Re: Kilian's Mirror: Tester is working now.

Bob Madden (madden@netcom.com)
Wed, 19 Apr 1995 15:59:22 -0700 (PDT)

I'll bet my question will explain why Alan's LED didn't work well for him. Alan can you describe th size of the slit you were using with the LED? Or was it a very small hole? Perhaps the reason it didn't work well for you was the fact that you were using too small of a slit. Something I feel a Slitless Tester would solve (that is let enough light get to the mirror).

Bob

):-{])) <---- madden@netcom.com madden@svpal.org Remember amateur astronomers: "keep looking for the next Universe"

On Wed, 19 Apr 1995 kilian@ironwood-fddi.cray.com wrote:

>
> Thanks for all the suggestions about how to use an LED, but it just
> didn't work out for me.
>
> I tried two more LEDs last night, a 5000 mCd Jumbo red LED from the
> Shack of Radios, and a regular O'l green LED.
>
> I lit them both up until they were ready to burst into flames, but I
> couldn't get enough light out of them to get good contrast.
>
> So I used the old Christmas tree tiny bulb on 5 Vdc and a piece of
> plastic from an old checkbook cover to diffuse the lamp.
>
> Next time I'll use a MiniMag light, and two 1.5 Volt batteries like
> someone suggested.
>
> I use a slit width of 0.002 Inches set with an automotive feeler guage
> and I now get swell images.
>
> My mirror read almost spherical using the new tester. There was NO
> difference between the center, and zone #2 (Next out from center)
>
> This is a radical departure from what I was reading when my slit and edge
> were 10 Inches apart.
>
> So I did two turns with a humongous long stroke concentrating on
> the area where the mirror is about to fall off the left and right
> overhangs, and I got more difference on the two center zones.
>
> More measurements tonight, and I'll let you know.
>
> I also fixed a bug in the Texereau program that was created when I
> converted from BASIC to C. Look out, they use tha variable K as an integer
> and a float.
>
> -Alan Kilian
>