Konus CG-5 mount and setting circles

Hello everybody. I have had my 1st generation (pre-2004) Konus 1793 8" reflector for over 2 years now, and am quite embarassed to say that I've never bothered to learn how to use my setting circles. I am now in the process of attempting to use them to locate objects for the first time, and was hoping that someone with a similar scope or mount could help me.

1. The RA setting circle has two moving rings. The first main ring with the numbers 1-24 has a thumb screw that locks it in place. When you adjust the RA axis, if this thumbscrew is tightened down, this ring doesn't spin.

2. The second RA ring that's inside the main ring does spin however, and can be moved by hand.

Can someone explain to me why there is a lock thumbscew that holds the 1st ring? Any other info that anyone can give me for this particular mount would be great.

Thanks,

James

I've only played with setting circles for a few hours some months ago, so take this with a grain of salt:

I'd bet that the locking ring tracks with the scope. In that was, it stays aligned with the stars. The second ring shows the position of the telescope relative to the stars.

So, I'd guess you aim at a known object and adjust the two rings until the 0/24 on one ring matches the RA of the object on the other ring. Then, lock the locking ring and don't touch the other. As you move the scope, the indicated RA should match the telescope's position.

Allen