ETX90-autostar

Ask your fellow astronomers to solve your telescope queries

ETX90-autostar

Postby Steve Dean » Sat Apr 15, 2006 9:10 pm

I've finally tried using the AutoStar (in Alt/Az) on my new ETX90 - with only partial success;
I expect a few more goes will be required before I get the hang of it.
Also, I imagine it is fussier about how you set it up (initially) than one might want to imagine;
my next test will be to use it in polar alignment - though it sounds likely that this will be more useful for tracking objects in high-maginfication (especially if I want to take photos) than merely 'finding' things as it is not quite clear where you start when using the alignment techniques in this mode (i.e. where do you point the 'scope' to start with?).
Exciting times ahead - I hope!
CJA
Steve Dean
 
Posts: 54
Joined: Tue May 10, 2011 10:07 pm

RE: ETX90-autostar

Postby petern » Sat Apr 15, 2006 10:50 pm

Hi Chris,

Just sold my ETX after a year or so of fun with it. The secret is in the set up and carefull centre of the cal stars. One of the best sites I found for advise and help was Mike Weasners ETX site and his book "Using the Meade ETX" both full of great info for using the ETX and AutoStar.

Hope you have many more happy clear skys with the ETX.

Peter
petern
 
Posts: 18
Joined: Mon Feb 13, 2012 6:27 pm

RE: ETX90-autostar

Postby Steve Dean » Mon Apr 17, 2006 8:56 pm

I'll check out the book (and the site);
thanks
C
Steve Dean
 
Posts: 54
Joined: Tue May 10, 2011 10:07 pm

RE: ETX90-autostar

Postby barnardstar2 » Wed Apr 19, 2006 1:00 am

There is a very small and insignificant arrow ^ on the base of the scope just below the movable band that's marked off in hours 0-24 this should point NORTH.

I set up the scope up on a tripod so that the ^ and scope points towards the pole star and I turn the scope until the objective lens is over this mark which ensures that the scope is mid travel ( it only turns round 1 3/4 turns). set it up so that the lens points North and the plate with the On switch and Autostar connections faces East.

Then line up the scope according to the manual or follow Weasners website instuctions from people like Clay Sherrod, training the motors is quite inmportant to get rid of backlash etc.

[url=http://www.weasner.com/etx/menu.html] http://www.weasner.com/etx/menu.html[/url]


Most of all have fun.
barnardstar2
 
Posts: 213
Joined: Mon Feb 13, 2012 6:27 pm

RE: ETX90-autostar

Postby Steve Dean » Wed Apr 19, 2006 5:23 pm

Thank you;
in fact I've also dowloaded a better manual from the Meade website - the booklet that comes supplied is ok but not all of it, I feel, is terribly clear.
I think there may be the odd misprint as well (not to mention basic bad grammar such as split infinitives etc.!!)
Cheers
Chris
Steve Dean
 
Posts: 54
Joined: Tue May 10, 2011 10:07 pm

RE: ETX90-autostar

Postby wgater » Thu Apr 20, 2006 5:33 pm

Chris,
As Peter says Mike Weasner's site [i]is[/i] very helpful, and he also has a book published by Springer (I think) on using the ETX. Stick with it though, because once you have familiarised yourself the 'home' position and how the autostar aligns and tracks you'll be laughing. It really is a great setup and the Autostar is a great piece of kit![/left][left] [/left][left]Will[/left]
wgater
 
Posts: 1072
Joined: Mon Feb 13, 2012 6:26 pm

RE: ETX90-autostar

Postby Steve Dean » Thu Apr 20, 2006 8:53 pm

Thanks Will,
there is also the New ETX Guide (as sold by Skyview).
Perhaps that's a bit more explicit.
I'm sure I'll get the hang of it sooner or later!
Chris
Steve Dean
 
Posts: 54
Joined: Tue May 10, 2011 10:07 pm

RE: ETX90-autostar

Postby Steve Dean » Fri Apr 21, 2006 11:53 am

whilst on the subject of Autostar;
is there a simple way to ask for the tracking of a manually found object?
There seems to be nothing in the manual that answers this point directly - so far as I've been able to interpret; yet this strikes me as being a fairly fundamental requirement, especially if you are seeking out things to photograph.

Chris
Steve Dean
 
Posts: 54
Joined: Tue May 10, 2011 10:07 pm

RE: ETX90-autostar

Postby wgater » Tue Apr 25, 2006 9:43 pm

Hi Chris,

Sorry for the late reply I haven't checked this thread in a while! If I understand correctly, your question is - Once an object (which hasn't been "goto'd") has been manually slewed into the field of view, will the Autostar track it?

The answer is, in my experience, YES quite reasonably. Sometimes the Autostar has a tendancy to move about a tiny bit (at a very slow slew rate) after you've done this before deciding that you probably meant to manually move it anyway! (Don't know why it does this it's not mentioned in any manual). If you were tracking a star etc. then the Autostar should track reasonably. However if you plan to do astrophotgraphy, like most telescopes, you will need to guide the scope with the keypad. This would have to be done either on a very bright star through the finder or using a reticle (An illuminated sight in the eyepiece) on a guide scope(You can't do this if you are using a camera on the rear port because the mirror is flipped); probably not a good idea on the little ETX[:)].

The above will only work if you align the telecope as per normal and let it track. Perform a few goto's and centre them up. The Autostar may adjust depending on what model it is. Then you can use the keypad to slew to a different 'manually found object' and the computer will [i]still [/i]track that object. The Autostar should track reasonably as the drives are only counter-acting the movement of the stars (actually it's the rotation of the Earth) and not tracking each object individually.

Hope this helps. It all seems a bit tricky but give it lots of practice and you'll be fine. Just post if you need more help.

Will
wgater
 
Posts: 1072
Joined: Mon Feb 13, 2012 6:26 pm

RE: ETX90-autostar

Postby light bucket » Mon May 01, 2006 11:20 am

Hi Chris,

I have been usin an ETX105 for 4 years and have found it to be an excellent scope. The only thing I didnt like was the focus knob (difficult to get to at high alt angles ), I have replaced it with a home made flexible extension, I used a section of car acellerator indicator cable, very flexible but little torsive play. There are many different instructions on Mike Weasners website (as quoted by barnardstar2)
As for the autostar, as the other guys have said it is all about acurate alignment, but eventually I found that it takes a bit of the fun out of astronomy, just dialling in what you want to view and pressing "goto" is OK for bright objects but there is no "discovery" for deepsky stuff.
I am sure you will enjoy using the ETX, be sure to enhance the pleasure by doing some DIY upgrades.

Clear Skies
light bucket
 
Posts: 17
Joined: Mon Feb 13, 2012 6:28 pm


Return to Equipment Advice

Who is online

Users browsing this forum: No registered users and 2 guests