AUTOSTAR INFORMATION Last updated: 31 January 2004

Polar home position for southern observers

Date: 1/29/04, 01:58
From: telkomisdn11311@telkomsa.net
I've been playing with my ETX in polar mode, and thought some comments
on the polar home position for southern hemisphere observers might be
appropriate.

An observation - If southern observers place the ETX control panel on
the western side of the mount (as is recommended for northern
observers), the home position has the eyepiece pointed toward the
ground. This makes it impossible to look through the optics, so I
decided to try a different approach.

It worked for me - my scope's running a patched romware version of 2.6E

1. Mount the ETX with the control panel on the _eastern_side_, with the
tube pointed roughly at the celestial equator.

2. Loosen the RA lock, and rotate the scope around the the RA axis in a
counter-clockwise direction as viewed from the south celestial pole.
When you get to the hard stop, rotate the scope around the RA in a
clockwise direction until the scope is pointed at the ground (roughly
100°). The eyepiece will be pointed toward the sky. You now lock the RA
axis.

3. Next release the declination lock, and point the scope at -90°
declination, so that the scope is pointed approximately at the south
celestial pole.

4. The scope is now in polar home position, and you can wake it up using
the Autostar. I found that an easy alignment and high precision pointing
was more than adequate for a night's viewing.

I also found that performing a precise alignment - as detailed on Bruce
Johnston's pages ( http://members.aol.com/ccdastro/goto-tests.htm ) will
help enormously.

Clear skies
Bruce D.

Midrand, ZA

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