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SteveDallas · 06-10-2003, 05:01 PM

Thanks!

I have one telescope with no tracking at all. It's a 4.25" f/5 Dobsonian that I made, theoretically as practice for a larger scope. I'm not sorry I did it, but it was very frustrating due to my lack of mechanical aptitude. I practically never use it.

Then I have the Meade ETX-70. It sits level and just moves up and down and side to side. It has a hand-held computer attached to it that, if properly set up, will automatically track whatever you point it to. Being able to do this is real time is non-trivial from a mathematical standpoint, but of course these days you get it in a package the size of a TV remote control.

My new addition is the ETX-90RA. It is an older, discontinued model. It doesn't have any "brains" like the ETX-70, it just rotates theoretically once every 24 hours. So if you line it up with the axis of rotation pointing at the north celestial pole, it will stay on whatever you point it at.

I guess it depends on what you want to do... in my case I wasnted womething that was better for planetary viewing, and I didn't need the computer gizmo to find planets, so I saved about $200 by getting the older version (which has the same optics as the current ETX-90 with computer control). What were you what to do with the barndoor mount? I've never used one, but they seem easy enough to build & use.

06-10-2003, 05:01 PM	#5
SteveDallas Your Bartender Join Date: Jan 2002 Location: Philly Burbs, PA Posts: 7,651	Thanks! I have one telescope with no tracking at all. It's a 4.25" f/5 Dobsonian that I made, theoretically as practice for a larger scope. I'm not sorry I did it, but it was very frustrating due to my lack of mechanical aptitude. I practically never use it. Then I have the Meade ETX-70. It sits level and just moves up and down and side to side. It has a hand-held computer attached to it that, if properly set up, will automatically track whatever you point it to. Being able to do this is real time is non-trivial from a mathematical standpoint, but of course these days you get it in a package the size of a TV remote control. My new addition is the ETX-90RA. It is an older, discontinued model. It doesn't have any "brains" like the ETX-70, it just rotates theoretically once every 24 hours. So if you line it up with the axis of rotation pointing at the north celestial pole, it will stay on whatever you point it at. I guess it depends on what you want to do... in my case I wasnted womething that was better for planetary viewing, and I didn't need the computer gizmo to find planets, so I saved about $200 by getting the older version (which has the same optics as the current ETX-90 with computer control). What were you what to do with the barndoor mount? I've never used one, but they seem easy enough to build & use. Last edited by SteveDallas; 06-10-2003 at 05:16 PM.