Re: Ronchi testing. How I did it?
Bob Madden (madden@netcom.com)
Tue, 18 Apr 1995 08:30:22 -0700 (PDT)
I fab'd a Ronchi tower in the following manner:
Use a frosted LED and the necessary power supply (including a rheostat).
immediately, about 1/8-1/4, place the Ronchi screen, 133 lines/ionch -
purchased from Willimann-Bell, between the light - your eye and the mirror.
I like to start just before the radius of curvature and slowly move
rearward until about 1/8 infront of the radius of curvature. The spaced
dark bands should be wide enough to be easily seen. Moving in and away
from this point will change the size of the pands. When _AT_ the RC the
band will be so large it will be difficult to discern. Use the program to
get an idea of what the bands should look like. You can also tip the
tower slightlu to move the bands accross the mirror image.
If I can figure how to up load, I can send to Robert's site a simple sketch
showing my crude lash-up. I'll work on UUencoding a file. Don't count on
my Inet skills though.
Bob
):-{])) <---- madden@netcom.com
madden@svpal.org
Remember amateur astronomers:
"keep looking for the next Universe"