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Re: (ATM) secondary-holder/spiders
- To: atm@efn.org
- Subject: Re: (ATM) secondary-holder/spiders
- From: Chuck Grant <grant@aretha.llnl.gov>
- Date: Fri, 13 Oct 1995 16:55:46 -0700
- Bell-Net: (510) 422-7278 (Fax 510 422-2095)
- Campus: Lawrence Livermore National Laboratory
- Department: Environmental Protection Department
- Division: Environmental Restoration Division
- In-Reply-To: <Pine.BSD/.3.91.951013105430.16636A-100000@bud.indirect.com>(message from Frank Honer on Fri, 13 Oct 1995 11:01:09 -0700 (MST))
- Location: 7000 East Ave. L-530, Livermore, California, USA 94550
- Organization: University of California
- Reply-To: chuck-grant@llnl.gov
In affixing the diagonal mirror to the holder you must balance
leaving it loose enough so that there are no visible effects
from stress, with or without thermal expansion, and mounting
it firm enough that the collimation does not change as you
orient the telescope in different directions.
If it is firm enough not to move, you don't have to worry
about it falling off (under normal conditions).
Chuck
PS. I have heard that "second" mirror in a Newtonian is
properly called a "diagonal mirror" and that the term
"secondary mirror" is supposed to be used only when the
mirror is not flat, ie. as in a Cassegrain. Does anyone
know for sure? Please no opinions, only respond if you
know for sure. A reference would be nice.