There was a complete 40 inch at RFO at one time, I was able to observe with
it twice. If I recall correctly it was about an f3.2 and had quite a
problem with astigmatism. At one point they were trying to get an optician
to make a correcting lens for it but I guess that fell through. I think
they said that the rocker box and secondary cage were made with wood from an
old chicken coop.
Dave
-----Original Message-----
From: Evan Garber [mailto:evang@pacbell.net]
Sent: Tuesday, August 31, 2004 10:50 AM
To: The Astronomy Connection
Subject: Re: [TAC] Robert Ferguson Observatory question....
The secondary cage came from another potential Dob of similar dimensions
that was not completed. - perhaps this is the one you are thinking of.
The seeing is impaired by the proximity of the northern bay and by the
fact that the wet evening air funnels up the valley of the moon- at
least this is my theory. I never get the FWHM readings in MaximDl
comparable to those at Lake Sonoma or Lassen.
Best
Evan
Hope to see ou all at Calstar!
Mark Wagner wrote:
> At 8/30/2004, you wrote:
>
>> They were laying out a 40 inch dob that is in the process of being
>> built ( just started the mirror - but have the secondary support
>> completed.
>
>
> Oh! I thought the 40 was operational some time ago. I wonder if it
> is a rebuild.
>
>> The seeing up here is not very good - even up at 2000 feet - and the
>> darkness does not match Lake Sonoma. To the south you get the light
>> dome from Sonoma and to the north from Santa Rosa.
>
>
> Is it usually poor seeing?
>
> Thanks for all the help...
>
> Mark
>
>
>
Received on Tue Aug 31 11:08:22 2004