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PostPosted: Wed Oct 23, 2013 4:27 pm 
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molecule
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I was working on getting my secondary mirror and spider reinstalled when the cat decided it would look better on the floor. The good news is that when I did the flashlight test a lot of light was showing through, so it needed a re-coating anyways.

So now I need a 2.14" secondary mirror but all I can find are overpriced $125+ (And the more expensive quartz mirrors that aren't overpriced, just out of my budget) units online.

Anybody have a better source?

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Last edited by Turd on Wed Oct 23, 2013 4:45 pm, edited 1 time in total.

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PostPosted: Wed Oct 23, 2013 4:35 pm 
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molecule
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To clarify, I think the original secondary mirror was something like 2.28" but general opinion seems to be that for the 8" F4.9 Newtonian a 2.14" mirror is enough to still achieve a fully illuminated field.

RIP Synta secondary mirror, Dec 2004-Oct 2013.

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PostPosted: Wed Oct 23, 2013 5:05 pm 
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Antares

Meridian

Destiny



So, I gave you links to three options in different value ranges...all under $100. If it was me I would spend the extra on a Protostar, but then I want max PTV for those rare nights where I can push magnification on planets. You may not need such high tolerances for AP, where merely hitting the diffraction limit will do the job. I know Antares has a solid reputation for secondaries. I don't know who sources the mirrors for Meridian or Destiny but I imagine they must be true 1/4 wave at a minimum.

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PostPosted: Wed Oct 23, 2013 9:23 pm 
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molecule
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Thanks, I was looking at destiny a bit ago. Looks like one of the lower quality Antares mirrors will be on the way to me.

I fully intend to pick up a Protostar quartz secondary in the future... Around the same time I replace my primary with a Swayze or Royce offering. Just have to wait and see who has the best deal when I feel like dropping the cash.

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PostPosted: Thu Oct 24, 2013 10:43 am 
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I've ordered a few things from Meridian in the past and the quality was always good. Their prices are dirt cheap!

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PostPosted: Thu Oct 24, 2013 10:43 am 
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I've ordered a few things from Meridian in the past and the quality was always good. Their prices are dirt cheap!

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Homebuilt 16" Truss Dob
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SV 80mm ED Nighthawk NG on M1 ALT/AZ
Nikon Prostaff 65mm spotter on Trekpod
Konusvue 20x80 binos/Peterson PipeMount


"Newt Gingrich is what stupid people think smart people sound like."
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PostPosted: Thu Oct 24, 2013 11:22 am 
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Hey Erik...have you ordered a few things from Meridian in the past, and was the quality always good? And are their prices dirt cheap?

:cheesygrin:

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PostPosted: Thu Oct 24, 2013 11:29 am 
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PostPosted: Thu Oct 24, 2013 10:22 pm 
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:lol: My hands must be shaky. Need to stop hittin' the bottle I guess... :grin:

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PostPosted: Fri Oct 25, 2013 8:00 am 
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:lol:

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PostPosted: Mon Oct 28, 2013 1:19 pm 
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molecule
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Try Astrosystems.biz for Ostahowski secondary mirrors.
Try Antares optical for excellent secondaries
Try Protostar for quartz secondaries (their Pyrex secondaries are a little pricey).
You can get cheaper secondaries from GSO, but caveat emptor.

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