Thread: FreeSat.
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williamwright williamwright is offline
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Default FreeSat.

On 07/06/2021 09:11, T i m wrote:
Yeah, I think they are also called polar mounts, slightly different to
an astronomical equatorial mount.


The geometry is a bit weird. Really big dishes take quite a bit of
setting up.The thing sweeps across the arc by virtue of a fairly simple
pivoting arrangement, but then there has to be 'declination offset' to
compensate for the fact that the dish is not at the centre of the earth.
It's done by setting the tracking arc a bit high then adjusting a offset
to drop the dish down a fixed amount on the swivelling mount. Then you
start to think about polarisation offset!

Bill