Satellite Dish Bearing

[Jeff Gaines]

I am trying to see if I could have a satellite dish to serve my Freesat
box. As far as I can see from Googling I need to allow 5 degrees variation
so point it at 247 degrees. Does this seem correct for Alderholt (3 mile
west of Fordingbridge, Hampshire)? At this stage I'm just trying to see if
it's feasible with trees/obstacle etc.

Will an aerial installer be able to fit me a wideband Sky dish without
signing me up to Sky?


--
Jeff Gaines Dorset UK
If you ever find something you like buy a lifetime supply because they
will stop making it

[Indy Jess John]

On 15/04/2022 09:51, Jeff Gaines wrote:
>
> I am trying to see if I could have a satellite dish to serve my Freesat
> box. As far as I can see from Googling I need to allow 5 degrees variation
> so point it at 247 degrees. Does this seem correct for Alderholt (3 mile
> west of Fordingbridge, Hampshire)? At this stage I'm just trying to see if
> it's feasible with trees/obstacle etc.
>
> Will an aerial installer be able to fit me a wideband Sky dish without
> signing me up to Sky?
>
>

If you have neighbours with a satellite dish, see where that is
pointing, and if possible use a gadget of some kind to mark the angle or
use a compass to identify the direction it is pointing to. Then go back
to your house and see what might be in the way if you fit a dish.

I did that using a neighbour's Sky dish and then managed to find a place
on my own house where there was a clear line to the satellite between a
chimney stack on one side and a tree on the other. When I put my dish
up (aided by a satellite signal meter), it worked perfectly.

Jim

[Andy Burns]

Jeff Gaines wrote:

> I am trying to see if I could have a satellite dish to serve my Freesat box. As
> far as I can see from Googling I need to allow 5 degrees variation

5° seems a lot.

> so point it at 247 degrees. Does this seem correct for Alderholt (3 mile west
> of Fordingbridge, Hampshire)

Dishpointer says 143.3°

[charles]

In article <xn0ngn6up...@news.individual.net>, Jeff Gaines

<jgaines...@yahoo.co.uk> wrote:

> I am trying to see if I could have a satellite dish to serve my Freesat
> box. As far as I can see from Googling I need to allow 5 degrees
> variation so point it at 247 degrees.

Conventionally, 270° is due West; that's not where the Freesat beast lives.

> Does this seem correct for
> Alderholt (3 mile west of Fordingbridge, Hampshire)? At this stage I'm
> just trying to see if it's feasible with trees/obstacle etc.

In Surrey, I reckon my dish is pointing at about 150°; it won't be very
different in Hampshire

> Will an aerial installer be able to fit me a wideband Sky dish without
> signing me up to Sky?

Why do you want a Sky dish if you want Freesat?

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

[charles]

In article <jbst5p...@mid.individual.net>, Andy Burns

so my 'about 150°' was reasonably correct

[Jeff Gaines]

On 15/04/2022 in message <xn0ngn6up...@news.individual.net> Jeff

Gaines wrote:

>
>I am trying to see if I could have a satellite dish to serve my Freesat
>box. As far as I can see from Googling I need to allow 5 degrees variation
>so point it at 247 degrees. Does this seem correct for Alderholt (3 mile
>west of Fordingbridge, Hampshire)? At this stage I'm just trying to see if
>it's feasible with trees/obstacle etc.
>
>Will an aerial installer be able to fit me a wideband Sky dish without
>signing me up to Sky?

Thanks for the replies :-)

I screwed the maths up, I think the answer is 153 degrees (including an
allowance of 5 for variation) as follows:

180 - 23 - 5 = 153.

I think I took the variation off twice then wrote 247 instead of 147, good
job I'm not flying to the moon!

I found:

"The most common satellites in the UK are the Astra 2 satellites at 28.2E
and Eurobird at 28.5E."

However, that's meaningless to me, the compass starts at 0 and ends at 359
or 360 depending how pedantic you want to be.

I suggested a Sky dish as with the wideband (Sky Q) version I can record 4
channels (from memory) at a time. Doesn't happen very often that there's 4
channels worth recording but does occasionally and as I'm starting from
scratch I might as well do it properly. If there's a non Sky version that
will do fine.

There's only one neighbour with a dish, it's mounted on an extension roof
and points at the house roof so may not be too effective. There is a large
tree which I think may be in the way which is why I want to get a rough
idea before calling an installer in.

Thanks again.

--
Jeff Gaines Dorset UK

There are 3 types of people in this world. Those who can count, and those
who can't.

[charles]

In article <xn0ngn9gx...@news.individual.net>, Jeff Gaines

The dish won't record anything. You need a suitable recording device. If
you want a Sky device, then you will need a subscription.

> There's only one neighbour with a dish, it's mounted on an extension roof
> and points at the house roof so may not be too effective.

It probably looks over the house roof. Dishes, in general, either work - or
they don't.

> There is a large tree which I think may be in the way which is why I want
> to get a rough idea before calling an installer in.

> Thanks again.

--

[williamwright]

On 15/04/2022 09:51, Jeff Gaines wrote:
>

> I am trying to see if I could have a satellite dish to serve my Freesat
> box. As far as I can see from Googling I need to allow 5 degrees
> variation so point it at 247 degrees. Does this seem correct for
> Alderholt (3 mile west of Fordingbridge, Hampshire)? At this stage I'm
> just trying to see if it's feasible with trees/obstacle etc.
>
> Will an aerial installer be able to fit me a wideband Sky dish without
> signing me up to Sky?
>
>

Stand at the proposed dish location and face due south, then divert your
gaze about 28deg to the east of due south. That's the direction you need
for Sky/Freesat.

You can use a Sky dish or a non-Sky dish, but you don't want a wideband
LNB. You just need an ordinary LNB with four outputs. Two are spare and
you run two cables from the others to your freesat box. Then you can
record as many channels as you want, depending on the box's capabilities.

Bill

[Andy Burns]

charles wrote:

> In article <xn0ngn9gx...@news.individual.net>, Jeff Gaines
> <jgaines...@yahoo.co.uk> wrote:
>> On 15/04/2022 in message <xn0ngn6up...@news.individual.net> Jeff
>> Gaines wrote:
>
>>>
>>> I am trying to see if I could have a satellite dish to serve my Freesat
>>> box. As far as I can see from Googling I need to allow 5 degrees
>>> variation so point it at 247 degrees. Does this seem correct for
>>> Alderholt (3 mile west of Fordingbridge, Hampshire)? At this stage I'm
>>> just trying to see if it's feasible with trees/obstacle etc.
>>>
>>> Will an aerial installer be able to fit me a wideband Sky dish without
>>> signing me up to Sky?
>
>> Thanks for the replies :-)
>
>> I screwed the maths up, I think the answer is 153 degrees (including an
>> allowance of 5 for variation) as follows:
>
>> 180 - 23 - 5 = 153.

The 23 should be the 28.2 still not sure where the 5 comes from, but it works
out about the same number

>> I think I took the variation off twice then wrote 247 instead of 147,
>> good job I'm not flying to the moon!
>
>> I found:
>
>> "The most common satellites in the UK are the Astra 2 satellites at 28.2E
>> and Eurobird at 28.5E."

Eurobird is long gone

>> However, that's meaningless to me, the compass starts at 0 and ends at
>> 359 or 360 depending how pedantic you want to be.
>
>> I suggested a Sky dish as with the wideband (Sky Q) version I can record
>> 4 channels (from memory) at a time. Doesn't happen very often that
>> there's 4 channels worth recording but does occasionally and as I'm
>> starting from scratch I might as well do it properly. If there's a non
>> Sky version that will do fine.

if you want non-sky, you could get a wideband LNB fitted (probably would say get
one with combined universal and wideband while at it) the one of the newest
freesat boxes, e.g.

<https://www.argos.co.uk/product/2075868>

> The dish won't record anything. You need a suitable recording device. If
> you want a Sky device, then you will need a subscription.

well you can buy a non-Q sky box second hand, those weren't rented like the Q
boxes are.

[Andy Burns]

williamwright wrote:

> you don't want a wideband LNB. You just need an ordinary LNB with four outputs.
> Two are spare and you run two cables from the others to your freesat box. Then
> you can record as many channels as you want, depending on the box's capabilities.

He *might* want a wideband, or at least a combined wideband + universal.

if feeding 2x universal into a recorder. it will depend whether all the wanted
recordings happen to be on transponders in the same "quarter" of the HH/HV/LH/LV
combinations of frequency and polarisation.

[alan_m]

A sky wideband limits the OP to Sky or one or two Freesat boxes.

A universal Quad LNB offers the choice of many more boxes including
those not branded Freesat but able to get all the Freesat channels and
over the air EPG, such as the Enigma2 boxes running something like OpenVix.

A Sky wideband with legacy universal outputs offers the choice of both.

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

[alan_m]

On 15/04/2022 09:51, Jeff Gaines wrote:
>

> I am trying to see if I could have a satellite dish to serve my Freesat
> box. As far as I can see from Googling I need to allow 5 degrees
> variation so point it at 247 degrees. Does this seem correct for
> Alderholt (3 mile west of Fordingbridge, Hampshire)? At this stage I'm
> just trying to see if it's feasible with trees/obstacle etc.
>
> Will an aerial installer be able to fit me a wideband Sky dish without
> signing me up to Sky?
>
>

To see if you have any obstructions
Go to https://www.dishpointer.com/
In the fist box type in your post code
In the second box select the satellite. 28.2E Astra 2E, 2F, 2G for Freesat
Press the search button
You should get a map or satellite image with a green line. This line
points to the satellite.
The map or satellite image is a user selectable option
Click on the green blob at the end of the green line and drag it to you
house or location where you are going to install the dish. You can zoom
in the map or satellite image.
There is a tick box labelled "show obstacle (line of sight checker)"
This puts a moveable red blob on the green line indicating the height
you need to clear any nearby objects.

Any installer should be able to install a sky type dish for any purpose.
It's not the dish that is wideband but the LNB attached to it.

If yo already have an old Freesat box it will not support a wideband LNB
- just a universal LNB - but go for a quad universal LNB.

It's only very recently the some Freesat boxes have supported the sky
wideband LNB or check your box before going down this (wideband) route.

[David Woolley]

On 15/04/2022 12:05, williamwright wrote:
> Stand at the proposed dish location and face due south, then divert your
> gaze about 28deg to the east of due south.

That would only be true fractionally away from the North pole, and if
the Clark belt was at, effectively, infinite distance, which it isn't.
(You have to be fractionally away, otherwise every direction is South!)
Given the 143° suggested elsewhere, you'd be quite a long way out.

You also have to consider elevation
<http://downloads.falcontechnical.co.uk/easyfind/Finding_the_elevation_for_your_location.pdf>,
as well as azimuth.

I'm surprised that there is no map of required azimuths that I can find,
just calculators. There are maps for elevation and for polarisation
skew. It looks like the main approach is to set the elevation then
simply sweep to find the azimuth.

[Robin]

On 15/04/2022 09:51, Jeff Gaines wrote:
>

> I need to allow 5 degrees variation

May be my misunderstanding but FWIW the magnetic variation from grid
North where you are is less than half a degree West[1]. You are close to
the grid origin at 2 degrees west so the variation from true North will
be much the same.

[1] http://www.geomag.bgs.ac.uk/data_service/models_compass/gma_calc.html



--
Robin
reply-to address is (intended to be) valid

[Jeff Gaines]

That is brilliant, thank you :-)

It shows the tree in my next door but one neighbour's garden with the
green line apparently clear of it, using the compass on my 'phone it's
marginal - 135 degrees clears it, above that it gets dodgy. I probably
ought to wait for the leaves to come out before I get an installer in.

My Freesat box is Freesat-4k-Recordable-PVR2020. The manual says it needs
the wideband LNB to record 4 stations at once. A dual LNB allows 2 at once
bit any more needs the wideband.

Thanks again to alan_m and everybody else, if I had decent broadband I
might try and do everything with that but it floats between 10 Mb/s and on
a really good day 30 Mb/s but that's rare.

--
Jeff Gaines Dorset UK

Indecision is the key to flexibility

[Andy Burns]

Jeff Gaines wrote:

> It shows the tree in my next door but one neighbour's garden with the green
> line apparently clear of it, using the compass on my 'phone it's marginal -
> 135 degrees clears it, above that it gets dodgy. I probably ought to wait for
> the leaves to come out before I get an installer in.

Try it yourself at ground-level?

[R. Mark Clayton]

On Friday, 15 April 2022 at 10:45:32 UTC+1, Andy Burns wrote:
> Jeff Gaines wrote:
>
> > I am trying to see if I could have a satellite dish to serve my Freesat box. As
> > far as I can see from Googling I need to allow 5 degrees variation
> 5° seems a lot.

It is - the satellites are 3° apart and alternate polarity, so you would be looking at the next but one.

> > so point it at 247 degrees. Does this seem correct for Alderholt (3 mile west
> > of Fordingbridge, Hampshire)
> Dishpointer says 143.3°

Both these figures seem improbable. The satellite is over 28.2E and Aldershot is less than 1° W, so by my calculation the dish would point approximately 146-147°

[R. Mark Clayton]

On Friday, 15 April 2022 at 11:29:39 UTC+1, Jeff Gaines wrote:
> On 15/04/2022 in message <xn0ngn6up...@news.individual.net> Jeff
> Gaines wrote:
>
> >
> >I am trying to see if I could have a satellite dish to serve my Freesat
> >box. As far as I can see from Googling I need to allow 5 degrees variation
> >so point it at 247 degrees. Does this seem correct for Alderholt (3 mile
> >west of Fordingbridge, Hampshire)? At this stage I'm just trying to see if
> >it's feasible with trees/obstacle etc.
> >
> >Will an aerial installer be able to fit me a wideband Sky dish without
> >signing me up to Sky?

Fitting a dish fitted easy. See elsewhere in thread about near proprietary LNB.

> Thanks for the replies :-)
>
> I screwed the maths up, I think the answer is 153 degrees (including an
> allowance of 5 for variation) as follows:
>
> 180 - 23 - 5 = 153.

Er Freesat position is over 28.2E NOT 23E

>
> I think I took the variation off twice then wrote 247 instead of 147, good
> job I'm not flying to the moon!
>
> I found:
>
> "The most common satellites in the UK are the Astra 2 satellites at 28.2E
> and Eurobird at 28.5E."
>
> However, that's meaningless to me, the compass starts at 0 and ends at 359
> or 360 depending how pedantic you want to be.

Centuries ago the world pretty much agreed that Greenwich would be the prime Meridien. Longitudes to the east would be written nnE and to the west nnW, although these days some write -nn for east.

The satellites are geostationary over the equator so their position is given as the latitude they are over,

For a satellite well to the east or west of your own position, you have to make allowance for the angle between you and the satellite (for 28E from 1W about five degrees,

>
> I suggested a Sky dish as with the wideband (Sky Q) version I can record 4
> channels (from memory) at a time. Doesn't happen very often that there's 4
> channels worth recording but does occasionally and as I'm starting from
> scratch I might as well do it properly. If there's a non Sky version that
> will do fine.

Normal Freesat or FTA receivers can normally only receive one or two channels at a time, however if you have a quad LNB, four cables and enough boxes then you will be able to do this.

Many TV's now incorporate a Freesat or FTA DVB-S receiver, sometimes two and can record one, while you watch another.

[R. Mark Clayton]

You also need the declination angle for the dish at the latitude and longitude for your location.

For a satellite overhead it is 90-latitude° and about 6-8°. So for Aldershot it is 29° - declination, which depends slightly on which satellite you are trying to recieve.

[R. Mark Clayton]

You can get true S by marking a shadow at Zenith, and you can get that from astronomy web sites / app's e.g. Skymap.

This is how I fitted my 1.2m steerable Gregoria Fibo right first time back in 1997.

[R. Mark Clayton]

Indeed, I had a tree grow in the way of my dish over about 15 years.

> Try it yourself at ground-level?

and also mount the dish high up if there are obstacles.

[charles]

In article <cc746939-e2a6-4573...@googlegroups.com>, R.

AlderHOLt = 1.83°W

[Java Jive]

On 15/04/2022 17:47, R. Mark Clayton wrote:
>
> Centuries ago the world pretty much agreed that Greenwich would be the prime Meridien. Longitudes to the east would be written nnE and to the west nnW, although these days some write -nn for east.
>
> The satellites are geostationary over the equator so their position is given as the latitude they are over,

Presumably a typo, ITYM longitude ...

> For a satellite well to the east or west of your own position, you have to make allowance for the angle between you and the satellite (for 28E from 1W about five degrees,

Yes, although my calculator page is no longer working (I'm working on
that, but having trouble with it), the rest of my satellite pages are
still relevant and may be helpful to the OP. The normal pages are
designed to give general information, the analysis pages show how the
necessary calculations are done:

https://www.macfh.co.uk/JavaJive/AudioVisualTV/SatelliteTV/SatelliteTV.html

--

Fake news kills!

I may be contacted via the contact address given on my website:
www.macfh.co.uk

[David Woolley]

On 15/04/2022 17:52, R. Mark Clayton wrote:
> You also need the declination angle for the dish at the latitude and longitude for your location.

You don't mean declination. Declination pairs with right ascension, and
is independent of location on the earth.

> For a satellite overhead it is 90-latitude° and about 6-8°. So for Aldershot it is 29° - declination, which depends slightly on which satellite you are trying to recieve.

I couldn't work out what these figures represent. 29° is in right
ballpark for the elevation of Astra1, we are talking about Freesat,
which is Astra 2.

Satellite dishes are normally pointed using alt-azimuth type
coordinates, although the term elevation tends to be used, rather than
altitude.

[alan_m]

What does the red blob tell you:) That will give the height the tree
needs to be to block the signal. The measurement is referenced to the
bottom of your dish so if mounted mounted fairly high up you may find
that the signal clears the top of the tree with ease.

I have a 3 storey block of flats approx 4 (terrace house) garden widths
away from my installation and I have my dish at the upstairs window
level. To block the signal the flats would have to be 18 metres taller
than where I mounted the dish. My neighbour, closer to the block of
flats has his dish mounted around 6 foot from ground level and he has no
reception problems.

[Jeff Gaines]

On 15/04/2022 in message <jbtpm6...@mid.individual.net> alan_m wrote:

>>It shows the tree in my next door but one neighbour's garden with the
>>green line apparently clear of it, using the compass on my 'phone it's
>>marginal - 135 degrees clears it, above that it gets dodgy. I probably
>>ought to wait for the leaves to come out before I get an installer in.
>>
>
>>
>
>
>What does the red blob tell you:) That will give the height the tree
>needs to be to block the signal. The measurement is referenced to the
>bottom of your dish so if mounted mounted fairly high up you may find that
>the signal clears the top of the tree with ease.
>
>I have a 3 storey block of flats approx 4 (terrace house) garden widths
>away from my installation and I have my dish at the upstairs window level.
>To block the signal the flats would have to be 18 metres taller than where
>I mounted the dish. My neighbour, closer to the block of flats has his
>dish mounted around 6 foot from ground level and he has no reception
>problems.

I could play with this tool all day :-)

Placing the line on the back wall near a corner, which would be ideal, I
have a green blob that says:

Satellite: 28.2E ASTRA 2E | ASTRA 2F | ASTRA 2G
Elevation: 25.2°
Azimuth (true): 143.3°
Azimuth (magn.): 143.3°

I found the height feature - it says 24 metres for height and the tree is
slightly under the height of the chalet bungalow ridge tiles so I will be
long gone by the time it gets to 24 metres.

Fascinating! Thanks again :-)

--
Jeff Gaines Dorset UK

I take full responsibility for what happened - that is why the person that
was responsible went immediately.
(Gordon Brown, April 2009)

[Java Jive]

Some words of caution. As others have pointed out, the (clusters of)
satellites tend to be spaced at intervals of about 3 degrees around the
Clarke Belt (the usual term for the geo-stationary equatorial orbit; BTW
*not* the Ecliptic, that's something else entirely). This doesn't leave
much room for error, and potentially there are a number of sources of
error in aligning a dish. While any one on its own may not be too much
of a problem, combined with others, it could be, so it pays to be aware
of such errors, if only to be able to know in any one particular case
either that they're not a problem, or how to eliminate them if they are.

It is a given that there will be some error in aligning a dish, because
no such physical process is ever done perfectly. The pros here will
probably have their own opinions based on their greater experience, but
based on mine I suspect that unless the dish adjustment mechanism is
particularly good or particular naff, about one degree may result from
that alone.

It's a long time since I used Dishpointer, but it works essentially to
the way mine did when it was working ...

There is often an offset between the overhead imagery overlay and the
underlying map, see the example page on my site linked previously, and
this could lead to quite significant error. If when you examine the map
you find that the map of the streets doesn't exactly coincide with their
position in the imagery, then you have two problems:
1) Which is more likely correct? I suspect most probably the map.
2) How much is it out, and how to compensate for it?

Further, the maths is done assuming the earth is a sphere, but it's not,
and, from memory, this introduces an error of up to half a degree at
mid-latitudes for satellites that are at mid-range azimuths east or west
of the location's meridian, reducing to zero error for satellites that
are over the meridian.

With Dishpointer there is potentially a third source of error, from the
use of photographs. Right from the first, I suspected that this
functionality was a gimmick of very limited real life usefulness, so
never tried to copy it. My reasoning is simply this: a photo's scale
depends on the focal length of the lens, focussing, etc, which vary from
camera to camera, and further the photo may not have been taken quite in
the right direction or pointing truly horizontally. If Dishpointer
don't know accurately the photo's scale, horizontality, and direction,
how do they know where to annotate markings on it?

[Dave W]

On 15 Apr 2022 10:29:37 GMT, "Jeff Gaines"

<jgaines...@yahoo.co.uk> wrote:

>There's only one neighbour with a dish, it's mounted on an extension roof
>and points at the house roof so may not be too effective. There is a large
>tree which I think may be in the way which is why I want to get a rough
>idea before calling an installer in.
>
>Thanks again.

When you say "points", maybe you are referring to the dish axis, but
often the LNB is off axis, and the incoming signal is at an equal and
opposite angle to the axis, i.e. over the top of the roof.
--
Dave W

[alan_m]

On 15/04/2022 22:11, Java Jive wrote:



> There is often an offset between the overhead imagery overlay and the
> underlying map, see the example page on my site linked previously, and
> this could lead to quite significant error.  If when you examine the map
> you find that the map of the streets doesn't exactly coincide with their
> position in the imagery, then you have two problems:
>   1)    Which is more likely correct?  I suspect most probably the map.
>   2)    How much is it out, and how to compensate for it?
>
> Further, the maths is done assuming the earth is a sphere, but it's not,
> and, from memory, this introduces an error of up to half a degree at
> mid-latitudes for satellites that are at mid-range azimuths east or west
> of the location's meridian, reducing to zero error for satellites that
> are over the meridian.
>
> With Dishpointer there is potentially a third source of error, from the
> use of photographs.  Right from the first, I suspected that this
> functionality was a gimmick of very limited real life usefulness, so
> never tried to copy it.  My reasoning is simply this: a photo's scale
> depends on the focal length of the lens, focussing, etc, which vary from
> camera to camera, and further the photo may not have been taken quite in
> the right direction or pointing truly horizontally.  If Dishpointer
> don't know accurately the photo's scale, horizontality, and direction,
> how do they know where to annotate markings on it?
>

Very easy to check the alignment of the map to the overhead street
image. Zoom out and pick 3 points of reference at the edge of the image
(place your finger on the computer screen) and swap between map and image.

I doubt if anyone installs a dish without some kind of meter to maximise
signal whilst moving the dish and even when tightening the mounting
bolts the meter will show any drop in level that can be compensated for.
I found when installing my dish knowing the exact bearing was of little
use as trying to use a compass up a ladder whilst attempting to look
down on the LNB arm was difficult. I used dishpointer to identify
something along the "green" line and pointing the lnb arm towards that
reference gave a starting point. It was then a matter of moving the dish
by a small amount to get a signal on the meter. I was already aware that
in my location, and with a sky type mini dish, that the LNB arm had to
be almost horizontal. The meter I used cost a fiver.
I probably spent more time compensating for dish movement when
tightening bolts than I did finding 28.2E.

Where dishpointer comes in handy is getting some feel about where you
can position a dish. As I previously indicated with a 3 storey block of
flats nearby dishpointer gave me a quick confirmation that positioning a
dish anywhere on the back of my property wouldn't be a problem.

[Paul Ratcliffe]

On Fri, 15 Apr 2022 09:30:02 -0700 (PDT), R. Mark Clayton
<notya...@gmail.com> wrote:

> It is - the satellites are 3° apart and alternate polarity

Polarisation.

[Brian Gregory]

AFAIK most satellites for satellite TV use both horizontal and vertical
polarization to double the available bandwidth.

--
Brian Gregory (in England).

[Brian Gregory]

Yes. Many types look, at least if you don't look closely and think about
it, as if they are pointing lower than they actually are.

Typically here, in Southern England, the satellite (Astra 2E/2F/2G at
28.2°E) is around 25° above the horizon.

https://www.dishpointer.com/
might be useful.

[Brian Gregory]

Myself I'd seriously think about a unicable LNB. Just one cable and with
a unicable capable receiver it pretty much does everything any other
type can do. Get one with some legacy universal connections too if in
doubt about whether you will always have unicable capable receivers.

[Andy Burns]

Brian Gregory wrote:

> I'd seriously think about a unicable LNB. Just one cable and with a unicable
> capable receiver

Maybe a technically elegant solution, but surely unicable receivers are more
rare than wideband ones? I suppose you could use a fancy multiswitch at the
bottom to fool a freesat receiver into thinking it's talking to a normal LNB so
you do get the EPG?

[alan_m]

On 16/04/2022 04:03, Brian Gregory wrote:

>
> Myself I'd seriously think about a unicable LNB. Just one cable and with
> a unicable capable receiver it pretty much does everything any other
> type can do. Get one with some legacy universal connections too if in
> doubt about whether you will always have unicable capable receivers.
>

If I was upgrading this is the route I would choose but I would also buy
at least one receiver with FCB tuners to take full advantage of the
technology.

The OP already has a receiver that supports the Sky wideband LNB.

[alan_m]

Enigma2 receivers support unicable but there are a lot fewer models with
FBC tuners so for many of these enigma 2 boxes it doesn't look (in
practical terms) different from having a universal LNB connected.

One advantage of unicable is being able to distribute the cable to
multiple receivers with the use of cheap splitters but again
distribution around the home may be sky Q like with a unicable LNB, a
receiver with multiple tuners (FBC) and "slave" boxes networked via
wi-fi using the main box facilities (tuners, EPG, hard disk etc.)

The sky wideband LNB or uniable LNB is probably the future, until 100%
streaming becomes the preferred method.

[David Woolley]

On 16/04/2022 03:43, Brian Gregory wrote:
> AFAIK most satellites for satellite TV use both horizontal and vertical
> polarization to double the available bandwidth.

It's not to fully double the bandwidth. Adjacent frequencies are
transmitted with different polarisations, but the same frequency only
uses one. I'm not sure if this really allows an overlap, or whether it
is to simplify receivers.

[Java Jive]

On 16/04/2022 01:06, alan_m wrote:
>
> Where dishpointer comes in handy is getting some feel about where you
> can position a dish. As I previously indicated with a 3 storey block of
> flats nearby dishpointer gave me a quick confirmation that positioning a
> dish anywhere on the back of my property wouldn't be a problem.

Oh yes, I'm not trying to say that tools like Dishpointer, and my own
when it was working, aren't very useful, I'm just advising due caution
when using them.

There is a tendency for people, particularly when they don't understand
something, to rely too much on its technology, I'm merely saying that
it's important to understand technology's limitations.

I could give myriads of examples, here are just a few ...

When doing calculations for maths and science O and A Level, it was
always drummed into us to have some ball-park figure of what the result
should be to check against the result that came from using log-tables, a
slide-rule, or a calculator. With the slide-rule, it's very easy to
lose track of the powers of ten, with the latter, it's very easy to
miskey an entry, and not notice it. With any of them, it's very easy,
one way or another, to come up with a nonsensical result.

Lie detectors are considered reliable in many US legal procedures, but,
when studying for Psychology as a subsidiary subject at uni, in one
tutorial we played around with one, and, based simply on knowing how
they work, I was able to fool the tutor running it as to the answer to a
question.

And of course there's the iconic example of our times, satnav! From the
tragic couple who drove off a pier in Germany because their satnav said
it was a bridge, or the laughable continental driver who entered
Gibraltar into his satnav, and ended up in a little village in Yorkshire
by that name (didn't he notice something might just be wrong when he had
to board a ferry to cross the Channel?), the examples are legion. Up
here, there's a road called Struie Hill, with three small bridges with
tight turns into and out of them along it, at least one of which is a
listed monument, and they keep getting damaged by artics because the
route is on their satnav. I wrote to the council suggesting that they
should try to get it removed from the satnav HGV routes or at least
listed as 'strictly access only', but never even received an
acknowledgement.

So by all means use Dishpointer and other similar tools, they can be
very helpful, but be aware of their limitations and don't treat them as
a latter day oracle.

[tony sayer]

In article <xn0ngn9gx...@news.individual.net>, Jeff Gaines
<jgaines...@yahoo.co.uk> scribeth thus
>On 15/04/2022 in message <xn0ngn6up...@news.individual.net> Jeff

>Gaines wrote:
>
>>
>>I am trying to see if I could have a satellite dish to serve my Freesat
>>box. As far as I can see from Googling I need to allow 5 degrees variation
>>so point it at 247 degrees. Does this seem correct for Alderholt (3 mile
>>west of Fordingbridge, Hampshire)? At this stage I'm just trying to see if
>>it's feasible with trees/obstacle etc.
>>
>>Will an aerial installer be able to fit me a wideband Sky dish without
>>signing me up to Sky?
>

>Thanks for the replies :-)
>
>I screwed the maths up, I think the answer is 153 degrees (including an
>allowance of 5 for variation) as follows:
>
>180 - 23 - 5 = 153.
>

>I think I took the variation off twice then wrote 247 instead of 147, good
>job I'm not flying to the moon!
>
>I found:
>
>"The most common satellites in the UK are the Astra 2 satellites at 28.2E
>and Eurobird at 28.5E."
>
>However, that's meaningless to me, the compass starts at 0 and ends at 359
>or 360 depending how pedantic you want to be.
>

>I suggested a Sky dish as with the wideband (Sky Q) version I can record 4
>channels (from memory) at a time. Doesn't happen very often that there's 4
>channels worth recording but does occasionally and as I'm starting from
>scratch I might as well do it properly. If there's a non Sky version that
>will do fine.
>

>There's only one neighbour with a dish, it's mounted on an extension roof
>and points at the house roof so may not be too effective. There is a large
>tree which I think may be in the way which is why I want to get a rough
>idea before calling an installer in.
>
>Thanks again.
>

Umm..

Satellites are marked in their position of degrees East and West of due
south thats 180 deg! so as near as dammit Astra 28.2 will be 180 Minus
28.2 is 151.8 on the conventional 0 at north 90 at east 180 at south and
270 west and 360 and Zero deg at North scale conversely a sat at say 12
deg West will be 180 PLUS 12 so 192 deg


As to will it clear a tree it might, as the satellites are a bit higher
than where the dish "seems" to point to.

As best you can sight along the axis of the LNB the gubbins thats on the
end of the arm thats on the dish and where that "hits" the dish then
that angle which is slightly below a level line imagine that angle now
coming off the dish as it were and pointing into space thats where the
sats actually are. A decent dish pointing prog will or might say aim at
151 deg and 40 or 50 deg elevation relative to the earth, aim that with
a protractor and is the line of that is above your tree then to will
work!..

Plenty of Vids on Youtube ion the subject!





--
Tony Sayer


Man is least himself when he talks in his own person.

Give him a keyboard, and he will reveal himself.

[David Woolley]

On 16/04/2022 14:16, tony sayer wrote:
> Satellites are marked in their position of degrees East and West of due
> south thats 180 deg! so as near as dammit Astra 28.2 will be 180 Minus
> 28.2 is 151.8

No they are not. They are labelled by the longitude that they are over
at the equator. In the extreme case, of someone on the equator, their
azimuth is 90° or 270°. If you are at longitude 0, on the equator, the
angle to them below the vertical will still be larger than their station
position, because it is measured from the Earth's surface, whereas the
satellite position is relative to the centre of the Earth.

At the exact poles, the azimuth will be the nominal position, but due
South will be indeterminate, so you will need to use the prime meridian
as the reference. (More of a problem is that the elevation will be
negative, by about 8.5°.)

Elsewhere, on the prime meridian, azimuth, for most practical targets is
likely to be larger than the nominal position, although, for 90° and
270° positions it will be slightly smaller, because azimuths 90° and
270° are along a parallel of latitude but the satellites are over a more
southerly one (northern hemisphere).

For the gory details of the maths, including corrections for the
non-spherical Earth, see
<https://www.ngs.noaa.gov/CORS/Articles/SolerEisemannJSE.pdf>. The
parameter used to specify positions is what the article calls
sub-satellite point longitude.

[williamwright]

On 16/04/2022 03:56, Brian Gregory wrote:

> Typically here, in Southern England, the satellite (Astra 2E/2F/2G at
> 28.2°E) is around 25° above the horizon.
>
> https://www.dishpointer.com/
> might be useful.
>

http://www.wrightsaerials.tv/reference/dish-screened-by-roof.pdf

Bill

[R. Mark Clayton]

Successive transponders use alternate polarisation (H & V)

For the adjacent satellites 3 degrees either side the polarisation is reversed (V & H)

This reduces adjacent channel interference on the same satellite and co-channel interference on adjacent satellites.

[R. Mark Clayton]

On Friday, 15 April 2022 at 18:14:35 UTC+1, Java Jive wrote:
> On 15/04/2022 17:47, R. Mark Clayton wrote:
> >
> > Centuries ago the world pretty much agreed that Greenwich would be the prime Meridien. Longitudes to the east would be written nnE and to the west nnW, although these days some write -nn for east.
> >
> > The satellites are geostationary over the equator so their position is given as the latitude they are over,
> Presumably a typo, ITYM longitude ...

Yes of course!

[R. Mark Clayton]

On Friday, 15 April 2022 at 18:41:15 UTC+1, David Woolley wrote:
> On 15/04/2022 17:52, R. Mark Clayton wrote:
> > You also need the declination angle for the dish at the latitude and longitude for your location.
> You don't mean declination. Declination pairs with right ascension, and
> is independent of location on the earth.

Another oops. On a steerable dish you mount the axis of rotation parallel to the axis of the earth and essentially point the dish parallel to the equatorial plane. However as the satellites are 22,000 miles away there is a small adjustment to account for the fact that they are not at infinity.
Or maybe not: -
http://www.geosats.com/polarmount.html#:~:text=Declination%20is%20the%20adjustment%20used,adjustment%20that%20many%20installers%20misalign.
seems the term is used for that angle too.

> > For a satellite overhead it is 90-latitude° and about 6-8°. So for Aldershot it is 29° - declination, which depends slightly on which satellite you are trying to receive.

> I couldn't work out what these figures represent. 29° is in right
> ballpark for the elevation of Astra1, we are talking about Freesat,
> which is Astra 2.

Astra 1 is over 19.2E, Astra 2 is over 28.2E
https://www.lyngsat.com/europe.html

$ky used to be on Astra 1 when analogue.

[Jeff Gaines]

On 15/04/2022 in message <xn0ngn6up...@news.individual.net> Jeff
Gaines wrote:

>Will an aerial installer be able to fit me a wideband Sky dish without
>signing me up to Sky?

I have learned a lot from this thread so thanks very much :-)

Just to summarise:

I have a Freesat 4K Recordable - and it worked fine at my previous house
from a Sky dish with a wideband LNB with two outlets, it was able to
record four programmes at a time.

It seems a dish will be viable here, it will point at a tree but over the
top of it so getting in an installer in won't be wasting his time.

I go for a Sky size dish with a dual wideband LNB.

I'd like the leads to terminate in a dual F Type outlet so I can use
flying leads. Sky installers would rather just run the leads through the
wall. Is a dual F Type outlet box workable?

Thanks again!

--
Jeff Gaines Dorset UK

The facts, although interesting, are irrelevant

[williamwright]

On 17/04/2022 14:28, Jeff Gaines wrote:
> I'd like the leads to terminate in a dual F Type outlet so I can use
> flying leads. Sky installers would rather just run the leads through the
> wall. Is a dual F Type outlet box workable?

Yes.

Bill

[Jeff Gaines]

On 17/04/2022 in message <jc2jck...@mid.individual.net> williamwright
wrote:

Thanks Bill :-)

--
Jeff Gaines Dorset UK

Those are my principles – and if you don’t like them, well, I have
others.
(Groucho Marx)

[NY]

"R. Mark Clayton" <notya...@gmail.com> wrote in message
news:ccbfc595-97a6-4310...@googlegroups.com...

What about the frequencies where there is a service on both H and V. For
example (for Astra 28.x): 11264H and 11264V, 11306H and 11306V, 11344H and
11344V, 11386H and 11386V, 11426H and 11426V. I presume the frequency
figures are nominal and that 11264H and 11264V are actually on slightly
different frequencies, but is it enough to avoid H versus V interference,
when everywhere else in the spectrum there is a gap of at least 10 MHz
between an H and a V.

When a dish is installed, is one the adjustments the rotation of the dish so
H and V on the dish are accurately aligned with the H and V signals (ie
adjust for max H and min V on a known H-polarised frequency).

[David Woolley]

On 17/04/2022 16:09, NY wrote:
> I presume the frequency figures are nominal and that 11264H and 11264V
> are actually on slightly different frequencies, but is it enough to
> avoid H versus V interference,

The signals are several MHz wide. You can't fit in two multiplexes
without most of them overlapping each other.

[David Woolley]

On 17/04/2022 16:09, NY wrote:

> When a dish is installed, is one the adjustments the rotation of the
> dish so H and V on the dish are accurately aligned with the H and V
> signals (ie adjust for max H and min V on a known H-polarised frequency).

The skew adjustment is normally done on the LNB mounting, rather than on
the dish proper. E.g. <http://www.satcure.co.uk/tech/LNB_skew.htm>.

[williamwright]

On 17/04/2022 16:09, NY wrote:

> What about the frequencies where there is a service on both H and V. For
> example (for Astra 28.x): 11264H and 11264V, 11306H and 11306V, 11344H
> and 11344V, 11386H and 11386V, 11426H and 11426V. I presume the
> frequency figures are nominal and that 11264H and 11264V are actually on
> slightly different frequencies, but is it enough to avoid H versus V
> interference, when everywhere else in the spectrum there is a gap of at
> least 10 MHz between an H and a V.

When there are signals on opposing polarisations it just worsens the BER
a bit.

>
> When a dish is installed, is one the adjustments the rotation of the
> dish so H and V on the dish are accurately aligned with the H and V
> signals (ie adjust for max H and min V on a known H-polarised frequency).

No the dish stays still. You twist the LNB (it's called polarity offset)
and aim for the best BER. Then you have to remember to tighten the LNB
clamp.

There used to be a problem with the old magnetic polarisers. Any given
voltage to the coil produced different polarity twist depending on
frequency. But nowadays the LNBs have two probes at right angles so that
doesn't happen.

Bill

[williamwright]

Each multiplex is err, I can't remember, about 12MHz wide I think. Very
wide anyway.

Bill

[R. Mark Clayton]

Correct - Transponders with the same polarisation do not overlap, but the transponders with the other polarisation sit in between. As long as your LNB is accurately set up then the polarisation will mean that on frequency the polarisation of the adjacent channel will be nulled out.

[R. Mark Clayton]

Just double checked - for $ky on 28E they used H & V on the same frequency on a lot of transponders - you LNB skew will need to be very accurate in this case.

[williamwright]

On 18/04/2022 12:15, R. Mark Clayton wrote:
> Just double checked - for $ky on 28E they used H & V on the same frequency on a lot of transponders - you LNB skew will need to be very accurate in this case.

That's right. Strangely all that happens (if the offset is done right)
is that the BER is a bit worse; not enough to matter.

Bill

[tony sayer]

In article <t3ekl6$8bu$1...@dont-email.me>, David Woolley <da...@ex.djwhome
.demon.invalid> scribeth thus

Yes all quite right but i was opting for a simple explanation rather
than write a book;!