Diy Freesat

[rbel]

I have decided to try a diy Freesat installation and the first
question is, would a 54/60 cms dish mounted at right angles to a 5
metre long wall, pointing 28.2 degrees east of south and correctly
elevated, run into reception problems because its path is too close to
the wall? The wall is higher than the top of the dish.

Iffy ASCII plan view

dish
)
28.2 degrees Lnb < )
___________________________________________)__
5 metre long exterior wall
I take it that the relatively close proximity of tree foliage behind
the dish will not cause problems provided that it does not touch the
dish under any circumstances. The property is on the south coast so I
assume that a zone 2 dish will be more than adequate.
--
rbel

[rbel]

On Thu, 16 May 2013 19:15:47 +0100, rbel wrote:

>
>I have decided to try a diy Freesat installation and the first
>question is, would a 54/60 cms dish mounted at right angles to a 5
>metre long wall, pointing 28.2 degrees east of south and correctly
>elevated, run into reception problems because its path is too close to
>the wall? The wall is higher than the top of the dish.
>

>I take it that the relatively close proximity of tree foliage behind
>the dish will not cause problems provided that it does not touch the
>dish under any circumstances. The property is on the south coast so I
>assume that a zone 2 dish will be more than adequate.

Try again with the plan view

dish
> )
>28.2 degrees Lnb < )
>___________________________________________)__
> 5 metre long exterior wall

--
rbel

[rbel]

On Thu, 16 May 2013 20:08:43 +0100, rbel wrote:

>On Thu, 16 May 2013 19:15:47 +0100, rbel wrote:
>
>>
>>I have decided to try a diy Freesat installation and the first
>>question is, would a 54/60 cms dish mounted at right angles to a 5
>>metre long wall, pointing 28.2 degrees east of south and correctly
>>elevated, run into reception problems because its path is too close to
>>the wall? The wall is higher than the top of the dish.
>>
>
>>I take it that the relatively close proximity of tree foliage behind
>>the dish will not cause problems provided that it does not touch the
>>dish under any circumstances. The property is on the south coast so I
>>assume that a zone 2 dish will be more than adequate.
>
>Try again with the plan view

>> )
>>28.2 degrees Lnb < )
>>___________________________________________)__
>> 5 metre long exterior wall

The dish is supposed to be represented by the vertical column of ) at
the right side of the diagram - pointing to the left side.
--
rbel

[Phil Wieland]

The satellite is at 28.2 longitude, that is NOT the bearing from your
location.

--
Phil
Liverpool, UK

[rbel]

On Thu, 16 May 2013 20:42:12 +0100, Phil Wieland <ph...@nospam.ta>
wrote:

Apologies - should have said pointing 'to' 28.2 degrees east of south.
--
rbel

[MikeS]

<rbel> wrote in message news:d08ap8pse139rhn1s...@4ax.com...

Try using this:
http://www.dishpointer.com/
It will show you on a map or satellite image exactly where your dish should
point.

[rbel]

On Thu, 16 May 2013 21:08:25 +0100, "MikeS" <mis...@gothere.ukX.com>
wrote:

A useful tool - many thanks. It confirms my thoughts that the dish
would need to be at right angles to the wall. If the dish is 60 cms
diameter does it need only a 60 cms wide field of view towards the
satellite, in other words will the adjacent wall interfere with the
signal?
--
rbel

[Woody]

<rbel> wrote in message
news:utfap89f7o89338n1...@4ax.com...

Why not put it at the other end of the wall and run a longer
cable, or am I missing something?


--
Woody

harrogate three at ntlworld dot com

[rbel]

On Thu, 16 May 2013 22:51:42 +0100, "Woody" <harro...@ntlworld.com>

wrote:

><rbel> wrote in message
>news:utfap89f7o89338n1...@4ax.com...
>> On Thu, 16 May 2013 21:08:25 +0100, "MikeS"
>> <mis...@gothere.ukX.com>
>> wrote:
>>
>>><rbel> wrote in message
>>>news:d08ap8pse139rhn1s...@4ax.com...
>>>>
>>>> I have decided to try a diy Freesat installation and the
>>>> first
>>>> question is, would a 54/60 cms dish mounted at right angles
>>>> to a 5
>>>> metre long wall, pointing 28.2 degrees east of south and
>>>> correctly
>>>> elevated, run into reception problems because its path is too
>>>> close to
>>>> the wall? The wall is higher than the top of the dish.

>>>

>>>Try using this:
>>> http://www.dishpointer.com/
>>>It will show you on a map or satellite image exactly where your
>>>dish should
>>>point.
>>>
>> A useful tool - many thanks. It confirms my thoughts that the
>> dish
>> would need to be at right angles to the wall. If the dish is
>> 60 cms
>> diameter does it need only a 60 cms wide field of view towards
>> the
>> satellite, in other words will the adjacent wall interfere with
>> the
>> signal?

>

>Why not put it at the other end of the wall and run a longer
>cable, or am I missing something?

It would stick out like a sore thumb - please see my previous thread
'Flat panel satellite dish' of 11/12 May.
--
rbel

[Brian Gaff]

Which makes me think, is there any audio alignment device available for
dishes. Ie the tone pitch rises as the signal does that way, once in the
right basic positionn, it could be fine tuned with very little gear and with
crap eyesight.. grin.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Woody" <harro...@ntlworld.com> wrote in message
news:kn3k65$5k2$1...@dont-email.me...

[Steve Thackery]

Brian Gaff wrote:

> Which makes me think, is there any audio alignment device available
> for dishes. Ie the tone pitch rises as the signal does that way,
> once in the right basic positionn, it could be fine tuned with very
> little gear and with crap eyesight.. grin.

Yes, that's how those cheap boxes you can get from B&Q work. The tone
volume changes, rather than the pitch. I've set up three dishes using
one. They are surprisingly sensitive if you are patient enough - just
the lightest pressure on the rim of the dish makes an audible
difference.

Obviously they don't know about the bit error rate, but I followed
Bill's advice and rotated the LNB until the cables came out at about
7o'clock, and this got me a good "signal quality" reading on the
satellite PVRs.

--
SteveT

[David Woolley]

rbel wrote:

>>> dish
>>> )
>>> 28.2 degrees Lnb < )
>>> ___________________________________________)__
>>> 5 metre long exterior wall

Doesn't work with a monospace font!

> A useful tool - many thanks. It confirms my thoughts that the dish
> would need to be at right angles to the wall. If the dish is 60 cms
> diameter does it need only a 60 cms wide field of view towards the
> satellite, in other words will the adjacent wall interfere with the
> signal?

Most dishes have offset feeds so the optical near field (< Rayleigh
distance) is elliptical.

Ideally, you don't want anything hotter than about minus 200 degrees C
(not sure what typical LNB noise temperatures are) within the beam
aperture, allowing for some divergence of the beam. However, LNBs are
designed to pick up very little from the edge of the dish, so they pick
up even less from its surroundings, so the actual aperture to consider
may be smaller than it at first looks.

Unfortunately, most of the theoretical stuff is for situations where the
signal or noise source is lot further away than the Rayleigh distance
(the point at which the beam tends to be conical, rather than
cylindrical, so, I'm not sure how far outside the aperture ellipse you
need to be for noise pickup to be negligible.

Also, an object that is outside of the beam can still diffract signals
towards or away from the dish, although, given the large aperture of the
dish in wavelengths, I suspect this is not nearly as significant as for
DTT aerials.

[rbel]

On Fri, 17 May 2013 09:29:21 +0200, Martin <m...@address.invalid> wrote:

>>>>>> I have decided to try a diy Freesat installation and the
>>>>>> first
>>>>>> question is, would a 54/60 cms dish mounted at right angles
>>>>>> to a 5
>>>>>> metre long wall, pointing 28.2 degrees east of south and
>>>>>> correctly
>>>>>> elevated, run into reception problems because its path is too
>>>>>> close to
>>>>>> the wall? The wall is higher than the top of the dish.
>>

>

>I went down this path last summer. The installer didn't have a fitting
>that allowed the dish to be installed at 90 degrees to the wall. I
>gave up and have the dish attached to the front of the house.
>
>You might find this useful. http://www.astra2.org/dish.html

It is - many thanks
--
rbel

[R. Mark Clayton]

<rbel> wrote in message news:d08ap8pse139rhn1s...@4ax.com...
>

How sure are you about the angle of the wall?

The further east and to a lesser extent south) you are in the UK the more
likely this is to work. Try and mount the dish as far away from the wall as
practicable, bearing in mind that this will increase the leverage of the
wind load on the mount. Also mount high on the wall. If you use a 60cm
dish then a little shading on one side will probably not cause that much
difficulty.

[alan]

On 17/05/2013 08:14, Brian Gaff wrote:
> Which makes me think, is there any audio alignment device available for
> dishes. Ie the tone pitch rises as the signal does that way, once in the
> right basic positionn, it could be fine tuned with very little gear and with
> crap eyesight.. grin.
>

�6 or �7 from ebay
<http://www.ebay.co.uk/itm/Amiko-Satellite-Signal-Meter-Finder-for-Sky-Freesat-more-2-Year-Guarantee-/150981791675?pt=UK_Sound_Vision_Other&hash=item2327374fbb>

and how to use (including video)
http://www.satcure.co.uk/tech/satmeter.htm

--
mailto:news{at}admac(dot}myzen{dot}co{dot}uk

[rbel]

On Fri, 17 May 2013 13:37:19 +0100, "R. Mark Clayton"
<nospam...@btinternet.com> wrote:

>
><rbel> wrote in message news:d08ap8pse139rhn1s...@4ax.com...
>>
>> I have decided to try a diy Freesat installation and the first
>> question is, would a 54/60 cms dish mounted at right angles to a 5
>> metre long wall, pointing 28.2 degrees east of south and correctly
>> elevated, run into reception problems because its path is too close to
>> the wall? The wall is higher than the top of the dish.
>>
>> Iffy ASCII plan view
>>
>> dish
>> )
>> 28.2 degrees Lnb < )
>> ___________________________________________)__
>> 5 metre long exterior wall
>> I take it that the relatively close proximity of tree foliage behind
>> the dish will not cause problems provided that it does not touch the
>> dish under any circumstances. The property is on the south coast so I
>> assume that a zone 2 dish will be more than adequate.
>> --
>> rbel
>
>How sure are you about the angle of the wall?

I think I have got this right. I placed the straight edge of a decent
Silva map reading compass against the wall in a couple of places, set
the dial to north and read off the bearing which was 148 degrees. As
this is 32 degrees east of south I assume that would give me, in
theory, approximately 4 degrees of leeway. The dishpointer.com site
suggested by MikeS gives an indication that this not far off.

>The further east and to a lesser extent south) you are in the UK the more
>likely this is to work. Try and mount the dish as far away from the wall as
>practicable, bearing in mind that this will increase the leverage of the
>wind load on the mount. Also mount high on the wall. If you use a 60cm
>dish then a little shading on one side will probably not cause that much
>difficulty.
>

The dish could be mounted at a centre height of 3.4 metres above
ground level with a hedge maintained at 3 metres tall about 12 metres
away in the direction of the satellite.

As we are subject to very high winds here (on top of a hill near the
South Devon coast) I would want to mount the dish as close as possible
to wall.

Using a 54 cms dish would reduce the windage by around 20% and I
imagine that it would not have a significant impact on the signal
reception.
--
rbel

[Woody]

<rbel> wrote in message
news:66ocp8p2m5rehupir...@4ax.com...

This is a very good site - developed I think by one of the
contributors to this NG. It will show you an OS map line for the
dish and a Google maps satellite view. You can move the end of
the line to exactly where you want it on your house.

http://www.macfh.co.uk/JavaJive/AudioVisualTV/SatelliteTV/SatelliteCalculator.php

[Jim]

At a random location in Plymouth, Dishpointer gives an
azimuth reading for the satellites at 28.2E of
140.6� true
143.2� magnetic
which would put them behind the wall at 148� magnetic.

I had an installation similar to this at my last
house, with the dish perpendicular to the wall. The
biggest problem was finding a bracket that would let
me mount it this way. Luckily, my neighbour had a
spare cranked mast in his garage.

54cm dish size should be plenty at your location, but
a smaller one might be easier to install. In your
case, the dish would need to be mounted at least
half-a-metre off the wall (by my simple - but not
necessarily correct - trig calculation) in order to
get the azimuth clear. I don't know what effect, if
any, wall reflections or refractions would have on the
signal.

[alan]

On 17/05/2013 18:39, rbel wrote:

>

> I think I have got this right. I placed the straight edge of a decent
> Silva map reading compass against the wall in a couple of places, set
> the dial to north and read off the bearing which was 148 degrees. As
> this is 32 degrees east of south I assume that would give me, in
> theory, approximately 4 degrees of leeway. The dishpointer.com site
> suggested by MikeS gives an indication that this not far off.

In case you are not aware, you can drag the end of the green line to the
satellite to the intended position of your dish and then zoom in on the
map or satellite photo.

[rbel]

On Sat, 18 May 2013 05:30:42 +0100, alan <ju...@admac.myzen.co.uk>
wrote:

I had done this using dishpointer and JavaJive's app and the line is
at best parallel to the wall and worst fractionally the wrong side of
it.

Given this and the advice that the dish would need to stand off the
wall by more than I would wish, leads me to think that I should
endeavour to find another location for it, which is not easy. I may
end up needing to use the flat panel Selfsat H30D2 antenna mentioned
in a previous thread, on a more exposed SSE facing wall.

Many thanks for the advice.
--
rbel

[Bill Wright]

You can put the dish on a table or chair directly below the place where
you'd like to mount it and align it by hand for the satellite. Then it
will be obvious if it's fractionally looking 'towards' or 'away' from
the wall by checking the angle of the LNB arm relative to the wall. If
it's borderline (arm appears parallel to wall) prop the dish up (as
above) and see if the signal level drops when you obstruct the surface
of the dish near the edge that's closest to the wall. If the signal
doesn't drop the wall or guttering is partly obstructing the signal. By
this method you can find the distance from the wall you would need to
mount the dish so all parts of its surface can 'see' the satellite. This
is how an installer would do it: testing the signal before starting to
drill holes in the wall.
If there's a problem could you mount the dish just above gutter height?

Bill

[R. Mark Clayton]

<rbel> wrote in message news:66ocp8p2m5rehupir...@4ax.com...

> On Fri, 17 May 2013 13:37:19 +0100, "R. Mark Clayton"
> <nospam...@btinternet.com> wrote:
>
>>
>>
>>How sure are you about the angle of the wall?
>
> I think I have got this right. I placed the straight edge of a decent
> Silva map reading compass against the wall in a couple of places, set
> the dial to north and read off the bearing which was 148 degrees. As
> this is 32 degrees east of south I assume that would give me, in
> theory, approximately 4 degrees of leeway. The dishpointer.com site
> suggested by MikeS gives an indication that this not far off.
>

A magnetic compass - about 7 degrees out IIRC. You need to find the
correction where you are from a RECENT OS map.

>
>>The further east and to a lesser extent south) you are in the UK the more
>>likely this is to work. Try and mount the dish as far away from the wall
>>as
>>practicable, bearing in mind that this will increase the leverage of the
>>wind load on the mount. Also mount high on the wall. If you use a 60cm
>>dish then a little shading on one side will probably not cause that much
>>difficulty.
>>
>
> The dish could be mounted at a centre height of 3.4 metres above
> ground level with a hedge maintained at 3 metres tall about 12 metres
> away in the direction of the satellite.

The hedge will not be a problem,

>
> As we are subject to very high winds here (on top of a hill near the
> South Devon coast) I would want to mount the dish as close as possible
> to wall.

Then you are about 4 degrees west of Greenwich - this is going to make this
harder.

>
> Using a 54 cms dish would reduce the windage by around 20% and I
> imagine that it would not have a significant impact on the signal
> reception.

Try it and see, as you are further south this reduces the size of dish
required.

> --
> rbel

[R. Mark Clayton]

"Bill Wright" <bi...@invalid.com> wrote in message
news:kn8hha$mgm$1...@speranza.aioe.org...

Not very scientific Bill. Science works better though - I correctly aligned
my 1.2m steerable Gregorian dish [first time] by calcualation and
observation and without a sat meter.

[Java Jive]

Or from my calculator which has an up-to-date version of the World
Magnetic Model software running in it ...

On Sun, 19 May 2013 14:21:05 +0100, "R. Mark Clayton"
<nospam...@btinternet.com> wrote:
>
> A magnetic compass - about 7 degrees out IIRC. You need to find the
> correction where you are from a RECENT OS map.

--
=========================================================
Please always reply to ng as the email in this post's
header does not exist. Or use a contact address at:
http://www.macfh.co.uk/JavaJive/JavaJive.html
http://www.macfh.co.uk/Macfarlane/Macfarlane.html

[Woody]

"R. Mark Clayton" <nospam...@btinternet.com> wrote in message
news:haednbPbVKgmTAXM...@bt.com...

>
> <rbel> wrote in message
> news:66ocp8p2m5rehupir...@4ax.com...
>> On Fri, 17 May 2013 13:37:19 +0100, "R. Mark Clayton"
>> <nospam...@btinternet.com> wrote:
>>
>>>
>>>
>>>How sure are you about the angle of the wall?
>>
>> I think I have got this right. I placed the straight edge of a
>> decent
>> Silva map reading compass against the wall in a couple of
>> places, set
>> the dial to north and read off the bearing which was 148
>> degrees. As
>> this is 32 degrees east of south I assume that would give me,
>> in
>> theory, approximately 4 degrees of leeway. The
>> dishpointer.com site
>> suggested by MikeS gives an indication that this not far off.
>>
>
> A magnetic compass - about 7 degrees out IIRC. You need to
> find the correction where you are from a RECENT OS map.

[snip]

Have a look at JJ's calculator (link an another posting) for an
exact figure but I think current magnetic offset is about 3degW.


--
Woody

harrogate three at ntlworld dot com

[rbel]

On Sun, 19 May 2013 14:34:47 +0100, Java Jive <ja...@evij.com.invalid>
wrote:

>Or from my calculator which has an up-to-date version of the World
>Magnetic Model software running in it ...
>
>On Sun, 19 May 2013 14:21:05 +0100, "R. Mark Clayton"
><nospam...@btinternet.com> wrote:
>>
>> A magnetic compass - about 7 degrees out IIRC. You need to find the
>> correction where you are from a RECENT OS map.

It was using your calculator with the magnetic compensation adjustment
that persuaded me that the 'dish at a right angle to wall' position
was so borderline that I should look for an alternative location.

Having spent some time wandering around this weekend it looks as
though a corner of the rear lawn is the best compromise position. I
can run some conduit under the lawn and adjacent paved area to take
the twin WF100 cable. I have a found 'transparent' 60 cms dish which
should, in theory, meld reasonably with the hedging background -
http://www.primesat.eu/transparent_satellite_dish60cm.php
--
rbel

[Bill Wright]

R. Mark Clayton wrote:

>> You can put the dish on a table or chair directly below the place where
>> you'd like to mount it and align it by hand for the satellite. Then it
>> will be obvious if it's fractionally looking 'towards' or 'away' from the
>> wall by checking the angle of the LNB arm relative to the wall. If it's
>> borderline (arm appears parallel to wall) prop the dish up (as above) and
>> see if the signal level drops when you obstruct the surface of the dish
>> near the edge that's closest to the wall. If the signal doesn't drop the
>> wall or guttering is partly obstructing the signal. By this method you can
>> find the distance from the wall you would need to mount the dish so all
>> parts of its surface can 'see' the satellite. This is how an installer
>> would do it: testing the signal before starting to drill holes in the
>> wall.
>> If there's a problem could you mount the dish just above gutter height?
>>
>> Bill
>
> Not very scientific Bill.

He isn't trying to get a PhD, he's trying to line up a fucking satellite
dish.
Anyway, I thought good scientific method included trying everything
until you find something that works. That's what the drug companies do.

Science works better though - I correctly aligned
> my 1.2m steerable Gregorian dish [first time] by calcualation and
> observation and without a sat meter.

And I would have done it in two minutes using my meter, and afterwards
my head wouldn't have hurt.

Bill

[Ian]

In message <b8jip85mu1693bvi4...@4ax.com>, Martin
<m...@address.invalid> writes
>On Sun, 19 May 2013 20:50:51 +0100, Bill Wright <bi...@invalid.com>
>wrote:

>
>>R. Mark Clayton wrote:
>>
>>>> You can put the dish on a table or chair directly below the place where
>>>> you'd like to mount it and align it by hand for the satellite. Then it
>>>> will be obvious if it's fractionally looking 'towards' or 'away' from the
>>>> wall by checking the angle of the LNB arm relative to the wall. If it's
>>>> borderline (arm appears parallel to wall) prop the dish up (as above) and
>>>> see if the signal level drops when you obstruct the surface of the dish
>>>> near the edge that's closest to the wall. If the signal doesn't drop the
>>>> wall or guttering is partly obstructing the signal. By this method you can
>>>> find the distance from the wall you would need to mount the dish so all
>>>> parts of its surface can 'see' the satellite. This is how an installer
>>>> would do it: testing the signal before starting to drill holes in the
>>>> wall.
>>>> If there's a problem could you mount the dish just above gutter height?
>>>>
>>>> Bill
>>>
>>> Not very scientific Bill.
>>He isn't trying to get a PhD, he's trying to line up a fucking satellite
>>dish.
>>Anyway, I thought good scientific method included trying everything
>>until you find something that works. That's what the drug companies do.
>

>and the Hull suicide who tried several different methods before
>killing himself with cyanide ordered via internet from the USA
>
>"Shortly after his mum's death, he tried to gas himself but failed.
>
>He later tried to hang himself but the ligature snapped. He also
>overdosed on a couple of occasions.
>
>He tried to take his life once more in a hotel room by dousing sheets
>in a nicotine solution but this failed.
>
>He even attempted water intoxication by drinking several litres of
>water but, again, the attempt failed. "

I wonder if he wanted to die because his life consisted of one failure
after another.
--
Ian

[rbel]

On Mon, 20 May 2013 00:06:38 +0200, Martin <m...@address.invalid> wrote:

>Won't the pole shake when there is a gale blowing?

I would not have thought so - a 50mm pole with the bottom end in a 50
cms hole filled with concrete and the dish mounted around 1 metre
above ground level. I am not going to use the tripod setup indicated
in the primesat images.
--
rbel

[Bill Wright]

rbel wrote:

>> Won't the pole shake when there is a gale blowing?
>
> I would not have thought so - a 50mm pole with the bottom end in a 50
> cms hole filled with concrete and the dish mounted around 1 metre
> above ground level. I am not going to use the tripod setup indicated
> in the primesat images.

There's no problem at all with a 2" scaffold tube set in a decent amount
of concrete (65cm dish at ground level).

Scaffold firms often give away short lengths of steel tube.

Bill

[rbel]

On Mon, 20 May 2013 11:03:06 +0200, Martin <m...@address.invalid> wrote:

>>>>
>>>>Having spent some time wandering around this weekend it looks as
>>>>though a corner of the rear lawn is the best compromise position. I
>>>>can run some conduit under the lawn and adjacent paved area to take
>>>>the twin WF100 cable. I have a found 'transparent' 60 cms dish which
>>>>should, in theory, meld reasonably with the hedging background -
>>>>http://www.primesat.eu/transparent_satellite_dish60cm.php
>>>
>>>Won't the pole shake when there is a gale blowing?
>>
>>I would not have thought so - a 50mm pole with the bottom end in a 50
>>cms hole filled with concrete and the dish mounted around 1 metre
>>above ground level. I am not going to use the tripod setup indicated
>>in the primesat images.
>

>You didn't mention that you were going to mount it one metre above the
>ground.

I apologise
--
rbel

[Bill Wright]

Martin wrote:

> You didn't mention that you were going to mount it one metre above the
> ground.

No you didn't. I'd say it would probably be OK, but it sounds a little
bit iffy to me.

Bill