User manual BUSHNELL 78-4502

[. . . ] Coincidentally this star is perfectly north EVERY night you go out. It is generally around 25 to 45 degrees up from the horizon in North America. The second star you will need to be able to identify in the sky is a little bit harder. The second star can really be any star in the sky other than our sun and the North Star. [. . . ] Only in step 2 will you ever turn the telescope here. 3 Fine Adjustment Cables The fine adjustment cables move the declination and right ascension settings in very small increments. When you are aligning the finderscope or centering a star or planet in the telescope there will be a time when only small adjustments will be necessary. That is when you'll use these knobs. Notice one is long and the other is short. It really doesn't matter which one goes on the declination and which one goes on the right ascension. Generally though, they go on just like the below diagram. They connect to the telescope mount only one way so I won't cover their attachment procedure. 898 Declination Fine Adjustment 23 22 21 20 19 18 Right Ascension Fine Adjustment If your equatorial mount is set up correctly, you can move just the Right Ascension Fine Adjustment Knob ONLY to follow any star across the sky! 190-200-210-220-230- 4 Telescope Axis's When using your fine adjustment cables, you'll be moving these two axis's. This instruction manual refers to 3 axis's in which the telescope will turn. This diagram illustrates these axis's where the telescope can move. 5 The Barlow Lens and Eyepieces Here are a few things you'll need to know and know how to do before getting started. You should receive several different lenses for your telescope. Some you'll use a lot and some you'll hardly ever use. The following explains what the pieces are and in what order they should go into the telescope. 3X This the Barlow lens. It multiplies the magnification of the image. Generally it will say something like 2X or 3X on the side of it, meaning that it multiplies the magnification by that much. Sometimes it'll just say "Barlow Lens". Regardless it still does the same thing. There are generally 2 different ones with a new telescope. The eyepiece along with the focal length of the telescope determines the magnification. Most the time they are 20mm and 4mm. The eyepieces can fit directly into the focusing tube as well as into the Barlow Lens. Regardless, you must have an eyepiece in to see anything through the telescope. 6 Figuring the Magnification To figure the magnification you must first know the focal length of your telescope. Many times the focal length will be 700mm to 900mm. Here is the formula to figure the magnification. Focal Length in mm Magnification = Eyepiece in mm X Barlow Lens (ie 2X or 3X) Eyepiece Eyepiece 3X Barlow Lens Focusing Tube on the telescope. Assuming the eyepiece is 20mm and the focal length is 900mm, here are the magnifications of each set up. [. . . ] Note: when this is done you will not have to touch either of these knobs again for the rest of the night. 14 Once the Declination Setting is set you will NOT have to touch this again for the rest of the night. 190-200-210-220-230- There will be numbers on the Declination Setting and either an arrow or a pointer. Turn the DIAL `til the pointer or arrow is at 9 then tighten the Declination Lock Knob. (9 stands for 90 degrees. ) 15 190-200-210-220-230- Next, you will need to find the second star I talked about earlier. See the Star Atlas and it will show you some fairly easy stars that should be bright in the sky during different times of the year. [. . . ]