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Messages 839 - 868 of 1382   Oldest  |  < Older  |  Newer >  |  Newest
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839
I hope you all have another great year chasing ancient photons! -Christopher Erickson...
Christopher Erickson
data_plumber1
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Jan 2, 2006
7:46 pm
840
Thanks, I'm hoping for a better year than last. (I sort of sit and wait for those photons to come to me) ... __________________________________ Yahoo! for Good...
Larry
DocCPU
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Jan 2, 2006
8:35 pm
841
Hello all, For those of you who are swayed by popularly-touted brand names :-), the builder of my telescope is advertising that he has the opportunity to get a...
astronomer_c
Online Now Send Email
Jan 21, 2006
2:02 am
842
Hi, first post from a new member. I haven't had a scope since I was a kiddo, and it was a typical department-store refractor with poor optics. As an adult,...
Jim
d3zapped
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Jan 30, 2006
8:18 pm
843
d3zapped - re the older Meade 8 inch Newt: The $200 price seems at least reasonable to me. An 8 inch Newt on a decent GEM would make a fine beginning scope....
mhholl@...
m_hollimon
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Jan 30, 2006
9:24 pm
844
Clock motors are very nice when you are trying to observe objects at higher magnifications. I wouldn't disable it unless it was defective and unrepairable. ...
Christopher Erickson
data_plumber1
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Jan 30, 2006
10:03 pm
845
Mick H., thanks for your clear explanation of abberations that commonly affect fast optics. Also the suggestion to carefully inspect the main mirror - aside...
Jim
d3zapped
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Jan 31, 2006
1:14 am
846
Insertions below... <SNIP> ... Scopes from this era had clutches on the drives that allowed the scope to be pushed around and still have the RA motor running...
Christopher Erickson
data_plumber1
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Jan 31, 2006
4:31 am
847
Dear Jim, Date: Tue, 31 Jan 2006 01:00:32 -0000 From: "Jim" <d3zapped@...> Subject: Thanks & more questions (of course :) Also, does an RA drive motor...
Wayne G
missyy9
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Feb 2, 2006
1:04 am
848
On 2/1/06 fomalhaut@... wrote: ........and the 60-cycle power grid you plug into every day is one of the best frequency-regulated sinusoidal power...
mhholl@...
m_hollimon
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Feb 2, 2006
2:30 am
849
... Um, no they don't. -Christopher Erickson, Electrical Engineer...
Christopher Erickson
data_plumber1
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Feb 2, 2006
5:23 am
850
... Um, no they don't. -Christopher Erickson, Electrical Engineer Very odd, since a PG&E engineer once told me that PGE did do that. How else to keep electric...
mhholl@...
m_hollimon
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Feb 2, 2006
6:36 am
851
In a message dated 2/2/2006 7:54:04 AM Pacific Standard Time, NewtonianReflector@yahoogroups.com writes: The power utility counts the number of 60 Hz cycles in...
catboat15@...
olewilly2000
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Feb 4, 2006
6:21 am
852
The North American Electrical Grid requires sinusoidal synchronization accuracy of one microsecond and is a non-trivial process. This is required because the...
Christopher Erickson
data_plumber1
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Feb 5, 2006
5:29 am
853
Date: Sat, 04 Feb 2006 20:25:33 -0900 From: Christopher Erickson <cerickson@...> Subject: RE: Digest Number 310 The North American Electrical Grid requires...
Wayne G
missyy9
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Feb 5, 2006
5:27 pm
854
In a message dated 2/5/2006 4:23:48 AM Pacific Standard Time, NewtonianReflector@yahoogroups.com writes: Anywhere from 50hz to 70hz might have been good...
catboat15@...
olewilly2000
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Feb 6, 2006
5:25 am
855
Heh. I ain't all that young myself but I think you have a few years on me! That is some cool history and feel free to share more any time the urge strikes you....
Christopher Erickson
data_plumber1
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Feb 6, 2006
6:13 am
856
When I finally went to check out the scope, it was a crisp dark night here in Central Texas. It produced pristine images, at least to my inexperienced eyes,...
Jim
d3zapped
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Feb 6, 2006
10:03 am
857
Definitely not an f/4.6. Looks like an f/6 to me. Should make it easier to collimate, and will give you a larger aberration-free area at the centre of the...
Thomas Teague
bty308391
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Feb 6, 2006
10:26 am
858
The 40mm eyepiece is a 'modified achromat' Not sure what that is, but I'd guess it's probably a superior kind of Kellner. The others ('wide angle') may be of...
Thomas Teague
bty308391
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Feb 6, 2006
10:40 am
859
Group - an earlier post of mine contained a statement that power utilities counted cycles of the 60 Hz line and corrected in the middle of the night to keep...
mhholl@...
m_hollimon
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Feb 6, 2006
7:12 pm
860
As long as we take the term "absolute frequency" to only be true for a given frame of reference, lest we disturb Einstein's sleep. ... ...
Larry
DocCPU
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Feb 6, 2006
7:25 pm
861
And I don't think it is really a big deal as it applies to the original telescope-drive related question. 1. The frequency of the grid is certainly accurate...
Christopher Erickson
data_plumber1
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Feb 7, 2006
7:14 pm
862
... original telescope-drive related question. 1. The frequency of the grid is certainly accurate enough for any telescope drive around. 2. The frequency of...
mhholl@...
m_hollimon
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Feb 7, 2006
9:18 pm
863
In the telecommunications industry we now use GPS signals for everything that needs a precise clock reference. Even going back 40 years I don't think we ever...
Christopher Erickson
data_plumber1
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Feb 8, 2006
12:04 am
864
I have to agree with all of that. Usually what moves a scope off is alignment problems, not the error in the 60 HZ clock. (Personally, I suspect that the...
Larry
DocCPU
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Feb 8, 2006
1:48 am
865
... everything that needs a precise clock reference. Even going back 40 years I don't think we ever used the power line for an accurate clock reference. We...
mhholl@...
m_hollimon
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Feb 8, 2006
9:14 pm
866
In a message dated 2/9/2006 8:24:19 AM Pacific Standard Time, NewtonianReflector@yahoogroups.com writes: It's a different world now. It sure is! Programs I...
catboat15@...
olewilly2000
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Feb 9, 2006
4:53 pm
867
Date: Wed, 8 Feb 2006 16:13:38 EST From: mhholl@... Subject: Re: Re: Power Line Frequency Considerations Even going back 40 years I don't think we ever used...
Wayne G
missyy9
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Feb 10, 2006
6:37 am
868
Reminds me of the story of the store keeper (years past) that set his clock by the noon whistle every day. One day the man who blew the whistle was in the ...
Larry
DocCPU
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Feb 10, 2006
2:47 pm
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