Diy spectroscope

[p1taylor]

Hi All, Have just finished terminal will I need a light of some sort to see end of fibber optic cable to put star on it, image TERMINAL-1 is what CCD sees with out it connected to scope.

peter

[bojan]

Hmm..
I think you may have a problem with fibre termination (losses at fibre entry and exit).
How did you do it? Did you use lens (it has to be of very high numerical aperture)

[Merlin66]

Peter,
Interesting...
If you use PHD V2.6 (or AA6 slit guiding) you can record and register the position of the fibre in the guide camera FOV.
You can then "nudge" the target star to this X-Y position.
How does the other end of the fibre join to the rest of the spectrograph?
As Bojan indicates there's a fibre f ratio degradation.....a f7 into the fibre comes out at around f5....
(See Astronomical Spectroscopy for Amateurs, p 210)

[p1taylor]

Bojan photo is a shot of pc screen with a shut and click camera,

Ken the other end of the fibre join to the rest of the spectrograph very near to a adjusterbal slit,

I tried the light from a neon test screwdriver down fibber and got a reasonable image.

[Merlin66]

A couple of images of your set-up would help.

[p1taylor]

Hi Ken, Sorry only have a old image we are having a rebuild to get focuser right for CCD but layout is manly the same, when it is finished will post images.

peter