SCHOTT NARROW-BAND INTERFERENCE FILTERS 300 to 2, 000 rmi. ... Since only a small segment of 90Ad rotation is actually used, the vernier drive of an old radioa#39;s variable capacitor was added to achieve fine control ... Mr. Hereforda#39;s design is shown in the diagram and photographs. ... appear in focus, or reasonably so, when viewed against the sky. ... to reduce scattered light- The spot support can be made of blackened wires instead of the post showrn in the pictures, although weanbsp;...
|Title||:||Sky & Telescope|
|Author||:||Charles Anthony Federer|