UKCampsite.co.uk member Vin Blanc has put together this fabulous guide to aiming a “Mobile” Satellite Dish using a Signal meter, for freestanding (tripod mounted) dishes. This could mean the end to frustrating failed attempts at getting a picture on your caravan or motorhome or camping satellite setup!
Important fact! Satellite dishes do not like trees or anything else blocking their line of sight to the satellite.
Trying to aim a Sat dish using only a “boy scout type” compass to achieve the bearings is nigh on impossible for someone who has never attempted it before! Unless you can have an eyeball on the TV screen whilst adjusting the
dish, you stand a better chance of winning the lottery than hitting the
required satellite.
Try to imagine your sat dish as a laser gun with a pencil beam shining up
into the sky. The satellite you are blindly trying to hit is about the size
of a dustbin lid floating somewhere in space about 24,000 miles away!If your dish therefore, is only a fraction off target you'll get nothing at
all. Unlike the old terrestrial TV where you could wave the aerial about
until you picked up a fuzzy picture and then improve it as you swivelled the
aerial backward and forwards.
Satellite doesn't work like that. You either hit the target and get a
perfect picture, or you miss it by one degree and get nothing at all.
To aim the dish it will be necessary to adjust the three dish settings
according to your geographical location.
Azimuth (Lateral positioning): - Standing near the dish with a
conventional compass in your hand is not going to achieve the required
accuracy. Fixing the compass on the dish will only cause the compass to be
affected by any steel components in the mounting bracket including nuts &
bolts, screws etc,. resulting in a false reading.
Elevation (Vertical positioning): - Any degree markings on the
mounting bracket can only be accurate when the mounting is perfectly
vertical to start with. If the mounting is not "plumb bob" vertical the
degree markings on the side cannot be true - Close perhaps, but probably at
least one or two degrees out
Skew (LNB position): - Important, but not as mega critical as Azimuth
and Elevation. On an “Offset” type dish (one with the LNB mounted on an arm
sticking out in front of the dish), skew is read and adjusted standing in
front of the dish with your back to the satellite. From vertical (0˚.), the
LNB should be turned clockwise. Note: the markings on the LNB normally
indicate (reading left to right) 25˚ 20˚ 15˚ 10˚ 5˚ 0˚
If you have a “Prime focus” or “Cassegrain” type dish (with the LNB at the
back) then you will need to turn the LNB anticlockwise (standing behind the
dish looking up at the satellite).
To obtain the required dish settings and line of sight from your location
click on
this link In the two boxes provided, enter in your location address (or
GPS co-ordinates). In the other box, select the required satellite e.g. 28.2 E Astra 2A/2E/2F (for Freesat & Sky). Click Go.
On the resultant “Google” map, drag the x at the base of the little balloon
to the position of your dish. (The line that appears is the direction of the
satellite). Now scroll down below the map and write down the resultant
Azimuth, Elevation and Skew settings. Note: The Azimuth compass bearing is
not really necessary when using a Signal meter. The simplest way to set up a
dish is to use a “Signal meter” or “Sat finder” as they are better known.
(Amazon sells the “SLx” meter for between £5 to £10.) No need to spend any
more than that.
Preliminary settings (The actual “hands on dish” bit).
Firstly, adjust the LNB skew to the required setting as described above.
Assuming that the dish mounting bracket is as vertical as possible, tilt the
dish until the required degree of elevation is indicated on the elevation
scale, usually stamped on the side of the dish mounting bracket. Tighten the
elevation clamping screws. If there are no scale markings on the mounting
bracket, provisionally set the elevation so that the dish itself is tilted
just slightly back from vertical.
Ensuring that the PVR/Digibox is switched off, connect the Signal meter in
line between the PVR/Digibox and the LNB. Preferably at the LNB end so that
the signal can be heard whilst adjusting the dish. Point the dish roughly
half way between east and south. (approx. 135˚ magnetic). Now switch on the
PVR/Digibox and TV to get a few volts up the cable.
The meter may or may not start to squeal immediately. If it does - adjust
the squeal down to its lowest possible volume level but just still audible.
If it doesn't - swing the dish very slowly a little further towards south
until it does. Adjust the squeal down to its lowest audible level and again
very slowly continue to swing the dish laterally towards south about an inch
at a time pausing for a few seconds before moving again.
Astra 2E should be the first satellite that you start to pick up and the
squeal should rise rapidly in volume as you move the dish till it reaches a
peak. With the squeal at its loudest, stop and lock down the lateral
(azimuth) dish setting and reduce the volume of the squeal back to “just
audible”.
Slacken the elevation lock again and fine tune the elevation setting by
gently tilting the dish backward or forward until the squeal again reaches
its peak. Lock off the elevation. When adjusting the elevation, be aware
that wherever you stop tilting the dish, it will drop just another fraction
under its own weight so try to allow for this.
Go check your signal strength and quality readings on the TV (note; the
“quality” reading is the most important one and should preferably be above
60%) and hopefully pour yourself a large G & T to celebrate your success!
Always bear in mind that the larger the dish, the more accurate and diligent
you need to be. When fine tuning for the ultimate “signal quality” reading,
always move the dish just a tiny fraction at a time and pause for a few
seconds to give your “Digibox” (receiver) time to adjust to the new setting.
It’s always much easier if you can see the TV screen whilst fine-tuning. If
you can’t, - get someone to sit in front of the TV to yell “better” or
“worse” according to the strength and quality readings.
Aiming a Satellite dish is not mega difficult and gets easier each time you
do it – honest!
Now that you have mastered the art of aiming the dish (Yes!) using a
Signal meter (Sat finder), you may want to consider the following:-
A simple "gismo" to make setting the elevation a lot quicker and easier.
When you have to set up your Sat dish at each and every site visited, the
exercise can be made a lot quicker and easier with the following home-made
"gismo" to quickly set the elevation. This effectively leaves only the
Azimuth (lateral) setting to worry about.
You will need to purchase an "Inclinometer" (or Angle Finder) available from
Amazon or www.brymar.co.uk or www.pulsat.co.uk (about £10) which, when
mounted on the dish, will show (in degrees) the angle at which the dish is
tilted above horizontal (the elevation).
You will also need to make or purchase a small steel right angle bracket
about 10cm x 10cm x 2cm wide.
Mounting the bracket on the dish depends very much on the type of dish that
you use.
Here are two examples of brackets mounted on different types of dish.
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| Picture 1 |
Picture 2 |
In picture one, a thin slot has been carefully
drilled and filed out in the rim of the dish to accommodate the
bracket which can easily be slotted in when required and removed
once set-up has been completed.
In picture two, the bracket is simply a "push fit" into place and
can either be removed or left permanently in place.
The "Angle finder" has a magnetic base so sits happily on the steel
bracket however steeply the dish is tilted.
Note 1: The "offset"
angle of each dish is unique to that particular dish and therefore,
each dish should have its own specific bracket.
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| Picture 3 |
Note 2: Once the bracket (more clearly shown in picture 1) has been bent
to the correct angle, it will also indicate, the true "line of sight" to the
satellite!
This is how I made my brackets:-
To initially set the angle of
the bracket to suit the offset of the dish, I erected the dish on
the patio at home then aimed it at the satellite initially using a
"Sat Finder". Finally by selecting the TV channel with the weakest
signal (as indicated by the signal strength and quality bars on the
TV screen), I finely adjusted the tilt of the dish until I had
achieved the best possible readings for the Astra 2E satellite (for
Freesat and SKY). |
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Knowing that the elevation for Astra 2E where I live (New Milton, Hants)
is 25.4°, all that needed to be done now was to clamp the bracket in a vice
and by trial and error bend it, so that when remounted on the dish (with the
"Angle Finder" magnetically attached), the needle on the "Angle Finder"
pointed to 25.4°, (or approximately halfway between 25° and 26°).
Obviously, you would need to use the elevation figure for your own location
and you can get that from
this link
Having done all that, your bracket should now be calibrated to suit the
offset of your dish. Wherever your wanderings may now take you, either in
the UK or abroad, you only need to know the angle of elevation.
It takes only 30 seconds to mount the "Angle Finder" on the bracket and tilt
the dish to the exact degree of elevation required. As it is not always
possible to access the above web site from the caravan, I made up my own
“elevation” maps from maps of the UK and France which clearly show the major
roads and towns.
| Using the above web site, and burning a lot of midnight oil, I
was eventually able to draw in each degree of elevation from the
north of Britain (17°) all the way down to northern Spain and
Corsica (38°). This is just one of a series of A4 size pages that
I now carry in the caravan.
I simply have to pinpoint my current location on the map and note
the relevant degree of elevation printed on the elevation lines:
Simples! |
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This now leaves only the Azimuth (lateral) setting to determine, which
should now be very much simpler using your "Signal meter" or perhaps better
still, a “marine” type compass, possibly mounted similar to this.
Made from wood and aluminium, this compass mounting bracket requires a
little practical skill to make but is not too difficult for the average
handyman. This bracket comprises of an inverted wooden “T” with an aluminium
right-angle fixed to the top with non-ferrous metal screws.
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Picture 4 |
Picture 5 |
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| Picture 6 |
Picture 7 |
As with the elevation “angle bracket”, the dish needs to be set up at
home and adjusted until the very best signal strength and quality readings
are showing on the TV screen. Always adjust whilst tuned in to the TV
channel with the weakest signal.
With the compass provisionally mounted (Picture 4) and without moving the dish, gently turn the compass base until the correct compass bearing (in accordance with Dishpointer.com) is indicated (by the "lubber line") on the compass.
The compass base should then be fixed firmly and permanently to the mounting
(Picture 6).
Note: For obvious reasons, this method of setting the azimuth will not work
on steel satellite dishes. Likewise, if the magnetic based “angle finder” is
accidentally left in position. (Picture 7).
The time and effort saved in setting up the dish on each caravan site is
well worth the time spent at home bending the small steel bracket and making
the inverted “T” compass mount but remember -
Making these two “Gismos” only needs to be done once!
It has been recommended and briefly described by David Sullivan on his satelliteforcaravans web site but should there be anything not quite clear – just ask me – the
originator!
Aiming a Sat dish using the co-ordinates from “Dishpointer.com” and my two
home made “Gismos” will guarantee finding the Astra 2E satellite (or any
other satellite for that matter) each and every time without even having to
switch-on the TV.
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