is a most excellent bit of nettery...

There's also
http://www.wolfbane.com/cgi-bin/tvd.exe? and so on.

That says 'amplified extra high gain' - well I didn't need THAT.

Andy Luckman (AJL Electronics) November 1st 05 08:34 AM
External Aerial fixing query
 
In article ,
wrote:


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.

WRONG.

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.

Setting up a digital grade aerial is not a matter of waving a few bits of
aluminium in the breeze. All you need is a conformant aerial and cable,
installed properly to the spec laid down. Then it will work correctly.


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.

The attenuation is NOT your problem. You have reflections.


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,

Proving the reflections are an issue.



--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

Andy Luckman (AJL Electronics) November 1st 05 08:37 AM
External Aerial fixing query
 
In article ,
The Natural Philosopher wrote:

My experience in a nutshell.

The only advantage in going outside is greater height and a room for a
bigger array.

My 25 year experience.

Don't even consider loft aerials.

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

[email protected] November 1st 05 12:23 PM
External Aerial fixing query
 
"Andy Luckman (AJL Electronics)" wrote:

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,

Proving the reflections are an issue.

Yes, but having dealt with that issue by positioning the aerial
the loft aerial performed just as well as the outdoor aerial. It
*may* be that you can't avoid the issue completely in which case an
outdoor aerial may be the answer but just saying 'outdoor is always
best and much better than loft' is simply not true. Other people here
have said this too.

I think one factor may be that a commercial/professional installer doesn't
have the time (or patience) to spend a lot of time crawling around in
a loft to install an aerial in the best position there. They are much
more set up to quickly gain access to the roof and/or a chimney and can
get a reliable installation more easily that way.

A D-I-Y installer on the other hand probably doesn't have the
equipment or skills to work up on the roof or by a chimney, but they
*do* have more time (and maybe 'sympathy' with the surroundings) to do
a good loft installation.

--
Chris Green

The Natural Philosopher November 1st 05 01:03 PM
External Aerial fixing query
 
Andy Luckman (AJL Electronics) wrote:

In article ,
The Natural Philosopher wrote:


My experience in a nutshell.

The only advantage in going outside is greater height and a room for a
bigger array.


My 25 year experience.

Don't even consider loft aerials.


Oh. So I must take out a perfectly good working setup and ruin my
house's appearance becuase your 25 years experience of being unable to
rig a loft aerial properly tells me so?

I bet you voted Laber, too...

[email protected] November 1st 05 01:38 PM
External Aerial fixing query
 

Andy Luckman (AJL Electronics) wrote:
In article ,
The Natural Philosopher wrote:

My experience in a nutshell.

The only advantage in going outside is greater height and a room for a
bigger array.

My 25 year experience.

Don't even consider loft aerials.

Most of the houses I've lived in for the past 40 years have had loft
aerials. It's never been a problem for me.

My advice to a DIYer is try the loft first. If it's no good you haven't
lost anything and you may save a packet.

MBQ

The Natural Philosopher November 2nd 05 12:43 PM
External Aerial fixing query
 
wrote:

Andy Luckman (AJL Electronics) wrote:

In article ,
The Natural Philosopher wrote:


My experience in a nutshell.

The only advantage in going outside is greater height and a room for a
bigger array.

My 25 year experience.

Don't even consider loft aerials.


Most of the houses I've lived in for the past 40 years have had loft
aerials. It's never been a problem for me.

My advice to a DIYer is try the loft first. If it's no good you haven't
lost anything and you may save a packet.


Hear hear.

The requiremenst to get in and out and hacve a satisfactory aerial
installed in double quick time with good relaible reception means that
about 10-20% of the time a loft won't work. That is enough of a risk for
the average pro installer to not do it.

For DIOY, a decent narrow beam wideband aerial often does work.

Aerials are very inexpensive..if it doesn't work inside..put it outside.


MBQ


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