How to find the Satelite
There are various antenna manufacturers
out there and a variety of ways to adjust the antenna itself. One
of the key differences is weather the antenna is OFFSET or not. There are also the two different types
of satellites as a variable; two major SATELLITE differences
are weather it is LINEAR or CIRCULAR. To find a LINEAR satellite is a bit more difficult as you are dealing with
AZ IMUTH, ELEVATION and the FEED
ROTATION. With a
circular satellite, once the feed is set to either RHCP or LHCP, the only factors you are dealing with are AZ and
EL – so, it’s MUCH easier as long as you are
dealing with a competent teleport.
First, it
is extremely important to make sure that you are NOT TRANSMITTING – the
best thing to do is to disconnect the transmit cable from the back of the modem!
Assuming you
have a 2.4M offset Prodelin antenna which has an ELEVATION offset of approx 22.5deg
in EL; as an example; to point to pas1r (45W), a LINEAR satellite,
from Lagos Nigeria you need to set your antenna to:
AZ :264.2
EL:34.19...but with 22.5 offset, you actually set elevation
to about 11.5
The teleport you are dealing with SHOULD be able to provide
the AZ and EL readings based on your physical location. Iron
Link will always provide these for you.
First ensure
that the teleport is transmitting the signal to you and that your equipment is
properly configured to receive that signal.
Next, I would
recommend setting the AZ to 264 but leaving the AZ bolts a bit loose (all the AZ bolts including all the bolts around the neck of the pedestal), when all the
bolts are loose enough that you can swing AZ back and forth without too much
effort.
Now, set the
EL to 9.5deg. The EL setting is IMPERATIVE, so, take your time and set
it as perfectly as possible, the more accurately you set the EL, the easier it
will be to find the satellite.
Now, SLOWLY
swing AZ to 244 and then to 284 (basically +/- 20 deg) while
watching the input level on the modem and the green LOCK light....if no luck,
then put AZ back to
264 and rotate the feed by about 45 degrees and repeat the AZ swing
from 244 to 284....if still no luck, then rotate feed ANOTHER 45 degrees and
swing AZ from 244 to 284 again....if still no luck then put AZ back
to 264 and increase el to 10.5 - REPEAT PROCEDURE at 10.5, ie; swing AZ 244
to 284 - if no luck then rotate feed 45 degrees and swing 244 to 284 - if still
no luck then rotate feed another 45 degrees and swing AZ 244
to 284 - if still no luck then move EL to 11.5 - now REPEAT
PROCEDURE again....if no luck, change el to 12.5 - now REPEAT
PROCEDURE again...if no luck, change el to
13.5 - now REPEAT PROCEDURE again.
If you were
trying to find a CIRCULAR satellite, you would use the
same procedure above except you would NOT be rotating
the feed.
If you haven't
seen any fluctuations in input level by now, and/or you have not LOCKED to the
teleport signal, then one of four things are possible:
- There is a magnetic field which
is throwing your compass WAY off and hence your AZ reading
is WAY off...in this case, you may need to repeat ALL
OF ABOVE but make the AZ swing considerably larger...ie;
instead of +/- 20 degrees, you may want to go +/- 40
degrees?
- Something is BLOCKING LINE OF
SITE - keep
in mind, you need clear line of site during the entire
RANGE OF MOVEMENT that you are doing above!
- Something
is very broken - I DOUBT THIS as; if you purchased the
equipment from Iron Link, it was completely tested BEFORE
being shipped to you.
- The teleport is not transmitting
the signal – its am AZ ing how many incompetent teleports
are out there…so,
if you have tried the above with no luck…it’s
VERY possible that the teleport is not doing what they
said they are. You should request that
the teleport confirm the parameters of their transmission
AND that they confirm with the satellite operator that
the signal is present on the satellite and that it is
at the proper power level. Iron Link will
have ALREADY done this BEFORE you are even given any
of the parameters.
Bart Leichardt
Iron Link Communications
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