Subject: DIY Solar Telrad

Posted on: October 06 2011 @ 01:48 am
By: nspace01

Content:

NEVER VIEW THE SUN WITHOUT A SOLAR FILTER ON YOUR TELESCOPE!!!!

NEVER USE THE SMALL GLASS SOLAR FILTERS THAT SCREW TO THE EYEPIECE!!!!!

BOTH OF THESE METHODS WILL BLIND YOU IN ONE EYE!!! ( PROBIBLY GET THE OTHER EYE TOO, IF YOUR REALLY DUMB!!!)


"Idle Hands make Idle Minds"


Here is my latest DIY Astro project:

I recently ordered the material and made two Baadar Solar Film Filters for two of my scopes, a 6" MAK and a 10" S/N DOB.

The filters work well beyond any solar filters I have ever used. (Anybody that wants info on what to get and how to contruct the filters, let me know)

The only small problem was getting the solar disc in the eyepiece. It is hard to find the sun with a completely black field...Just move the scope around till you find it, or make the smallest shadow of the scope on the ground.

Solution:

I had a very old non-working Telrad ( probibly had a burned out retical).

I pulled out all the electronics

I printed out "Bulls-eye", laminated it and cut it to the same size as the telrad reflector glass.

I placed the Bulls-eye ontop of the glass and slipped back into the slot on the head of the telrad.

I took an old black plastic CD case and cut a oblong oval about 3" long, 2" wide. I drilled a 1/8" hole , 1/2" from one edge of the oval
and a 3/8" slot from the center to the other oval edge. I call this the "Retical Oval"

At the other end of the telrad I center drilled a 1/4" hole to mount the retical oval.

I then attached retical oval at the center of the slot, (with the 1/8" hole at the top.) with a 1/2" x 20 screw and nut.

Done!!

Calibrate the solar filter as follows: (make sure the sun is out!!!)

Set up your scope with a solar filter attached.

Mount the Solar Telrad on your exiting (sic) Telrad Base.

Locate and center the sun in your telecope eyepiece by any means nessesary.

Slightly loosen the screw at the frount end of the Solar Telrad and slide the retical oval up and down, left and right until the little dot of sunlight from the 1/8" hole, in the retical oval, falls on the center of the Bulls-eye on the reflector glass. Retighten the screw/nut to snugly hold the retical oval in place.

To use the Solar Telrad, simply point the scope in the general direction of the sun....Move the scope until the little sunlight dot is centered on the Bulls-eye and you are ready to view the sun. (You can view the bulls-eye from either side of the glass reflector.)

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/4846410/page/0/view/collapsed/sb/5/o/all/fpart/1#Post4847378



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