StarWars
(Postmaster)
10/04/04 12:42 PM
Dealing with RA Tracking Problems



Dealing with RA Tracking Problems.

http://home.att.net/~jblessin/etxra.htm


seeker372011
(scholastic sledgehammer)
10/10/04 11:08 PM
Re: Dealing with RA Tracking Problems

The link to the Microstar drive corrector page doesnt seem to be working?

StarWars
(Postmaster)
10/11/04 12:00 PM
Re: Dealing with RA Tracking Problems

Quote:

The link to the Microstar drive corrector page doesnt seem to be working?





Here is another link to the Microstar drive corrector page ..


http://www.weasner.com/etx/microstar1.html


Anonymous
(Unregistered)
10/12/04 01:19 PM
Re: Dealing with RA Tracking Problems

I think the existence of this thread might answer my question, but...

I've been struggling over the course of several nights to get my ETX-125EC to track correctly for long-exposure photography. The tracking error seems to be in only one axis, namely, RA. Unfortunately, adjusting the tracking speed with the controller still doesn't create very satisfying results.

Now, I've been spoilt by using professional astro facilities for photography before I got my personal scope, and wanted to see if anyone else had problems with the ETX models having less-than-precise clock drives, or if I was just being picky.


StarWars
(Postmaster)
10/13/04 03:09 AM
Re: Dealing with RA Tracking Problems



Supercharge the ETX-125 ..


http://www.arksky.org/supercharge.htm


Rainbow
(professor emeritus)
04/23/05 01:53 PM
Re: Dealing with RA Tracking Problems

The etx series is not designed for long exposure photography - instead you need to take lots of short shots and use image stacking software.

rogerandgarf
(sage)
08/12/05 01:43 AM
Re: Dealing with RA Tracking Problems

Remember that the autostar has a high-precision setting for tracking,etc.

JAT Observatory
(Got Cookies?)
08/12/05 11:03 PM
Re: Dealing with RA Tracking Problems

The high-precision in the Autostar is not for tracking. It is used to make goto's more accurate by forcing you to align and sync on a bright star near the object you are slewing to.

tom r.
(sage)
08/24/06 03:03 PM
Re: Dealing with RA Tracking Problems

just returned my etx-125 to meade throught their Sky Assurance program. i have had this scope for over a year and a half when tracking and slewing problems started. it has not been a real pleasure dealing with meade. having to wait on hold for an average of about 45 minutes, once as long as an hour and 10 minutes, to get to a service support technician is poor service, IMHO.
tracking was jerky as the object would drift out from the center of view and then snap back to the center with a clicking noise eminating from the drive base. time will only tell how long their turn-around will be in returning the etx. after i receive the etx i plan on sending it our for supercharging and really start enjoying the precision tracking that this scope is capable of.
knowing what i know about meade's after sales support, i will be going elsewhere for that next upgrade (subliminal message ORION).
i think meade should heed my read and others should follow up with either their satisfaction, or dissatisfaction, with meade support.


StarWars
(Postmaster)
11/18/07 07:44 PM
Re: Dealing with RA Tracking Problems




I think the supercharging involves replace factory gear Lubricant with a quality Lithium Lubricant plus optical adjustments..


NoiseJammer
(super member)
02/27/08 08:12 PM
Re: Dealing with RA Tracking Problems

I've stripped my ETX105 several times in an attempt to improve the pointing and tracking. The components are identical. The short version is that unless you plan to confine yourself to shallow space, you probably need to mount the optics on a new mount, and even then it will be hard work.

The drive problem arises from two places... the basic drive mechanism and the time it takes the scope to respond to guiding corrections.

The first problem is (I think) dominated by the worm wheel which is about 38mm diameter - this is way too small to achieve ~2 arcsec tracking which you need for open loop imaging. It's also possible that the gearbox introduces a lot of periodic error - but there is no mechanism for correcting this.

The second problem relates to the control bandwidth. This might be specific to my scope (or how it's set up) but I can't get the delay down to less than several seconds. This is generally not going to help correcting your drive.

A final observation might be useful - you can gain a lot against drive problems by using a focal length reducer. Depending on your chip size, reducing to f/5 _may_ be possible, and f/10 probably is. This will reduce the exposure (9x at f/5, 2x at f/10.)

Clearest
Bruce, Toronto

Modified LX200/12, FLT110, ETX105



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