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Tracker Menu
There are two items on the Tracker menu, Tracker Test... and Tracker Options....
Tracker test...
Allows you to point the antenna at a specific object, including the Sun, Moon, Jupiter and Saturn e.g. for tracker alignment or receiver noise checking. Note that actual location sent to the tracker is visible as a pop-up hint on the nominal location. You will find this useful for debugging and tracker offsets you program.
A quick way to point at an object is to double-click it. Be aware that this actually opens the tracker, points the antenna, and then closes the tracker for each click on the button.
This dialog allows you to track an object by automatically repeating the "point" function. Check the Point every checkbox and set the repeat interval you want.
In the registered version of the program, there are options that help you set up a rotor and antenna. A new tabbed dialog appears with three options:
Offset allows you to alter the values sent to the tracker by small offsets, and these are the values that you would want to permanently record in the tracker options dialog.
Position allows you to point the antenna at specific azimuth and elevation values, checking north, south etc.
RA/Dec allows pointing at a specific point on the Celestial Sphere.
Clarke Belt enables antenna position to be calculated for any geostationary satellite just by knowing its orbital slot, and allows you to point the antenna if you wish.
Chris Cadogan describes using this facility:
"You will have calibrated your tracker so that, for example, South is directly opposite North, 90 degrees elevation is exactly half way between opposite horizons and that North plus 360 degrees is the same place. After that, what remains is a fixed and hopefully small Alt Az pointing error. The 3 dB beamwidth of a 90 cm dish at 1700 MHz is about ten degrees, so you are aiming for a pointing accuracy of roughly one degree.
"As a useful starting point the sun is a strong noise source in the sky, and the shadow of a feedhorn on a dish is a reliable sanity check. Don't forget that at lower elevations the ground, trees and buildings can be as bright or brighter at 1700 MHz and can confuse signal readings.
"Point at the sun, use tracker->setup->azimuth-stop North South to select between normal and flipped mode, verify the feedhorn shadow falls on the dish centre point in both cases.
"Use the 'zero' checkbox to sweep the antenna back and forth between a zero and a chosen d.Az d.El offset to judge where the signal peaks. You'll see smaller peaks from the antenna side lobes. (To make this easier, you can now use the Z and X keys to zero and allow the offset, while you monitor the signal).
"By transferring the d.Az d.El offset setting that gives you the strongest signal to tracker->setup->general->antenna-offset you can iteratively refine the antenna pointing accuracy, working with smaller and smaller offsets from the offset.
"Finally, verify that sweeping from zero to a large offset makes the signal fall away smoothly. This is a useful check to do on a moving satellite."
Options...
Controls the tracker options