10 replies to this topic

[Whalensdad]

I just inherited a mid 80's (or there about) Meade 8 inch SCT OTA. It looks to have been kept in good condition. Only some slight dust on the mirror and the corrector plate. There are some spots on the secondary. It does not have a dovetail. The only markings on the OTA, other than on the corrector plate ring, are "Multi-Coated/Silvered Optics Group".

 

Are there any special precautions to cleaning the secondary? (alignment, removal, etc.)

Is there are way to identify the model of the SCT?

In general, how were SCTs of this generation optically?

Is it easy to add a dovetail to this OTA?

 

 

Attached Thumbnails

• 
• 

[MisterDan]

You have the 2080 LX3.

It was introduced in 1985.

 

The primary was not silvered.  Only the secondary was.

 

Best wishes.

Dan

Edited by MisterDan, 20 June 2025 - 04:40 PM.

[Augustus]

You can pry the secondary out and send it off to a recoating place then silicone it back in. The tarnish presently is probably pretty bad for performance

[quilty]

I think it might be a good one.

Specs on the silvered mirror might be a problem. When they cover a considerable part of the mirror it should be recoated while small spots of less than 5% area are neglible.
Dovetail is quite simple to attach. Best use 4 screws from the existing ones at the front and rear cell.
Replace them by longer ones and attach an aftermarket Vixen rail. I have a DIY one folded out of a 4 mm thick aluminium tin then attached by 4 longer (by 4 mm) replacement screws.

[VA3DSO]

Yes, 1985 - 1987 Meade 2080 LX3. The silvered optic is just the small secondary mirror and they are known to tarnish (black spots). I have one, and I sent out my secondary to get re-coated - I didn't even have to remove the mirror from the aluminium backing - the coater (Optiques Fullum in Quebec) took care of everything for me. It cost me about $120 Canadian to get it done. 

 

It is very easy to add a dovetail - I bought a Farpoint Astro one and it bolted directly to my OTA:

 

https://farpointastr...eade-8-inch-sct

 

If you do any disassembly of the optics, make sure you mark the orientation of the corrector plate in relation to the OTA as well as the orientation of the secondary to the corrector plate - you want to ensure it all gets reassembled the same way (rotation) that it came apart. I'm not aware that you can recondition the secondary yourself - but may others have tried that and will chime in?

 

As for optical quality - it may be hit or miss. This scope was made during the Halley's Comet craze of the 1980's and during that time Meade and Celestron cranked up production and quality slipped. The only way to know for sure is to do a star test.

 

I hope that helps! Let us know if you have more questions.

 

OH! Here's a link to the manual for your scope....

 

https://deepskies.co...080-2120man.pdf

 

Clear skies!

Rick

 

PS: here are my "before" and "after" pics of getting my secondary re-coated...

 

 

[Whalensdad]

You have the 2080 LX3.

It was introduced in 1985.

 

The primary was not silvered.  Only the secondary was.

 

Best wishes.

Dan

Thanks for the quick response.

 

I think it might be a good one.

Specs on the silvered mirror might be a problem. When they cover a considerable part of the mirror it should be recoated while small spots of less than 5% area are neglible.
Dovetail is quite simple to attach. Best use 4 screws from the existing ones at the front and rear cell.
Replace them by longer ones and attach an aftermarket Vixen rail. I have a DIY one folded out of a 4 mm thick aluminium tin then attached by 4 longer (by 4 mm) replacement screws.

Are there any instructions on removing the secondary? Prying it out does not seem to be the best method. Any recommendations on where to send it to be recoated? 

[Whalensdad]

Yes, 1985 - 1987 Meade 2080 LX3. The silvered optic is just the small secondary mirror and they are known to tarnish (black spots). I have one, and I sent out my secondary to get re-coated - I didn't even have to remove the mirror from the aluminium backing - the coater (Optiques Fullum in Quebec) took care of everything for me. It cost me about $120 Canadian to get it done. 

 

It is very easy to add a dovetail - I bought a Farpoint Astro one and it bolted directly to my OTA:

 

https://farpointastr...eade-8-inch-sct

 

If you do any disassembly of the optics, make sure you mark the orientation of the corrector plate in relation to the OTA as well as the orientation of the secondary to the corrector plate - you want to ensure it all gets reassembled the same way (rotation) that it came apart. I'm not aware that you can recondition the secondary yourself - but may others have tried that and will chime in?

 

As for optical quality - it may be hit or miss. This scope was made during the Halley's Comet craze of the 1980's and during that time Meade and Celestron cranked up production and quality slipped. The only way to know for sure is to do a star test.

 

I hope that helps! Let us know if you have more questions.

 

OH! Here's a link to the manual for your scope....

 

https://deepskies.co...080-2120man.pdf

 

Clear skies!

Rick

 

PS: here are my "before" and "after" pics of getting my secondary re-coated...

 

Thank you for the detailed info. Can you point me to any steps on removing the secinday?

[VA3DSO]

Thanks for the quick response.

 

Are there any instructions on removing the secondary? Prying it out does not seem to be the best method. Any recommendations on where to send it to be recoated? 

Removing the secondary involves:

• removing the corrector plate by removing the six Allen bolts holding it in place - use a piece of masking tape or something similar to mark it so it can go back in to the cell in the same orientation
• then, undoing the three smaller Allen bolts holding the secondary on to the corrector (also used for collimation) - again make sure you note the orientation so you can put the secondary back in the same way it came out

I'm in Canada so I used Optiques Fullum, but I'm sure there's a few US places that do this kind of work.

 

You might want to try the scope out first before deciding to get it re-coated.

[VA3DSO]

Thank you for the detailed info. Can you point me to any steps on removing the secinday?

Ah! I responded too quickly. See my post above.

 

For additional info, I'd try this search in Google:

 

how to remove secondary mirror from Meade 2080 SCT

Edited by VA3DSO, 20 June 2025 - 05:09 PM.

[Don W]

Silly me. I was just going to mention that Meade had a lifetime warranty on much of their stuff. 
 

Not much good when they’re out of business!

[Whalensdad]

Silly me. I was just going to mention that Meade had a lifetime warranty on much of their stuff. 
 

Not much good when they’re out of business!

I was talking to a friend last night. He has an 8inch LX3. about 3 years ago he sent it in to Meade for recoating of the secondary. They gave him the option of having it upgraded to an ACF corrector plate for $750. That brought the scope down to f/8 or something.

 

Not sure what is going to cost to get the secondary recoated. Have only found a few merchants:

https://clausing.com/
https://www.ostahowskioptics.com/

https://www.majestic-coatings.com/

https://www.spectrum...ings.com/prices

 

What size is the secondary in the LX3?

Edited by Whalensdad, 21 June 2025 - 02:08 PM.