I have computer controlled mounts (Nexstar 8SE and a 127mm F6.8 achro on an AVX) but I don't want to depend on them. Both of those mounts are heavy and take a good 20-30 minutes get out of the workshop, set-up, aligned, and finally pointing somewhere interesting. I sometimes want to just take a small grab-n-go, plunk it down in the yard and look at two or three things and then put everything away. So, to do that I have an early 80's era Celestron C90 Mak Astro with a wedge.
So, I understand setting circles and how to use them...in theory. I haven't been able to find anything with them so far which suggests that my polar alignment, particularly the wedge angle is incorrect. So, hopefully someone can show me where I have boneheaded the wedge set-up. My procedure thus far is:
- With the mount and scope removed from the wedge, I level the OTA with bubble level and ensure the azimuth gauge is set to 0.
- Place the mount on the wedge, raise the elevation, now declination, so it reads my latitude 33 degrees.
- Adjust the wedge so that a bubble level resting on the lens cap becomes level...that should put the wedge at 57 degrees, right?
Something is wrong, because setting the RA dial to current sidereal time and slewing to targets doesn't work, nor does centering a known bright star in a high magnification eyepiece and setting the RA to that works...the Dec is usually fairly wrong as well. That tells me the wedge is wrong or I am missing a step. Any advice would be appreciated. The mount is aligned to Polaris or as close as I can get it.
Also, maybe I'm reading getting the celestial coordinate pairs incorrect. I am using Stellarium and selecting a star, and reading RA/DE (of date) coordinates. For example, Vega is 18h37m38s/+38 48' 15"...but there is also the Hour angle/DE which is 21h54m35s (changing)/38 48' 15". I've tried both to no avail. Is there a time adjustment I need to account for?