Basic setup ofsatellite antennas

Basic setup ofsatellite antennas
In most cases it is sufficient to
simply unplug the analog receiver
and connect the antenna cable to
the new digital box. As a general
rule the antenna alignment should
remain unchanged, unless the
dish has not been aligned properly
in the first place and needs fine
tuning. All this should not pose a
big problem.
If a new antenna has to be set
up for the first time, however, the
absence of any analog signal will
create some difficulties. Since digital
signals are much harder to find
than analog signals, the search
for the correct antenna angle
and alignment will invariably take
longer than before. In the analog
days it was quite easy to simply
move the antenna until a blurry
image appeared on the TV screen.
A little fine-tuning was all that was
needed until the TV screen showed
a clear picture. This is not possible
any longer with digital satellite
reception. Weak digital signals do
not translate at all into a picture
on the screen which remains black
until the signal strength has passed
a certain threshold (approximately
30%) and a crystal clear picture
appears on your TV set.
If you don’t know where exactly
to search for your desired satel-
The digitalisation of satellite channels is progressing rapidly
and soon there will be no more analog satellite channels in Europe.
Once the conversion is completed old analog receivers are rendered
useless and have to be replaced by digital set-top boxes.
lite your search will be in vain. As
long as there are still some analog
signals left, an old analog receiver
for the antenna alignment will
do a perfect job. But what to do
after the switch-off of all analog
signals? In this case a systematic
approach is required.
If only a single satellite is to be
received the antenna alignment
can be fixed at the particular position.
In order to align the dish
correctly the elevation has to be
adjusted properly using the scale
on the antenna pole. However, the
correct elevation depends on the
local degree latitude. Below are
the values for a satellite that is
in a precise southern position (in
a precise northern position when
seen from the southern hemisphere):
Latitude 15 20 25 30 35 40 45 50 55 60 65
Elevation 72 67 61 55 49 44 38 33 27 22 17
For a satellite that is some
degrees to the East or the West
the elevation decreases. For a
10-degree deviation the elevation
decreases by a maximum of one
degree.
Next, the hunt for a signal can
begin by moving the antenna
towards the desired satellite’s
position. In order to check the
success of the search on the TV
screen the digital set-top box has
to be tuned into a channel on that
satellite. Of course new receivers
have a pre-programmed channel
list, so selecting a valid channel
should not be a problem. However,
since transponder data do
change in the course of time it is
advisable to check the pre-stored
data against the current SatcoDX
frequency chart.
Unfortunately there is no
scale on the pole for turning the
antenna to the East or the West.
This makes finding the correct
alignment as difficult as with a
motorised antenna which allows
receiving a great deal more channels
without additional costs

BEGINNER SECTION to install diseq motor
The motor is what actually moves the antenna between the various
satellite positions and is installed in between the antenna mast and
the antenna mount. It is designed such that the axis of rotation is
aligned with the North Star. This type of mount is often referred to as
a Polar Mount. As a result, azimuth and elevation do not have to be
adjusted individually. Instead, the antenna rotates on only one axis.
The antenna motor is installed on the already existing vertical
mast. The local latitude position of the location is then setup on
the motor’s scale thus aligning the axis of rotation in the correct
position. Similar to a fixed antenna installation, the elevation scale
on the antenna mount must be set for a satellite as close to south
as possible. In the southern hemisphere you would be looking for a
northern-most satellite. The selected satellite should lie within 5° of
your southern-most position; the southern-most position being equal
to your local longitude.
For example, if your local longitude is 73° west, then the satellite
you select should be located within +/- 5° of 73° west, or within the
range 68° to 78° west. The elevation setting will be completely different
than the original elevation setting. The actual value is almost
completely independent of your local latitude position and is related
much more to the construction of the motor. The post on the motor
onto which the antenna is mounted is bent at an angle. The actual
angle of this bend depends on what type of motor is used. STAB
motors, for example, have a 30° bend while others such as MOTECK
have a 40° bend in their antenna post.
Latitude 15° 30° 40° 45° 65°
Elevation Original 72° 55° 44° 38° 17°
STAB 30°-Angle 27° 25° 24° 23° 22°
MOTECK 40°-Angle 37° 35° 34° 33° 32°
Before starting to look for a signal, the antenna motor needs to
be properly aligned. With the help of a compass, the entire motor/
antenna assembly is rotated on the mast until the zero-point on the
motor’s scale is pointing south (pointing north in the southern hemisphere).
From here the search for a signal can start. Simply set the
receiver to a known active channel. It might not be a bad idea to first
verify the channel data with the SatcoDX Charts.
The first step would be to activate the DiSEqC 1.2 function in your
receiver and also, if available, the USALS function.
USALS greatly simplifies the antenna setup. It simply asks you for
your local geographical coordinates and calculates the satellite positions
on its own using a complex mathematical formula. The receiver
then drives the motor directly to the selected satellite position. Once
you have a signal, you need only finely adjust the antenna mount and
horizontal position (on the mast itself) for maximum signal. If the
initial southern setting was slightly off, it would now be corrected.
Once the first satellite is perfectly set, all the other satellites in the
arc would also be automatically set as soon as the orbital position of
these additional satellites is entered into the receiver.
Without USALS, the alignment of the antenna system is somewhat
more difficult. DiSEqC 1.2 drives the antenna to the selected satellite
position in almost the same way. But since the local geographical
data is missing, the motor drives to a satellite position based on the
prime meridian and the equator.
Therefore, when aligning the motor for the first time – and then
again later on with all the other satellite positions – alignment with
the actual satellite position has to be achieved with the motor commands
“move east/west”. Because of these difficulties, manufacturers
of these motors make available helpful software on their web
sites that enable you to easily calculate the true position of a satellite.
TELE-satellite has also made a version of this tool (“USPOS”) available
for download at www.TELE-satellite.com/Uspos.exe
Motorized Systems
Setting Up
a Motorized Antenna
Heinz Koppitz
Every satellite antenna that is only able to receive one satellite and is thus fixed on only that
single satellite can be upgraded to a motorized antenna giving you access to numerous additional
satellites. The antenna itself doesn’t change, nor does the attached LNB. The antenna motor is
the only extra part that you will need since most modern receivers already come with the required
DiSEqC 1.2 protocol. Some boxes make this even easier with the USALS protocol, also called
DiSEqC 1.3 or GoTo X.
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