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Posts Made By: Larry Beach

March 20, 2014 05:49 AM Forum: Maksutovs

Re: C-90 comparisons

Posted By Larry Beach

Hi Billy, great to hear from you again.
The optics of the C90 have always been good.
The main advantages of the new C90 is the focuser, and
Modern coatings. The old system used a helical system that had the whole top part of the
C90 screw in and out for focus, Those can get very stiff in Cold weather.
Plus the grease in those are all drying out now.
If you want to replace the grease there is a hidden screw under the tripod mount that acts as a stop, and has to be removed. White lithium grease works well and stays fairly smooth. Doing this can also help with collimation from the tube sagging.
The old grease should be cleaned out with a petrol base cleaner, followed by an Orange oil
wipe.
The old coatings are close to 30 years old and are getting tired. A great number of the early C90's do not have Multi Coatings on the Meniscus.
There are rumors the newer optics are a bit better and collimation is better.
I hope this helps.
Larry Duane

March 20, 2014 05:54 AM Forum: Reflectors

Meade Starfinder Mirrors

Posted By Larry Beach

Looking for comments on the Meade Starfinder Mirrors. Have they been tested?
I had a 10" F4.5 I thought the figure was very good. I have an 8" F6 that
I plan to turn into a Dob for a free checkout Telescope for our new Astro club.
I am looking at a 12.5" Are the larger mirrors as good?

May 8, 2018 05:24 AM Forum: AstroMart FAQ

Don't like the Advertisements No prices shown

Posted By Larry Beach

Those of us that shop by price have to open every ad to see if the items are in our price range. A waste of time.. Going to Cloudy Nights where Ads are open and FREE.. see ya and dont bother with me paying for another wasted year here

May 8, 2018 05:44 AM Forum: AstroMart FAQ

Don't like the Advertisements No prices shown

Posted By Larry Beach

Ok how to choose a type of scope or misc and log in and show the items with price wanted and or sold again.