I dare say that many of you will have been using the fine summer weather to fiddle
with and tweak your satellite dishes, although I suspect even more of you have
been sitting out in the sun with a nice long drink!
Others may well have been pursuing sports feeds looking for an elusive football
match, basketball game, etc.
Sooner or later we end up playing the game of hunt the satellite, and it's
particularly difficult if the bird we are looking for remains resolutely silent
on the channel we are tuned to, or even worse, is in inclined orbit.
Regular readers will have gathered by now that I'm not a great fan of those
cheap satellite finder type meters, which cannot differentiate one satellite
from the next, or even from the sun. When the satellite you are seeking is close
to another perhaps more powerful one it's very easy to peak the dish position
up on the wrong satellite entirely.
But, providing that you have a conventional dish motor and not on of these
new-fangled DiSEqC ones help is at hand. Not only that but this technique will
stand you in good stead on those cold wet winter evenings when you fancy watching
a bit of chain-saw racing or somesuch.
First you need to write down all of the motor count positions of the satellites
that you are sure of. The more satellites you have tracked down the better the
end result will be.
This has two benefits.
Firstly you will be able to recover all of your vital satellite position information
should anything happen to your receiver, like an inadvertent factory reset,
or worse!
Secondly you will be able to plot a graph of the dish motor counts against
satellite positions. You can use good old-fashioned pencil and graph paper for
this - but if you are feeling really flash you can use something like Microsoft
Excel for a prettier result.
When you've done that it should look something like this.
Click on picture to enlarge
Don't be surprised that it isn't a straight line, but you should expect to
see a fairly smooth curve, with no sharp jaggies in it. If your curve isn't
smooth then something has gone wrong somewhere, most probably you have made
a simple transcription error when entering the data!
This is my own satellite position data and the eagle-eyed amongst you may have
spotted an anomaly around the 5°W to 8°W area of the graph. This came
as a bit of a surprise to me, and I think that it's because of my incessant
attempts to get a better signal off Nilesat at 7°W! The two French satellites
at 5°W and 8°W are such powerhouses that I appear to get a marginally
cleaner signal if my antenna is slightly misaligned from 8°W. Well that's
my theory and I'm sticking to it!!!!!
By now I'm hoping that the bird finding method is now self evident, all you
need to do to find a particular satellite is to read off what the correct motor
count should be for any satellite position by consulting the graph. That is
exactly what I did for Intelsat 801 in this example - so now I'm off to see
what I can find there!
The Professor
|