ATM Foucault woes

[Jeffmight@aol.com]

  I finally finished polishing my 6" f10 mirror and I'm ready to start 
figuring. Last weekend I built a foucault tester. Moving source slitless 
tester. The basic plan was from "Build your own telescope" with the LED 
source and electronics from the Stellafane web site. 
       First initial question - In "Build your own telescope" they have a 
viewing telescope mounted behind the KE, but in the Stellafane plans they 
don't, is one needed? I have mine on a pivot so I can swing it out of the way 
if not needed. The scope is made from the 50mm objective from a finder scope, 
a piece of thin aluminum pipe and a 40mm eyepiece - it focuses from 4 ft. to 
infinity. 
       I'm doing something very wrong here. My first attempt was to find the 
exact focal length of the mirror - where it "grays out" uniformly. All I saw 
was the small green dot of the LED reflected in the mirror. The entire face 
of the mirror was not illuminated as I had expected. Maybe the room lights 
were too bright, so I tried it again in a darkened room and still I got the 
same green dot but not the illuminated mirror. 
       Then I thought maybe the mirror was not pointed directly at the 
tester, so I replaced the viewing telescope with a laser collimator and made 
sure the return beam was parallel. Same view, a green dot.
       I tried removing the viewing telescope and just looking with my eye. 
Same view. Somewhere it said your eye had to be close to the KE so I tried 
moving closer to the KE - 1/2 an inch was as close as I would try without 
risking shaving my cornea off. Same view. 
       Then I thought maybe the LED light was not diffuse enough so I placed 
some cellophane tape in front of the LED. The 1/4 inch green dot ballooned to 
1 inch in diameter on the mirror but the face of the mirror was still not 
illuminated as I expected to see.   
       I've read David Harbour's Understanding Foucault, many times now, and 
it seems pretty starightforward. I at least was hoping to see the KE change 
sides on the green dot to pinpoint the exact focal length but it never did. I 
know the focal length is close to 60 inches from focusing the sun on a wall 
outside. 
      Any ideas where I went wrong? 
                                                             Thanks for any 
help,  Jeff