vixen sphinx SX Polar axis scope help to set it up

[david61]

hello can anyone tell me in easy terms how to set up the SX Polar axis scope

i don't understand what the manual says

many thanks David

[Kaptain Klevtsov]

Could you tell us what it says and which bit you don't understand please? I've not seen one of these, but it can't be so far removed from the other kinds of polar scope.

Kaptain Klevtsov

[MartinB]

David, do you mean how to set it up within the mount (I don't know) or how to use it to align with celestial north (I do know!)

[david61]

helo yes how to set it up to celestial north please

dave

[MartinB]

David, I need to have my scope in front of me to sort out how to describe the process to you. It sounds complicated at first but once you have run through it a couple of times it is a doddle. I can line the scope up within 5 mins and it is very accurate as well. You need to know your longitude. Will send a detailed response this evening hopefully.

[MartinB]

Ok David, it's much harder to write an explanation than it is to use the thing! Towards the rear end of the polar scope you will see 2 rings, the forward one is the RA setting circle. Lock this with it indicating 0. The white ring running around the polar scope has 2 scales, one going all the way round with 12 sectors (the date scale) and another which just goes around a sector of the the ring which is the time zone off set scale. You will see that it is marked up to 20 either side of the centre east and west. If you are 5 degrees to the west of you the centre point of your time zone line up the 5 on the W side with the indicator point on the polar scope. This point should stay in place when you make your adjustments later on. You now have your polar scope ready for action.

You are going to be making some large swings in RA and if you have your scope mounted at some times in the year you wont be able to align without it getting in the way so do the alignment before mounting the scope.

Remove the cover from the objective end of the polar scope and swing the dec axis of the mount until the scope is fully showing. Line up your mount as accurately as possible using a compass or polaris as your guide. Check your latitude and use this to set the altitude of the mount. Also check that you have plenty of azimuth adjustment of the mount. REMEMBER WHEN ALIGNING YOU MOVING THE MOUNT IN ALT AZ NOT RA OR DEC. Once dark have a look through the polar scope, if you don't see polaris you will have to move the tripod around and possibly adjust the mount altitude until it pops into view.

Now comes the clever bit. You rotate the mount in RA until the RA time lines up with the date scale on the white disc. So for 7pm on 10th December rotate until the 19 (as in 1900 hrs) lines up with the marker 1/3 into the 12 sector on the white ring. Obviously if it is 19.10 on the 14th Dec you will need to make some appropriate fine adjustments.

Switch on the illuminator (if it works - if not you will need to shine a light onto the scope). You will see a reticle. The bit that you are interested in is the graduated line that moves out from the centre and comes to a small circle. The position of this circle may vary depending on the age of the scope. The offset of polaris is very slowly increasing. Mine is set for yr 2000 so I set polaris to the outside line of the circle. You should use the alt and az controls on the mount to bring polaris to the appropriate place on this line - probably the outside edge of the circle. You may have to loosen the bolt fixing the mount to the tripod to turn the azimuth knobs. When you retighten this polaris will shift again. This is a pain but you get used to it. And that is it, you have a well aligned scope.

The polar scope on the Vixen scopes is superb. Ron Wodaski rates it as the best Polar scope of all mounts bar the Takahashis - better than the Astro Physics ones!! Certainly I've found drift aligning doesn't add a lot at shorter focal lengths. I can go a couple of minutes with an ED80 with no apprecialbe dec drift when imaging.

This is a difficult thing to describe so sorry if I've confused you. If things are unclear just ask away!

[mbasonic]

MartinB,

This was extremely helpful. I have been trying to figure out this day/month and time alignment for a bit. I just bought an old super polaris c8, and the above is super informative. The one thing that I still am not quite sure about is the white mark on the polar scope itself. Mine seems to be roughly in the 7 oclock position while the RA is all zeroed out. I understand that the meridian offset is to be set on this white line before you turn RA for date/time. BUT, where is the white line supposed to be before this adjustment is done? and should the reticle be perfectly perpendicular/level inside the scope view? Sorry, for the long post, and I hope this post isn't 100 years old, LOL