This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly,
caused three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on
transmission speed and quality, and the fact that here, high up in west
suffolk, and hence potentially a target for windmills, we already have
half a dozen radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Nearly all mobile phone masts are fed via microwave. A HUGE amount of
data backbones are built out of them - a lot cheaper than fibre. And
although the towers occupy in general the highest ground around,
windmills reach even higher. They would inevitably be in many line of
sight beams' paths..


It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft, as well as effectively screening low flying aircraft from
radar, these things are likely to also totally disrupt any RF
frequencies in the VHF bands and up, that rely on line of sight
transmission to teh horizon.

Already the inlaws digital TV is totally disrupted by wet leaves on
trees blowing in the wind..the DSP algorithms can cope if the things are
static, but not if the multipath is constantly changing.

I know there are RF experts here. The question is, would a landscape
with a windmill every kilometre, actually be one in which any frequency
beyond short wave was usable?

"The Natural Philosopher" wrote in message
...

It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft, as well as effectively screening low flying aircraft from radar,
these things are likely to also totally disrupt any RF frequencies in the
VHF bands and up, that rely on line of sight transmission to teh horizon.

They are not dangerous to low flying aircraft, because if flying visually
you can see them and avoid them, and if flying on instruments you're a
thousand feet above them or on a properly surveyed instrument approach, and
"properly surveyed" includes taking account of obstacles, obviously. (Of
course if you're flying an unapproved GPS based DIY "instrument approach"
into a farm strip using an out of date GPS database which doesn't have last
week's wind farm in it then that's tantamount to suicide and not really
something for the rest of us to worry about.)

They do sometimes upset radars, and it's not unknown for a wind farm
developer to have to pay to upgrade radars.

You'd have to be doing some really bizarre low flying for them to get in the
way of line of sight VHF radio. Not something I've ever heard of being a
problem.

--
Tim Ward - posting as an individual unless otherwise clear
Brett Ward Limited - www.brettward.co.uk
Cambridge Accommodation Notice Board - www.brettward.co.uk/canb
Cambridge City Councillor

Tim Ward wrote:
"The Natural Philosopher" wrote in message
...
It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft, as well as effectively screening low flying aircraft from radar,
these things are likely to also totally disrupt any RF frequencies in the
VHF bands and up, that rely on line of sight transmission to teh horizon.

They are not dangerous to low flying aircraft, because if flying visually
you can see them and avoid them, and if flying on instruments you're a
thousand feet above them or on a properly surveyed instrument approach, and
"properly surveyed" includes taking account of obstacles, obviously.

You must come and sit in our back garden sometime, when the military
jets come over at 250' altitude. 100' is luxury for them.

And the microlights struggle to GET to 1000 ft sometimes

(Of
course if you're flying an unapproved GPS based DIY "instrument approach"
into a farm strip using an out of date GPS database which doesn't have last
week's wind farm in it then that's tantamount to suicide and not really
something for the rest of us to worry about.)

They do sometimes upset radars, and it's not unknown for a wind farm
developer to have to pay to upgrade radars.

You'd have to be doing some really bizarre low flying for them to get in the
way of line of sight VHF radio.

Er what? I am not sure my TC and FM reception requires me to get in an
aircraft..




Not something I've ever heard of being a
problem.

On Sun, 11 Oct 2009 12:33:42 +0100, Tim Ward wrote:

You'd have to be doing some really bizarre low flying for them to get in
the way of line of sight VHF radio. Not something I've ever heard of
being a problem.

Military. Was out with the RAF just before Gulf War I, they were
flying sorties out over the Saudi desert, they get seriously low when
in combat rather than excercise conditions. They were down to a few
tens of feet, camels were a hazard...

A wind turbine has a blade tip height of 350 to 400' the fast jets
round here are below that level. We look down on some of the slower
stuff, hercy birds and helos etc that are really hugging the ground.

Windmills do disrupt RF propagation it's not unknown for TV reception
to be disrupted if there is a windmill close to the path.

--
Cheers
Dave.

On 11 Oct, 12:15, The Natural Philosopher
wrote:

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Point-to-point microwave isn't arranged to run through windmills.

Broadcast microwave (i.e. cellphone) doesn't care. Diverse paths (the
relevant scale at these wavelengths is far smaller than the blades)
cope fine.

"The Natural Philosopher" wrote in message
...
This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly, caused
three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on transmission
speed and quality, and the fact that here, high up in west suffolk, and
hence potentially a target for windmills, we already have half a dozen
radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Nearly all mobile phone masts are fed via microwave. A HUGE amount of data
backbones are built out of them - a lot cheaper than fibre. And although
the towers occupy in general the highest ground around, windmills reach
even higher. They would inevitably be in many line of sight beams' paths..


It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft, as well as effectively screening low flying aircraft from radar,
these things are likely to also totally disrupt any RF frequencies in the
VHF bands and up, that rely on line of sight transmission to teh horizon.

Already the inlaws digital TV is totally disrupted by wet leaves on trees
blowing in the wind..the DSP algorithms can cope if the things are static,
but not if the multipath is constantly changing.

I know there are RF experts here. The question is, would a landscape with
a windmill every kilometre, actually be one in which any frequency beyond
short wave was usable?


I assume you are asking about the modern wind turbines rather than old
fashioned windmills. The former can, and do, cause disruption to RF links
and terrestrial TV. I live near to RNAS Yeovilton and they are a statutory
consultee for all large wind turbine planning applications. A contact there
tells me that they are concerned about the effect on their radar
installations as well as the implications for low flying. There have also
been reports in the press about disruption to terrestrial TV signals has
also been reported such as this link shows.

http://news.bbc.co.uk/1/hi/northern_ireland/8055487.stm

Peter Crosland

On 11 Oct, 12:15, The Natural Philosopher
wrote:

Nearly all mobile phone masts are fed via microwave. A HUGE amount of
data backbones are built out of them - a lot cheaper than fibre.

Rural, small-scale cellphone systems use microwave links. Bigger ones
don't. Now my knowledge here is rather outdated, but last time I
looked at this (I designed the software that designed the networks)
the limitation of the Abis interface (the daisy chained microwave
link) was sufficient that you could only daisy-chain a handful of
masts, and low-traffic masts at that, before you ran out of capacity.

A single "plastic stick up a pole" mast is an omnidirectional antenna
serving a single cell. Where there's substantial traffic though, a
mast (which is expensive) will be used to support two or three
directional antenna, with a cell either way from the mast. You can
also have multiple radios (and antennae) within a cell, increasing
cell capacity, and thus data needs, from that same mast.

Abis just wasn't designed to be capable of handling too many radios
worth of traffic, and the microwave links it uses are equally
restricted. Really it's only useful for single-radio, single cell per
mast networks, which is the rural end of things.


Also, although microwave links are cheaper than cabled links (as
links), they have paltry bandwidth compared to fibre. You just can't
put today's data rates over microwave. One reason why communications
satellites are now a niche market for where cabling is impractical,
rather than a first choice.

On Sun, 11 Oct 2009 05:38:40 -0700 (PDT), Andy Dingley wrote:

Point-to-point microwave isn't arranged to run through windmills.

But when the windmill pops up close to a pre existing link...

--
Cheers
Dave.

"The Natural Philosopher" wrote in message
...
This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly, caused
three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on transmission
speed and quality, and the fact that here, high up in west suffolk, and
hence potentially a target for windmills, we already have half a dozen
radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

We did a series of studies for one of the very large energy firms. The
studies concerned the likely effects of proposed windfarms on local tv
reception. As a result I had to read all the planning applications, and the
normal procedure was for the operators of any links anywhere near were
consulted and allowed to object.

In the case of the turbines near Parkway Sheffield I don't think the proper
procedures were follewed, by they normally are. The Sheffield turbines have
had another spectacular failure, by the way.

http://www.telegraph.co.uk/news/news...cond-time.html

Meanwhile they are allowing a turbine to be installed on a school playing
field, whilst banning cellphone towers. What a set of bloody idiots we have
running out local councils.

Bill

"The Natural Philosopher" wrote in message
...
This is a curious question, which I don't believe has been
asked before, and to which I couldn't actually find and answer.
And only being half asleep and thinking about one thing whilst
reading the paper idly, caused three things to slip into my
mind together.

Namely 'rural broadband' the influence of the environment on
transmission speed and quality, and the fact that here, high up
in west suffolk, and hence potentially a target for windmills,
we already have half a dozen radio towers dotted with aerials
and dishes.

So, how do presumably metal or carbon fibre blades thwacking
past or around a microwave tower affect its transmission and
reception?

Nearly all mobile phone masts are fed via microwave. A HUGE
amount of data backbones are built out of them - a lot cheaper
than fibre. And although the towers occupy in general the
highest ground around, windmills reach even higher. They would
inevitably be in many line of sight beams' paths..


It seems to me as well as being ugly, noisy, and dangerous to
low flying aircraft, as well as effectively screening low
flying aircraft from radar, these things are likely to also
totally disrupt any RF frequencies in the VHF bands and up,
that rely on line of sight transmission to teh horizon.

Already the inlaws digital TV is totally disrupted by wet
leaves on trees blowing in the wind..the DSP algorithms can
cope if the things are static, but not if the multipath is
constantly changing.

I know there are RF experts here. The question is, would a
landscape with a windmill every kilometre, actually be one in
which any frequency beyond short wave was usable?




Part of the application process to erect the turbines is that the
applicant must accertain if they are wishing to build in the path
of or very close to the path of any radio link, microwave or
otherwise. If there are any that will be affected they either
have to find an alternative location for the turbine(s) or pay
for the link to be replaced by fibre or for the link to be
rerouted - and of course they have to get the agreement of the
user to these changes. If there is no alternative path then the
application fails.

Simples.


--
Woody

harrogate three at ntlworld dot com

On 11 Oct, 13:59, "Dave Liquorice"
wrote:
On Sun, 11 Oct 2009 05:38:40 -0700 (PDT), Andy Dingley wrote:
Point-to-point microwave isn't arranged to run through windmills.

But when the windmill pops up close to a pre existing link...

That's supposed to be why we have planning permission for them, and
most likely some compensation to the link owner to rearrange it.

Besides which, this is a rare occurence. They both favour different
geographies, so there's relatively little chance of them crossing.

"Bill Wright" wrote in message
...

"The Natural Philosopher" wrote in message
...
This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly, caused
three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on transmission
speed and quality, and the fact that here, high up in west suffolk, and
hence potentially a target for windmills, we already have half a dozen
radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

We did a series of studies for one of the very large energy firms. The
studies concerned the likely effects of proposed windfarms on local tv
reception. As a result I had to read all the planning applications, and
the normal procedure was for the operators of any links anywhere near were
consulted and allowed to object.

In the case of the turbines near Parkway Sheffield I don't think the
proper procedures were follewed, by they normally are. The Sheffield
turbines have had another spectacular failure, by the way.

http://www.telegraph.co.uk/news/news...cond-time.html

Meanwhile they are allowing a turbine to be installed on a school playing
field, whilst banning cellphone towers. What a set of bloody idiots we
have running out local councils.

Bill

I was once asked to sign a petition by some women protesting at
the proposed site of a roadside cellphone mast. It was in front a gap
between two pairs of semis. I refused, and suggested they should
be more worried about what was currently buried under the site
filling the gap; a Shell forecourt.

--
Graham.

%Profound_observation%

Ask yourself this: -

If the blade passes in front of the sun, will it blot it out?

"The Natural Philosopher" wrote in message
...
This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly, caused
three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on transmission
speed and quality, and the fact that here, high up in west suffolk, and
hence potentially a target for windmills, we already have half a dozen
radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Nearly all mobile phone masts are fed via microwave. A HUGE amount of data
backbones are built out of them - a lot cheaper than fibre. And although
the towers occupy in general the highest ground around, windmills reach
even higher. They would inevitably be in many line of sight beams' paths..


It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft, as well as effectively screening low flying aircraft from radar,
these things are likely to also totally disrupt any RF frequencies in the
VHF bands and up, that rely on line of sight transmission to teh horizon.

Already the inlaws digital TV is totally disrupted by wet leaves on trees
blowing in the wind..the DSP algorithms can cope if the things are static,
but not if the multipath is constantly changing.

I know there are RF experts here. The question is, would a landscape with
a windmill every kilometre, actually be one in which any frequency beyond
short wave was usable?

On Sun, 11 Oct 2009 21:06:55 +0100, R. Mark Clayton wrote:

If the blade passes in front of the sun, will it blot it out?

Depends on how far you are from the blade. Flicker due to the moving
shadow of the blades is a serious problem. How would you like the
light level to drop every few seconds or so?

--
Cheers
Dave.

On Sun, 11 Oct 2009 14:48:26 +0100, Bill Wright wrote:

http://www.telegraph.co.uk/news/news.../6284573/Wind-
turbine-in-Sheffield-broken-by-wind-for-second-time.html

Curious that there are no pictures and the only news stories I can
find all relate back to the telegraph one, some just quoting it.

Two things spring to mind:

The Powers That Be have applied pressure on the media to either not
report it all or only give in minmal coverage.

It didn't happen.

--
Cheers
Dave.

Curious that there are no pictures and the only news stories I can
find all relate back to the telegraph one, some just quoting it.

possibly http://www.rotherhamadvertiser.com/news.aspx?id=9629 as they
have an earlier dateline

Two things spring to mind:

The Powers That Be have applied pressure on the media to either not
report it all or only give in minmal coverage.

Does anyone need to *apply* pressure when the media mostly know that
Govnt and wind turbine companies have advertising budgets while
opponents (mostly) don't?


--
R

"The Natural Philosopher" wrote in message
...
So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?


Not just microwave coms but TV and radar as well...

http://news.bbc.co.uk/1/hi/uk/7227967.stm

http://www.theregister.co.uk/2009/04/03/ofcom_wind/

http://www.bbc.co.uk/reception/info/windfarms.shtml

Cwatters wrote:
"The Natural Philosopher" wrote in message
...
So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?


Not just microwave coms but TV and radar as well...

http://news.bbc.co.uk/1/hi/uk/7227967.stm

http://www.theregister.co.uk/2009/04/03/ofcom_wind/

http://www.bbc.co.uk/reception/info/windfarms.shtml


Thank you for that. I think the register was the most thought provoking.

In article ,
The Natural Philosopher wrote:

This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly,
caused three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on
transmission speed and quality, and the fact that here, high up in west
suffolk, and hence potentially a target for windmills, we already have
half a dozen radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Nearly all mobile phone masts are fed via microwave. A HUGE amount of
data backbones are built out of them - a lot cheaper than fibre. And
although the towers occupy in general the highest ground around,
windmills reach even higher. They would inevitably be in many line of
sight beams' paths..

I don't get this view of wind turbines as being having some kind of
'special' powers to affect the environment; they are just structures.
Where microwaves are being used for point-to-point communication you
just do what you would do in an urban environment or in mountainous
regions: find a line of sight or create one by putting up a mast. These
a fixed structures and are not going to come waltzing in to view
unexpectedly. You figure out where they are and find a line-of-sight
accordingly. If your existing line-of-sight gets disrupted you move,
build higher or build another repeater to get around it. Not
rocket-science.

Espen Koht wrote:
In article ,
The Natural Philosopher wrote:

This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly,
caused three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on
transmission speed and quality, and the fact that here, high up in west
suffolk, and hence potentially a target for windmills, we already have
half a dozen radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Nearly all mobile phone masts are fed via microwave. A HUGE amount of
data backbones are built out of them - a lot cheaper than fibre. And
although the towers occupy in general the highest ground around,
windmills reach even higher. They would inevitably be in many line of
sight beams' paths..

I don't get this view of wind turbines as being having some kind of
'special' powers to affect the environment; they are just structures.
Where microwaves are being used for point-to-point communication you
just do what you would do in an urban environment or in mountainous
regions: find a line of sight or create one by putting up a mast. These
a fixed structures and are not going to come waltzing in to view
unexpectedly. You figure out where they are and find a line-of-sight
accordingly. If your existing line-of-sight gets disrupted you move,
build higher or build another repeater to get around it. Not
rocket-science.

Espen: the key here is the blades MOVE. And they are high up in
otherwise clear space.

We are quite smart in dealing with multipath from fixed objects..we are
far less so when the object moves.

Like wise doppler radar - the easiest way to pick low flying aircraft
out of ground clutter - can't cope with stuff moving at low level.

On Sun, 11 Oct 2009 14:48:26 +0100, "Bill Wright"
wrote:


In the case of the turbines near Parkway Sheffield I don't think the proper
procedures were follewed, by they normally are. The Sheffield turbines have
had another spectacular failure, by the way.

http://www.telegraph.co.uk/news/news...cond-time.html

Meanwhile they are allowing a turbine to be installed on a school playing
field, whilst banning cellphone towers. What a set of bloody idiots we have
running out local councils.


Meanwhile on a new school roof in Cleckheaton (All right, all right.
get it over with, it's not *that* funny) is adorned with the things
like candles on a birthday cake. they look to be about 3 metres in
diameter and about 5 metres high off the roof. (see website below).

The small matter of the boundary layer concerns me. No doubt when they
are finished and turn out not to generate anything like the power they
have been "designed" to do it will be portrayed as a failure of
British Engineering.

A similar project here ...

http://www.westandmachell.co.uk/projects.asp?cat1=4&cat2=14&mul=2


Derek

Dave Liquorice wrote:
On Sun, 11 Oct 2009 12:33:42 +0100, Tim Ward wrote:

You'd have to be doing some really bizarre low flying for them to get in
the way of line of sight VHF radio. Not something I've ever heard of
being a problem.

Military. Was out with the RAF just before Gulf War I, they were
flying sorties out over the Saudi desert, they get seriously low when
in combat rather than excercise conditions. They were down to a few
tens of feet, camels were a hazard...

I presume you are talking about Tornado here. They *can* fly damn low. I
know, I spent 20 odd years on their development. Rolls Royce (Turbo
Union) spent a lot of time developing the turbine blades so that the
sand didn't melt and clog up the tiny cooling holes in them.

A wind turbine has a blade tip height of 350 to 400' the fast jets
round here are below that level. We look down on some of the slower
stuff, hercy birds and helos etc that are really hugging the ground.

Son was a member of the crew of HMS Invincible a few years ago and they
held a families day aboard it. We took a sail around the Isle of Whight
and back to Portsmouth. One thing I enjoyed was the fly past by the
Hawk trainer aircraft. The first time I have ever seen them from above.
After that, I sat on the stern of the ship, feet dangling over the edge
and looking down at the wake. There is a net all around the deck so that
you would have to be very determined to jump and drown. Must be about 6
foot in width.

The aircraft's Harriers later left for servicing, but I stayed round the
back of the command tower, as I had seen plenty of those take off in my
job. Landing, they are good to see, if they perform.

Dave

On 12 Oct, 20:14, Derek Geldard wrote:

Meanwhile on a new school roof in Cleckheaton (All right, all right.
get it over with, it's not *that* funny) is adorned with the things
like candles on a birthday cake.

The rebuilt primary school behind our house has planning permission
for a small low-mounted vertical axis machine - small, but a quite
reasonable installation that should work well enough (within its size
limitations) on that site.

However the usual cost-cutting half-way through the project has
switched this for a cheaper horizontal axis machine. Which is more
sensitive to disturbed airflow, and so will be a waste of time and
effort.

On Tue, 13 Oct 2009 02:15:41 -0700, Andy Dingley wrote:
The rebuilt primary school behind our house has planning permission
for a small low-mounted vertical axis machine - small, but a quite
reasonable installation that should work well enough (within its size
limitations) on that site.

Urgh - I got that far and was impressed...

However the usual cost-cutting half-way through the project has
switched this for a cheaper horizontal axis machine.

.... then I continued reading

How come vertical axis is more expensive? Purely because horizontal is
more common? The blade weight seems roughly comparable - bearing load
is different, but I'm surprised it adds that much more to the cost...

On 13 Oct, 13:26, Jules
wrote:

How come vertical axis is more expensive? Purely because horizontal is
more common?

Partly, although that's changing.

AIUI, there are two sorts of vertical axis machine: those that put
one hell of an oscillating load on their (thus expensive) supports as
they rotate, and those with complicated twisted blade designs that are
easier to support, but need more costly ways to make the blades.

Mind you, if you want to see the horribly inflated cost of machining
anything these days if the volume's small, take a look at the GWR
Railmotor reconstruction period and the prices their connecting and
motion rods were costing.

On Mon, 12 Oct 2009 22:43:03 +0100, Dave wrote:

Military. Was out with the RAF just before Gulf War I, they were
flying sorties out over the Saudi desert, they get seriously low
when
in combat rather than excercise conditions. They were down to a
few
tens of feet, camels were a hazard...

I presume you are talking about Tornado here. They *can* fly damn low.

Yep, "The Crater Makers" ... Which is why we lost so many aircraft
out there.

--
Cheers
Dave.

On 14 Oct, 23:19, "Dave Liquorice"
wrote:

I presume you are talking about Tornado here. They *can* fly damn low.

Yep, "The Crater Makers" ... Which is why we lost so many aircraft
out there.

9 lost Tornados: 3 (ZD718, ZA392, ZA467) by reasonable possibility of
controlled flight into ground. Of the others, 3 were SAMs, 3 were
various technical problems.

On Oct 11, 12:58*pm, "Dave Liquorice"
wrote:
they were flying sorties out over the Saudi desert, they get seriously low
when in combat rather than excercise conditions. They were down to a
few tens of feet, camels were a hazard...

Indeed; defined safe box & safe altitude against friendly; extreme low
height to avoid radar particularly SAM. Saudi, Iraq etc are hugely
hard on sand filters used to protect turbines - the maintenance is
pretty severe. Helo lift off is get going horizontally as fast as
possible and worry about altitude once you get airspeed up, so sand
gets everywhere.

The obsession with low flying in the UK is a necessity I'm afraid, pay
the penalty in noise now or lives later in exercises or combat (plus
those on the ground from failed sortie to provide air cover).

The small vertical axis wind turbines can operate at high speed &
produce a very loud whirring noise. They are not pleasant at close
quarters, both visually & acoustically.

The Natural Philosopher wrote:

It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft

Any aircraft flying that low, if not intending to land would be in
breach of the Air Navigation Order even in VMC.

http://www.opsi.gov.uk/si/si2005/20051970.htm

also

http://www.caa.co.uk/docs/33/ga_srg_09webSSL05.pdf

4 PLANNING THE ROUTE
e)........Do not plan to fly below
1500 ft AGL; it hides features, you
may meet high speed military aircraft
(see Safety Sense Leaflet No. 18
‘Military Low Flying’), and it reduces
options in the event of engine failure.


Graham

On Thu, 15 Oct 2009 19:50:39 +0100, Eeyore wrote:

4 PLANNING THE ROUTE
e)........Do not plan to fly below 1500 ft AGL; it hides features, you
may meet high speed military aircraft (see Safety Sense Leaflet No. 18
Military Low Flying ), and it reduces options in the event of engine
failure.

Which implies that fast jets are below 1500'. IIRC they are allowed
down to 500' more or less anywhere over the country and 250' is some
areas. Helicopters can go lower, 50'?

The 2MW turbines that initial work was done on planting near here
would have had a blade tip height of 350'. The jets come over well
below that, we can see them well enough to wave at the pilots. The
Blue Meanies don't wave back though. B-)

--
Cheers
Dave.

Eeyore wrote:
The Natural Philosopher wrote:

It seems to me as well as being ugly, noisy, and dangerous to low
flying aircraft

Any aircraft flying that low, if not intending to land would be in
breach of the Air Navigation Order even in VMC.

http://www.opsi.gov.uk/si/si2005/20051970.htm

also

http://www.caa.co.uk/docs/33/ga_srg_09webSSL05.pdf


Oh the private boys are fine. Even the microlights tend to be about
1000ft plus. The military do not though. 4-600 feet and the
helicopters...yeah well.


4 PLANNING THE ROUTE
e)........Do not plan to fly below
1500 ft AGL; it hides features, you
may meet high speed military aircraft
(see Safety Sense Leaflet No. 18
‘Military Low Flying’), and it reduces
options in the event of engine failure.


Exactly. the military owns sub 1500, and thats where the mills will go.

Graham

Huge wrote:
On 2009-10-15, Dave Liquorice wrote:
On Thu, 15 Oct 2009 19:50:39 +0100, Eeyore wrote:

4 PLANNING THE ROUTE
e)........Do not plan to fly below 1500 ft AGL; it hides features, you
may meet high speed military aircraft (see Safety Sense Leaflet No. 18
Military Low Flying ), and it reduces options in the event of engine
failure.
Which implies that fast jets are below 1500'. IIRC they are allowed
down to 500' more or less anywhere over the country and 250' is some
areas. Helicopters can go lower, 50'?

No matter what the rules say, the military, by my direct observation, fly
as low as they physically can. And if you ring to complain the MoD call
you a liar (Ok, they say "we do not have any aircraft operating in that
area", which is the same thing.)


"They have already left that area, so technically, this is not a lie"

Pilots will be pilots, and under the radar approaches are part of the
training..

I've looked DOWN on aircraft flying up the valleys in snowdonia, and
found a crashed military helicopter up a mountain.

On 16 Oct 2009 09:17:12 GMT, Huge wrote:

No matter what the rules say, the military, by my direct observation,
fly as low as they physically can.

Round here they have a problem that the land rises rather faster than
they can without putting one rather more power than they want to. I
guess being a white building on a promontory that forms a bend in the
valley also makes us a bit of way marker. Leave Warcop, up Teesdale
(ish), over the watershed between the Tees and South Tyne, drop down
into the South Tyne Valley and aim for the white blob on the hill 3
miles away as you'll be there in 20s, then exit enroute for
Spadeadam. B-)

And if you ring to complain the MoD call you a liar (Ok, they say "we do
not have any aircraft operating in that area", which is the same thing.)

The time I complained by phone I was pleased by the response both on
the phone and by letter a while later. Nothing really happened that I
was aware of course. I complained that there had been a fast jet
going one way over the town and then a matter of a few seconds later
one went in the opposite direction at the same level. They do
occasionally dog fight over us but they normally do that at 1000'
and it is impressive to watch 4 fast jets trying to out maneuver each
other.

--
Cheers
Dave.

Dave Liquorice wrote:

The time I complained by phone I was pleased by the response both on
the phone and by letter a while later. Nothing really happened that I
was aware of course. I complained that there had been a fast jet
going one way over the town and then a matter of a few seconds later
one went in the opposite direction at the same level. They do
occasionally dog fight over us but they normally do that at 1000'
and it is impressive to watch 4 fast jets trying to out maneuver each
other.


Did you hear that story about the farmer who painted "F**** OFF BIGGLES"
on his barn roof? Apparently every fast jet in the country went to look...

Andy

On Fri, 16 Oct 2009 20:44:35 +0100, Andy Champ wrote:

Did you hear that story about the farmer who painted "F**** OFF BIGGLES"
on his barn roof? Apparently every fast jet in the country went to
look...

B-)

I'm tempted to put a big upward pointing arrow head with the words
"PULL UP" on the gable end that faces up the valley. I don't want it
visible to ordinary people though just the Blue Meanies so something
to alter the infrared signature of parts of the stone wall. Any
ideas?

--
Cheers
Dave.

"Dave Liquorice" wrote in message
ll.co.uk...
On Fri, 16 Oct 2009 20:44:35 +0100, Andy Champ wrote:

Did you hear that story about the farmer who painted "F**** OFF BIGGLES"
on his barn roof? Apparently every fast jet in the country went to
look...

B-)

I'm tempted to put a big upward pointing arrow head with the words
"PULL UP" on the gable end that faces up the valley. I don't want it
visible to ordinary people though just the Blue Meanies so something
to alter the infrared signature of parts of the stone wall. Any
ideas?

Stick some "window" to the wall to interfere with the terrain following
radar.

Dave Liquorice wrote:
On Fri, 16 Oct 2009 20:44:35 +0100, Andy Champ wrote:

Did you hear that story about the farmer who painted "F**** OFF BIGGLES"
on his barn roof? Apparently every fast jet in the country went to
look...

B-)

I'm tempted to put a big upward pointing arrow head with the words
"PULL UP" on the gable end that faces up the valley. I don't want it
visible to ordinary people though just the Blue Meanies so something
to alter the infrared signature of parts of the stone wall. Any
ideas?


Whole-wall IR LED display, programmable with your MOTD.


--
Ian White

On Sat, 17 Oct 2009 07:50:46 +0100, Ian White wrote:

something to alter the infrared signature of parts of the stone
wall.
Any ideas?

Whole-wall IR LED display, programmable with your MOTD.

That appeals but not to the wallet. B-)

Don't really need to emit IR(*) though just alter the heat signature
of parts of the wall. Would black paint under the white do that?

(*) I don't want to dazzle the night vision camera as they fly up the
valley towards us at 500mph...

--
Cheers
Dave.

On 11 Oct, 12:15, The Natural Philosopher
wrote:
This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly,
caused three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on
transmission speed and quality, and the fact that here, high up in west
suffolk, and hence potentially *a target for windmills, we already have
half a dozen radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Nearly all mobile phone masts are fed via microwave. A HUGE amount of
data backbones are built out of them - a lot cheaper than fibre. And
although the towers occupy in general the highest ground around,
windmills reach even higher. They would inevitably be in many line of
sight beams' paths..

It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft, as well as effectively screening low flying aircraft from
radar, these things are likely to also totally disrupt any RF
frequencies in the VHF bands and up, that rely on line of sight
transmission to teh horizon.

Already the inlaws digital TV is totally disrupted by wet leaves on
trees blowing in the wind..the DSP algorithms can cope if the things are
static, but not if the multipath is constantly changing.

I know there are RF experts here. The question is, would a landscape
with a windmill every kilometre, actually be one in which any frequency
beyond short wave was usable?

A very interesting question, hope someone can reply!
Lyndsay

On 11 Oct, 12:15, The Natural Philosopher
wrote:
This is a curious question, which I don't believe has been asked before,
and to which I couldn't actually find and answer. And only being half
asleep and thinking about one thing whilst reading the paper idly,
caused three things to slip into my mind together.

Namely 'rural broadband' the influence of the environment on
transmission speed and quality, and the fact that here, high up in west
suffolk, and hence potentially *a target for windmills, we already have
half a dozen radio towers dotted with aerials and dishes.

So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?

Nearly all mobile phone masts are fed via microwave. A HUGE amount of
data backbones are built out of them - a lot cheaper than fibre. And
although the towers occupy in general the highest ground around,
windmills reach even higher. They would inevitably be in many line of
sight beams' paths..

It seems to me as well as being ugly, noisy, and dangerous to low flying
aircraft, as well as effectively screening low flying aircraft from
radar, these things are likely to also totally disrupt any RF
frequencies in the VHF bands and up, that rely on line of sight
transmission to teh horizon.

Already the inlaws digital TV is totally disrupted by wet leaves on
trees blowing in the wind..the DSP algorithms can cope if the things are
static, but not if the multipath is constantly changing.

I know there are RF experts here. The question is, would a landscape
with a windmill every kilometre, actually be one in which any frequency
beyond short wave was usable?

http://news.bbc.co.uk/1/hi/sci/tech/8320622.stm

special paint stops some interference
lyn