henrylr
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Posts posted by henrylr
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Thanks again. I'm 75 years old and don't do much viewing but thought it would be a fun diversion to improve the old Meade. Robert Royce has retired.
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Thanks for the reply. I recently sold my custom made 10" newt. It had excellent mirrors. So that is why I want to improve the optics in the Meade. My other concern is the surface quality of 40-60 for A/8 mirrors available. Another question I have is would you know where I could get a good 4.5" parabolic mirror. The ones from china don't provide any info like strehl ratio and wavefront RMS.
Thanks,
henrylr
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I'm trying to improve the performance of my Meade 4500 and have sent emails to some makers asking for spec.s of their 4.5" primaries. While waiting for replies I started thinking about the secondary. I imagine the stock secondary is, at best, an A/8. So would replacing the secondary with an A/30 secondary result in a visible improvement? The calculation, for a secondary minimum minor dia., result is 1.13" I did check out Edmunds and they have a perfect size for the meade but it is A/8 and the surface quality is only 40-60 which is considered a low quality rating and will likely produce some scattered light. The smallest A/30 secondaries have a minor of 1.3". Would that work or would it block to much light?
Thanks,
henrylr
Improving a Meade 4500 question
in Discussions - Scopes / Whole setups
Posted
Seems almost all of the 4.5" mirrors are spherical and are made in China. Now I don't want to buy a pig in a poke so I sent emails to several Chinese makers/sellers asking for strehl ratio and wavefront spec.s. Replies were all the same..."do not have those specifications". Now the mirrors I inquired about were not cheap, selling for $100 to $150. It strikes me as odd that folks would spend that much without any spec.s.