Polar Aligning The 12" SCT

[leon]

Hi All

This is probably a doppy question, so it's ok to shake your head in disbelief, however i have never used one of these instruments before, so i was wondering, seeing that we life in the southern part of the world, is there something special i must do to line up with the South Celestial Pole.

The manual only refers to the Northern Hemisphere.

Do i have to tell the scope that i live here or will it automatically detect that and do a polar align using my home coordinates

Cheers leon..Now don't laugh

[[1ponders] (Paul)]

If it's the GPS version it's should be pretty straight forward. When you set it up try to have one leg pointing as close to north as you can work out (10 deg west of magnetic north will be close enough). Then mount the scope with the control panel on the south side of the mount directly opposite the leg.

Undo the Azimuth lock and manually turn the scope as far as it will go one way. Then come back all the other way and count the number of turns it takes. Then come back half way and lock the Azimuth with the forks and base lined up.

Release the Dec lock (hold the tube so it doesn't drop unexpectedly) and set the tube level.

From this point you should be able to simply turn the scope on and run with the automatic alignment. Hint: if it slews to a star for alignment and it says something like "Slew to the brightest star and press Enter" and you can't tell which is the brightest star, the press one of the arrows (V or ^) at the bottom of the controller to move to another star area that might be brighter.

Hope that helps.

[[1ponders] (Paul)]

Btw are you using it with a wedge or just in Alt/Az setup

[leon]

Thanks Paul, sorry it took so long to answer your question.

At the moment i will be using it in the Alt/Az mode, but eventually will be looking for a wedge, to fit onto a peir permantaly

[mick pinner]

Leon, have a look at the ASV site www.asv.org.au there is one for sale for $500.00. classifieds on the left side menu.

[AndrewJ]

Gday Paul / Leon

Re

Undo the Azimuth lock and manually turn the scope as far as it will go one way. Then come back all the other way and count the number of turns it takes. Then come back half way and lock the Azimuth with the forks and base lined up

.

If it is a GPS scope, then this is slow and overkill.
All you need to do is set the OTA to DEC = 0 then rotate on the RA axis till the diagonal/EP/camera is directly over the control panel.
Due to the position of the RA hardstops, there is only one way you can get to this position.
Thus just try to slew scope "gently" to this possie ( the stops really clunk when you hit them at speed )
If it hits the stop, go other way :-)
Done
( Unless yr on a wedge, in which case, you then reset the OTA to DEC = -90 ready for aligning )

As for Leons original question
If the GPS is on ( or you have manually entered/selected yr site ), it will detect yr latitude, and determine how to do the polar align from that. You follow the Nth hemi instructions, but replace Polaris with Sigma Octans.
Or you can cheat, ( lotsa different methods )

Andrew