etx 90 slipping secondary

[cyclingasronomer]

i have an etx 90 from 7 or 8 years ago. i recently went to use it after a year or two, and found that the secondary has slipped from the centre of the front lense. since it is not any longer under warranty, is it safe for me to take it to my local (knowledgable) telescope store here in vancouver canada to be fixed, or is it necessary to send it back to meade? thank you for a reply.

[seeker372011]

This place may be worth checking out as another alternative

http://www.weasner.com/etx/techtips/tuneup...up_service.html


(i have no personal first hand experience with this though)

[Padawan]

cyclingastronomer,

I have had the exact same problem. Thanks for bringing it up, now atleast there is hope that my scope will be fixed. But this experience has taught me to not let a telescope with that design rest its main tube horizontally for long.

[Gneiss]

cyclingastronomer,

I have had the exact same problem. Thanks for bringing it up, now atleast there is hope that my scope will be fixed. But this experience has taught me to not let a telescope with that design rest its main tube horizontally for long.

But that's how they come in it the box - it's a bit of a worry if you can't store it like that...

I can't say it's a problem I have come across before.

[SarahMc]

Your best bet is to send it back to Meade for repair. There's been a number of ETX scopes that have had this problem. The secondary is mounted to the corrector with a glue-like substance, and in high heat conditions (and possibly some poor assembly procedures) the glue softens and the secondary slips.

The secondary is aligned to the corrector and primary during assembly using a special optical jig at Meades factory. Someone else may get close to the proper position, but I would think that only the Meade factory can do it correctly.

I had a similar problem with my ETX125, but it was under warranty. It took about a four week turnaround time. The good thing about having Meade do it, is that they also check out the rest of the scope while it's there.

You also may want to check out Mike Weasner's site (link is in a post above) and see if this is a common occurance with ETX90's. If so, maybe Meade will do the repair for free (other than shipping charges).

Once repaired, take some precautions. Store the scope with the corrector down, facing the base. Don't leave the scope in a hot car or trunk, and only use a solar filter that fits over the corrector (never use an eyepiece type solar filter under any conditions or telescope). Don't leave the scope out in the sun uncovered at star parties. Take it down or cover it with a breathable fabric, like a sheet.

[Padawan]

But that's how they come in it the box - it's a bit of a worry if you can't store it like that...

I can't say it's a problem I have come across before.

It is certainly worrying. I wonder if other Meade scopes with a similar design have had this problem.