Dishes and wind


John Lemay
 

I have two mesh dishes on my mast. It's not obvious (to me) whether to point
them facing the prevailing wind, away from it, or somewhere else.

What's the usual practice ?

I'm not keen on luffing the mast because not everything is totally
weatherproof when it isn't upright.

Thanks

John G4ZTR


John Quarmby
 

A good question! Pointing the dishes into the wind balances the torque on the rotator, but results in maximum wind load on the stub mast. Setting the dishes so the wind blows across the face of the dish reduces wind loading overall but increases the stress on the rotator. So either might be correct depending on the relative strength of the mast and braking torque of the rotator. Like you I haven't luffed over as that compromises the weather proofing.

I rather suspect I won't be coming on for tomorrow night's 70cm UKAC, with winds up to 60mph forecast here.

73

John G3XDY

On 13/01/2020 19:46, John Lemay wrote:
I have two mesh dishes on my mast. It's not obvious (to me) whether to point
them facing the prevailing wind, away from it, or somewhere else.

What's the usual practice ?

I'm not keen on luffing the mast because not everything is totally
weatherproof when it isn't upright.

Thanks

John G4ZTR



Paul G8KFW
 

Hi john
As the wind is not constantly in the same direction and you are not there to
monitor it I personally would have the wind hitting the back of the dish

With the back to the wind the wind can skim over the outside causing less
force to the mounting metalwork
The problem hear is the method of mounting as the mounting bolts can putt
through the dish skin

as your dish is a mesh type I would think this is your safest option

If you had automatic control you could go for nearly side on but the
tenderncy is the dish can act as a wing of an aircraft and push back on the
mountings

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of
John Lemay
Sent: 13 January 2020 19:46
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Dishes and wind

I have two mesh dishes on my mast. It's not obvious (to me) whether to point
them facing the prevailing wind, away from it, or somewhere else.

What's the usual practice ?

I'm not keen on luffing the mast because not everything is totally
weatherproof when it isn't upright.

Thanks

John G4ZTR







-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.



--
Paul Bicknell G8KFW   South Coast UK


Ralph
 

Hello John,

 

I  point my dish so it looks down wind .

As we get many strorms and strong gales

In the SW It has proved fine for me, but

Some people may suggest differently hi.

 

73

 

Ralph

 

Sent from Mail for Windows 10

 

From: John Lemay
Sent: 13 January 2020 19:47
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Dishes and wind

 

I have two mesh dishes on my mast. It's not obvious (to me) whether to point

them facing the prevailing wind, away from it, or somewhere else.

 

What's the usual practice ?

 

I'm not keen on luffing the mast because not everything is totally

weatherproof when it isn't upright.

 

Thanks

 

John G4ZTR

 

 

 

 


Chris Bartram G4DGU <chris@...>
 

I've recently been working on the design of a new mast system and I want it to support a reasonable dish for terrestrial operation. A lattice tower wouldn't be appropriate here, and I need something a bit better than a beefed-up domestic installation. I also need easy access to the antennas. As I've never been particularly interested in 2.3, 3.4, and 5.6GHz, I plan to use a domestic 1 or 1.2m offset dish with an efficient dual-band 1.3/10GHz feed. A snake yagi would be unlikely to survive for very long here.

Living in Cornwall where it's intrinsically windy, at a location which is also subject to katabatic winds falling off the range of hills on which the GB3MCB beacons sit, I've been looking at the problems from first principles. This seems to be an everyday problem on a par with circuit analysis for structural engineers ... My initial reading of a number of sources does seem to suggest that a worst case calculation of the force developed by the wind on a dish antenna is something which isn't that difficult to perform: the principles behind the building regulations take into account the aerodynamics of the dish in arriving at their figures.

One very relevant point - which I have seen made in amateur radio publications, but which doesn't seem to be generally appreciated here - is that mesh dishes aren't that much better in terms of wind loading than than solid dishes of the same diameter at higher windspeeds. The difference seems to equate to a small penalty in dish diameter and the increased efficiency of the solid dish probably counteracts that.

I hope these comments are useful: I'll probably understand this a lot better with further reading, so please treat them as provisional!

73

Chris

G4DGU


John Lemay
 

Firstly, many thanks for the helpful comments yesterday. I went with my gut feeling, and pointed the dishes downwind, and all was well. There's more to come later today, probably worse than yesterday here if the forecast is correct.

My larger dish (2m diameter) is home designed and home built, so I have plenty of interest in its survival !

Chris -

I've read the same web pages as you have by the sound of it, regarding wind loading of mesh dishes v solid dishes. And I'm not convinced. But it occurs to me that we should be considering not two types of construction, but three types. These are solid, perforated material, and mesh. If we compare solid and perforated material I can understand that the difference in wind load is not great; I'm looking at a sample sheet of perforated aluminium and the holes probably represent 30% of the area. But with mesh (like RF HamDesign dishes) the gaps represent 70 to 90% of the area, depending on the mesh option chosen.

Nothing is simple, is it ?

Regards

John G4ZTR

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Chris Bartram G4DGU
Sent: 14 January 2020 10:50
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

I've recently been working on the design of a new mast system and I want
it to support a reasonable dish for terrestrial operation. A lattice
tower wouldn't be appropriate here, and I need something a bit better
than a beefed-up domestic installation. I also need easy access to the
antennas. As I've never been particularly interested in 2.3, 3.4, and
5.6GHz, I plan to use a domestic 1 or 1.2m offset dish with an efficient
dual-band 1.3/10GHz feed. A snake yagi would be unlikely to survive for
very long here.

Living in Cornwall where it's intrinsically windy, at a location which
is also subject to katabatic winds falling off the range of hills on
which the GB3MCB beacons sit, I've been looking at the problems from
first principles. This seems to be an everyday problem on a par with
circuit analysis for structural engineers ... My initial reading of a
number of sources does seem to suggest that a worst case calculation of
the force developed by the wind on a dish antenna is something which
isn't that difficult to perform: the principles behind the building
regulations take into account the aerodynamics of the dish in arriving
at their figures.

One very relevant point - which I have seen made in amateur radio
publications, but which doesn't seem to be generally appreciated here -
is that mesh dishes aren't that much better in terms of wind loading
than than solid dishes of the same diameter at higher windspeeds. The
difference seems to equate to a small penalty in dish diameter and the
increased efficiency of the solid dish probably counteracts that.

I hope these comments are useful: I'll probably understand this a lot
better with further reading, so please treat them as provisional!

73

Chris

G4DGU


Andy G4JNT
 

On mesh dishes, isn't it all about turbulence around the (thin) mesh conductive elements causing a much greater effective thickness?

But I don't even try to understand mechanical things, and just quoting summat I read yonks ago mixed with a gut feeling.



On Tue, 14 Jan 2020 at 11:20, John Lemay <john@...> wrote:
Firstly, many thanks for the helpful comments yesterday. I went with my gut feeling, and pointed the dishes downwind, and all was well. There's more to come later today, probably worse than yesterday here if the forecast is correct.

My larger dish (2m diameter) is home designed and home built, so I have plenty of interest in its survival !

Chris -

I've read the same web pages as you have by the sound of it, regarding wind loading of mesh dishes v solid dishes. And I'm not convinced. But it occurs to me that we should be considering not two types of construction, but three types. These are solid, perforated material, and mesh. If we compare solid and perforated material I can understand that the difference in wind load is not great; I'm looking at a sample sheet of perforated aluminium and the holes probably represent 30% of the area. But with mesh (like RF HamDesign dishes) the gaps represent 70 to 90% of the area, depending on the mesh option chosen.

Nothing is simple, is it ?

Regards

John G4ZTR


-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Chris Bartram G4DGU
Sent: 14 January 2020 10:50
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

I've recently been working on the design of a new mast system and I want
it to support a reasonable dish for terrestrial operation. A lattice
tower wouldn't be appropriate here, and I need something a bit better
than a beefed-up domestic installation. I also need easy access to the
antennas. As I've never been particularly interested in 2.3, 3.4, and
5.6GHz, I plan to use a domestic 1 or 1.2m offset dish with an efficient
dual-band 1.3/10GHz feed. A snake yagi would be unlikely to survive for
very long here.

Living in Cornwall where it's intrinsically windy, at a location which
is also subject to katabatic winds falling off the range of hills on
which the GB3MCB beacons sit, I've been looking at the problems from
first principles. This seems to be an everyday problem on a par with
circuit analysis for structural engineers ... My initial reading of a
number of sources does seem to suggest that a worst case calculation of
the force developed by the wind on a dish antenna is something which
isn't that difficult to perform: the principles behind the building
regulations take into account the aerodynamics of the dish in arriving
at their figures.

One very relevant point - which I have seen made in amateur radio
publications, but which doesn't seem to be generally appreciated here -
is that mesh dishes aren't that much better in terms of wind loading
than than solid dishes of the same diameter at higher windspeeds. The
difference seems to equate to a small penalty in dish diameter and the
increased efficiency of the solid dish probably counteracts that.

I hope these comments are useful: I'll probably understand this a lot
better with further reading, so please treat them as provisional!

73

Chris

G4DGU








Richard GD8EXI
 

One of the problems with dishes in windy locations is flutter (vibration in the wind). Standard sky dishes only last about two years here because of flutter induced metal fatigue. As G8DOH has already pointed out a solid dish has a high mechanical Q so is prone to flutter. I suspect mesh dishes have lower mechanical Qs so should do better. This is born out by GD4GNH’s experience with a 1.9m mesh dish at a very windy location.
 
To get back to the original question I suggest you park it in the direction, which leads to the least flutter as found experimentally.

We had a mean wind speed of 55Knots and gusting over 70Knots here yesterday so my largest Yagis were locked into wind.

Richard
GD8EXI



On 14/01/2020, 10:50, "Chris Bartram G4DGU" <chris@...> wrote:

> I've recently been working on the design of a new mast system and I want
> it to support a reasonable dish for terrestrial operation. A lattice
> tower wouldn't be appropriate here, and I need something a bit better
> than a beefed-up domestic installation. I also need easy access to the
> antennas. As I've never been particularly interested in 2.3, 3.4, and
> 5.6GHz, I plan to use a domestic 1 or 1.2m offset dish with an efficient
> dual-band 1.3/10GHz feed. A snake yagi would be unlikely to survive for
> very long here.
>
> Living in Cornwall where it's intrinsically windy, at a location which
> is also subject to katabatic winds falling off the range of hills on
> which the GB3MCB beacons sit, I've been looking at the problems from
> first principles. This seems to be an everyday problem on a par with
> circuit analysis for structural engineers ... My initial reading of a
> number of sources does seem to suggest that a worst case calculation of
> the force developed by the wind on a dish antenna is something which
> isn't that difficult to perform: the principles behind the building
> regulations take into account the aerodynamics of the dish in arriving
> at their figures.
>
> One very relevant point - which I have seen made in amateur radio
> publications, but which doesn't seem to be generally appreciated here -
> is that mesh dishes aren't that much better in terms of wind loading
> than than solid dishes of the same diameter at higher windspeeds. The
> difference seems to equate to a small penalty in dish diameter and the
> increased efficiency of the solid dish probably counteracts that.
>
> I hope these comments are useful: I'll probably understand this a lot
> better with further reading, so please treat them as provisional!
>
> 73
>
> Chris
>
> G4DGU
>
>
>
>


Chris Bartram G4DGU <chris@...>
 

John and Andy:

On mesh dishes, isn't it all about turbulence around the (thin) mesh conductive elements causing a much greater effective thickness?

I understand that something like that is the case. I have a feeling that turbulence effectively applies an exponential term to the area term of the equation relating wind speed to wind pressure. Hence streamlining!


But I don't even try to understand mechanical things, and just quoting summat I read yonks ago mixed with a gut feeling.

I'd normally run a mile from such mech. things! Bad memories of a wrong turn I once took in my 'education' ...


Richard:

I'd not seen any maths or comments on vibration fatigue of dishes, but a quick search does bring-up a couple of papers. I'll see if I can make sense of them later. The Sky dishes here do seem to suffer a bit more from corrosion, but given my location is only a few km the coast, that's unsurprising. My initial response to your comment would be to de-Q the dish. That could possibly be accomplished by the choice of a composite reflector eg. GRP or by use of some form of damping material on the rear of a thin metal dish. The design of the dish bracketry would probably have a significant effect on vibration modes. I'll do some digging ...


73 All.

Chris G4DGU


Conrad, PA5Y
 

A long time ago when I did my dissertation at Uni I read a JPL paper that described mesh versus solid dish windload results from experiments in a wind tunnel. It was for scaled down model of BIG dishes.  The conclusion was that the turbulence above 50 mph around mesh wires makes the wind load of a mesh dish close to that of a solid dish at wind speeds approaching or above this. I don't remember the exact wind speed at which they became the same but it was certainly in the range we would typically see on an average British hilltop. I could not find the original paper, there was a very telling accompanying graph, I will find it if I can find my dissertation. Most likely it is in the UK.

This is quite interesting:


73

Conrad PA5Y









From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of John Lemay via Groups.Io <john@...>
Sent: 14 January 2020 12:19
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Dishes and wind
 
Firstly, many thanks for the helpful comments yesterday. I went with my gut feeling, and pointed the dishes downwind, and all was well. There's more to come later today, probably worse than yesterday here if the forecast is correct.

My larger dish (2m diameter) is home designed and home built, so I have plenty of interest in its survival !

Chris -

I've read the same web pages as you have by the sound of it, regarding wind loading of mesh dishes v solid dishes. And I'm not convinced. But it occurs to me that we should be considering not two types of construction, but three types. These are solid, perforated material, and mesh. If we compare solid and perforated material I can understand that the difference in wind load is not great; I'm looking at a sample sheet of perforated aluminium and the holes probably represent 30% of the area. But with mesh (like RF HamDesign dishes) the gaps represent 70 to 90% of the area, depending on the mesh option chosen.

Nothing is simple, is it ?

Regards

John G4ZTR


-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Chris Bartram G4DGU
Sent: 14 January 2020 10:50
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

I've recently been working on the design of a new mast system and I want
it to support a reasonable dish for terrestrial operation. A lattice
tower wouldn't be appropriate here, and I need something a bit better
than a beefed-up domestic installation. I also need easy access to the
antennas. As I've never been particularly interested in 2.3, 3.4, and
5.6GHz, I plan to use a domestic 1 or 1.2m offset dish with an efficient
dual-band 1.3/10GHz feed. A snake yagi would be unlikely to survive for
very long here.

Living in Cornwall where it's intrinsically windy, at a location which
is also subject to katabatic winds falling off the range of hills on
which the GB3MCB beacons sit, I've been looking at the problems from
first principles. This seems to be an everyday problem on a par with
circuit analysis for structural engineers ... My initial reading of a
number of sources does seem to suggest that a worst case calculation of
the force developed by the wind on a dish antenna is something which
isn't that difficult to perform: the principles behind the building
regulations take into account the aerodynamics of the dish in arriving
at their figures.

One very relevant point - which I have seen made in amateur radio
publications, but which doesn't seem to be generally appreciated here -
is that mesh dishes aren't that much better in terms of wind loading
than than solid dishes of the same diameter at higher windspeeds. The
difference seems to equate to a small penalty in dish diameter and the
increased efficiency of the solid dish probably counteracts that.

I hope these comments are useful: I'll probably understand this a lot
better with further reading, so please treat them as provisional!

73

Chris

G4DGU








Keith
 

Living in the second windiest city on the planet after Chicago I park my dishes in the inverted umbrella position, feed pointing directly upwards.
Several years later and still no issues
Cheers 
Keith VK6KB / VK6EME Perth Western Australia.


Paul G8KFW
 

Hi Keith

 

I think that is how Parkes park theirs during high winds

 

Regards Paul


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Keith
Sent: 14 January 2020 14:44
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

 

Living in the second windiest city on the planet after Chicago I park my dishes in the inverted umbrella position, feed pointing directly upwards.
Several years later and still no issues
Cheers 
Keith VK6KB / VK6EME Perth Western Australia.

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.


--
Paul Bicknell G8KFW   South Coast UK


g4cch_1
 

My 5.4m EME dish is parked at almost 90deg elevation. The counterweight arms on the back of the dish are strapped to the tower to reduce the twisting motion on the azimuth shaft.

If wind is forecast for any length of time over 40mph, then I luff the dish over like this, and support/brace with scaffold tubes. The feed has to come off unfortunately to avoid rain getting in.


Tim, VK2XAX
 

Hi Paul,

All the VK dishes I know of park like that. But then we don't have issues with snow either. You can see some of the DSN dishes in Tidbinbilla parked here...

https://www.cdscc.nasa.gov/Images/Gallery/aerial4_fs.jpg

And for the Parkes dish in particular, a quote from....

https://www.csiro.au/en/Research/Facilities/ATNF/Parkes-radio-telescope/About-Parkes

"Because the large surface of the dish catches the wind like a sail, the telescope must be 'stowed' (pointed directly up) when the wind speed exceeds 35 kilometres an hour."

regards

Tim

On 15/01/2020 2:02 am, Paul G8KFW wrote:

Hi Keith

 

I think that is how Parkes park theirs during high winds

 

Regards Paul


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Keith
Sent: 14 January 2020 14:44
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

 

Living in the second windiest city on the planet after Chicago I park my dishes in the inverted umbrella position, feed pointing directly upwards.
Several years later and still no issues
Cheers 
Keith VK6KB / VK6EME Perth Western Australia.

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.


--
Paul Bicknell G8KFW   South Coast UK
-- 
VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA


Paul G8KFW
 

Hi Tim

 

The first picture you say from the gallery of aerial 4 but can you come back with the actual site

 

OK about the snow  that is how you achieved a first at 122 Ghz with reduced water vapour  at the moment in parts of the UK it is 100 % water

 

Regarding Parkes telescope and the film 'The Dish' I think there was a bit of licence  apparently the pictures coming from Parkes during Apollo 11 where better than the other station hence it was the major receiving station for Apollo 11 and gained extra work due to its better reception from space and is a credit to Australia the designers and those that built it

 

I think you will find the Parkes telescope has actually not always been stowed at winds above 35 kilometres an hour as during the Apollo 11 mission

 

any way best of luck with the samples for the 122 GHz project certainly cracked you first wish to go for 50 sets of equipment  nearly 10 times that now

 

Best Regards Paul


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Tim
Sent: 14 January 2020 23:56
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

 

Hi Paul,

All the VK dishes I know of park like that. But then we don't have issues with snow either. You can see some of the DSN dishes in Tidbinbilla parked here...

https://www.cdscc.nasa.gov/Images/Gallery/aerial4_fs.jpg

And for the Parkes dish in particular, a quote from....

https://www.csiro.au/en/Research/Facilities/ATNF/Parkes-radio-telescope/About-Parkes

"Because the large surface of the dish catches the wind like a sail, the telescope must be 'stowed' (pointed directly up) when the wind speed exceeds 35 kilometres an hour."

regards

Tim

On 15/01/2020 2:02 am, Paul G8KFW wrote:

Hi Keith

 

I think that is how Parkes park theirs during high winds

 

Regards Paul


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Keith
Sent: 14 January 2020 14:44
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

 

Living in the second windiest city on the planet after Chicago I park my dishes in the inverted umbrella position, feed pointing directly upwards.
Several years later and still no issues
Cheers 
Keith VK6KB / VK6EME Perth Western Australia.

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.


--
Paul Bicknell G8KFW   South Coast UK

-- 
VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.


--
Paul Bicknell G8KFW   South Coast UK


Paul Randall G3NJV
 

The original 1960’s Telstar 85ft antenna (Goonhilly 1) stowed on the horizon with “back to wind”. On the other hand, the 32 meter KU band Mitsubishi Goonhilly 5 stowed at zenith - which turned out to be the most common position for all the big antenna. Some small cheap <15m antenna did not have full motion so could not be stowed.

Although 100 mph wind gusts were common on the extremely exposed Goonhilly Downs site on the Lizard peninsular in Cornwall, no dish was ever taken from service and stowed. However, it was interesting to watch the active tracking equipment trying to keep pointing errors to a minimum whilst the control building shook in the wind. A lot of the “tracking error” that was being corrected was of course caused by flexing of the steel structures.

 

I recall one major “off track” event on Goonhilly 2 (now scrapped) that was later attributed to one of the railway-track type “bogies” lifting clear from its track under wind pressure.

 

My brother managed to slightly bend a steel girder on Goonhilly 1 by trying to move it with the stow lock still engaged. This original dish was based on a naval gun turret, designed by Husband & Co to track the first LEO comsat; it had to spin really fast in azimuth on near overhead passes! It had Ward-Leonard steering motors, something like 750HP. To put this in perspective, the later and larger 1970s Marconi Goonhilly 3 antenna had just 2HP steering motors with 20HP slew motors for fast repositioning.

 

Happy Daiz

Paul G3NJV

 

Sent from Mail for Windows 10

 


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Tim <VK2XAX@...>
Sent: Tuesday, January 14, 2020 11:56:04 PM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Dishes and wind
 

Hi Paul,

All the VK dishes I know of park like that. But then we don't have issues with snow either. You can see some of the DSN dishes in Tidbinbilla parked here...

https://www.cdscc.nasa.gov/Images/Gallery/aerial4_fs.jpg

And for the Parkes dish in particular, a quote from....

https://www.csiro.au/en/Research/Facilities/ATNF/Parkes-radio-telescope/About-Parkes

"Because the large surface of the dish catches the wind like a sail, the telescope must be 'stowed' (pointed directly up) when the wind speed exceeds 35 kilometres an hour."

regards

Tim

On 15/01/2020 2:02 am, Paul G8KFW wrote:

Hi Keith

 

I think that is how Parkes park theirs during high winds

 

Regards Paul


From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Keith
Sent: 14 January 2020 14:44
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Dishes and wind

 

Living in the second windiest city on the planet after Chicago I park my dishes in the inverted umbrella position, feed pointing directly upwards.
Several years later and still no issues
Cheers 
Keith VK6KB / VK6EME Perth Western Australia.

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.8048 / Virus Database: 4793/15886 - Release Date: 08/14/18
Internal Virus Database is out of date.


--
Paul Bicknell G8KFW   South Coast UK
-- 
VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA


alwyn.seeds1
 

The same Husband & Co. that did the structural design for Jodrell Bank.

Interesting description of the issues faced in Lovell’s book “The Story of Jodrell Bank”.

Regards,

Alwyn
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Alan Beard
 

Taken on Ponape, Federated States of Melanesia 

What happens if the wind blows the wrong way???

Taken in 2010

Alan VK2ZIW

On Wed, 15 Jan 2020 10:24:03 +0000, alwyn.seeds1 wrote
> The same Husband & Co. that did the structural design for Jodrell Bank.
>

> Interesting description of the issues faced in [UTF-8?]Lovell’s book [UTF-8?]“The Story of Jodrell [UTF-8?]Bank�.
>

> Regards,
>

> Alwyn

>
> _____________________________________________________
>

> Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
> _____________________________________________________


---------------------------------------------------
Alan Beard

OpenWebMail 2.53


Pete - GM4BYF
 

If the wind blows the wrong way, this is what happens !!

Fortunately no damage to anybody or anything - except my pride!

See attached

73
Pete GM4BYF
On 16/01/20 10:00, Alan Beard wrote:

Taken on Ponape, Federated States of Melanesia 

What happens if the wind blows the wrong way???

Taken in 2010

Alan VK2ZIW

On Wed, 15 Jan 2020 10:24:03 +0000, alwyn.seeds1 wrote
> The same Husband & Co. that did the structural design for Jodrell Bank.
>

> Interesting description of the issues faced in [UTF-8?]Lovell’s book [UTF-8?]“The Story of Jodrell [UTF-8?]Bank�.
>

> Regards,
>

> Alwyn

>
> _____________________________________________________
>

> Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
> _____________________________________________________


---------------------------------------------------
Alan Beard

OpenWebMail 2.53


--
vry 73
Pete GM4BYF


Paul Randall G3NJV
 

I think that picture shows the elevation actuator has been removed.
Paul


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Alan Beard <beardal@...>
Sent: 16 January 2020 10:00
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Dishes and wind
 
Taken on Ponape, Federated States of Melanesia 

What happens if the wind blows the wrong way???

Taken in 2010

Alan VK2ZIW

On Wed, 15 Jan 2020 10:24:03 +0000, alwyn.seeds1 wrote
> The same Husband & Co. that did the structural design for Jodrell Bank.
>

> Interesting description of the issues faced in [UTF-8?]Lovell’s book [UTF-8?]“The Story of Jodrell [UTF-8?]Bank�.
>

> Regards,
>

> Alwyn

>
> _____________________________________________________
>

> Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
> _____________________________________________________


---------------------------------------------------
Alan Beard

OpenWebMail 2.53