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Newb ETX 90 Questions

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#1 Mxplx2

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Posted 02 August 2013 - 07:58 AM


I’ve been looking at the ETX 90, and it looks like a good compromise between portability, magnification and price. So I have a few questions.

1. Can it be conveniently used for quick looks without going through an alignment? I’m talking about either being manually positioned with power off, or positioned using the buttons with power on.

2. What power EP’s should I get to take full advantage of its capabilities.

#2 jgraham

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Posted 02 August 2013 - 09:17 AM

1. Yes, but the mount is a bit stiff to move manually. For quickie views of the moon I used to rough in it manually, then use the motors to tweak it with the hand controller. (You can turn on the hand controller and skip the alignment.) A good Plan-B is to do a good job calibrating the motors, training the drives, and aligning the mount. When you are finished observing use the park function. The next time you set up start with the telescope in the home position and the GoTos will be roughly correct and the tracking will be good enough for visual observing. To align the scope you don't need to god through the full alignment, just synch it on a guide star and you're good to go. In some cases I haven't done a full alignment of my Autostar scopes in over a year, and when I do it is because I forgot to park the scope before turning it off.

2. The usual set; eyepieces in the 6-32mm range with a good 2x barlow. I don't know what a good modern wide field 1.25" eyepiece is, but I like my trusty old Meade RG 20mm Erfle.

#3 Geo.

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Posted 02 August 2013 - 06:03 PM

When the ETX was first introduced the Autostar was an option and the mount was controlled by the EC (electronic controller). The EC would drive the RA at the sidereal rate and had four selectable slew rates. It permitted NSEW correction switches. They often sell for under $20 used.

#4 redlinedb16a

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Posted 02 August 2013 - 08:40 PM

Here's what you do

Unscrew 4 screws

Presto the ota comes off

Onto a cheap camera tripod
I do it all the time,super fast and portable
Posted Image

#5 Mxplx2

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Posted 03 August 2013 - 09:34 AM

Here's what you do

Unscrew 4 screws

Presto the ota comes off

Onto a cheap camera tripod
I do it all the time,super fast and portable
Posted Image


And a Bud Lite in the star light. I love it.

#6 Hitech

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Posted 06 August 2013 - 07:29 AM

When I had mine I limited EP choice to 12mm. It was a good compromise for detail and FOV. 9mm started pushing limits of good resolution and this is using both orthoscopic or Meade 4000 Plossl. I used mine in manual mode lots of times for a quick gaze at the heavens. However I never drank beer when star gazing--- telescope optics themselves present enough hurdles to overcome for good viewing without the need to induce double vision!






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