MnAstro Forums

I have a 13" Dobsonian and a Telrad. Any tips on lining it up. Right now the telrad is just sitting on the table next to the scope.

Hi Jessi,

If I understand your question properly, you are trying to line up the telrad with your main scope?

The easiest way to do it at night is to use the Moon. It's a big bright object that you can easily find in your telescope without the finder. Once it's centered in the eyepiece you can adjust the three knobs on the front of the telrad to maneuver the red telrad circles so that the Moon is also centered.

If there's no Moon available, just take the scope out during the day and find a far away tree branch, roof or window and do the same.

I hope this helps!

Suresh

Thanks! I'll give that a try. But first I need to actually attach the base to the scope.

The adhesive is kind of intimidating...I feel like there's no room for error.

Don't be intimidated. It's easy, and even if you get it totally crooked you can get it back off by sawing through the foam tape with a piece of dental floss, then rubbing the rest of it off with your thumb. More tape is available at hardware stores or Menards and elsewhere.

But to get it straight, what I do is tape a piece of string along the length of the optical tube assembly all the way from front to back, right next to where you want to mount the Telrad. That way you can use it as a guide in lining it up. When you've got it lined up, just press it down and it's mounted.

When aligning the Telrad, just like any finder scope, be sure to first sight on something distant with the scope then adjust the knobs on the Telrad to sight it in on what the scope is seeing. Very difficult the other way around!

Thank you for replying! I will definitely try the dental floss trick. I feel a little more confident about installing it now.