Tools
The Comet Hunter uses standard metric hex wrenches and a flat-head screwdriver to make most of the adjustments. Upon
registering the product, our Customer Service department will provide a special primary mirror collimation adjustment tool that
allows more precise adjustments, and the ability to hold the final adjustment securely while the mirror cell is locked.
Using and Adjusting the Focuser
The David H. Levy Comet Hunter 152mm f/4.8 Maksutov-Newtonian comes standard with a 10:1 Two-Speed Crayford-Style
focuser, which allows for precise focusing.
You can change the tension of the eyepiece holder. Just screw the tension knob (
1, Fig. 7
) a little bit till you have the preferred
focus knob tension.
If you want to lock the eyepiece holder, please tighten the lock knob (
2, Fig.7
).
If you wish to further change the tension, you can adjust the two sets of three screws on the
focuser’s top side. The center silver
hex screws hold a semi circular plate with four bearings that press on the draw tube. If you loosen the center screws (and the
tension control screw), you can adjust the four black hex screws to provide the desired pressure. You need do this is very small
increments
– too tight and the draw tube will focus roughly and too loose the focuser will not hold position well. After adjustment
the center screws should be retightened and tightening the tension control screw will be more aggressive.
Using 1.25” and 2” O.D. Eyepieces:
The Comet Hunter comes standard with a 2” diameter focuser. To use 2” O.D. eyepieces, remove the dust cover, release the
eyepiece holder set screw, and slide the eyepiece barrel into the focuser. Tighten the eyepiece holder set screw to secure the
eyepiece.
To use 1.25” O.D. eyepieces, slide the 1.25” eyepiece adapter (
9, Fig. 1
)
in the 2” eyepiece holder in the same manner that you
would when inserting a 2” O.D. eyepiece, then secure it in place by tightening the 2” eyepiece holder set screw. Then release the
1.25” eyepiece holder set screw and slide in the eyepiece barrel into the adapter. Tighten the 1.25” adapter eyepiece holder set
screw to secure the eyepiece.
Using the Extension Tube:
Depending on the focal length of the eyepiece or type of camera that you are using on the Comet Hunter, you may need extra
extension of the focuser drawtube to reach focus. The 40mm 2” O.D. focuser extension tube
(10, Fig. 1)
is supplied as standard
equipment for this purpose. To attach it, grasp the eyepiece holder section of the focuser and turn it counterclockwise to free the
end of the focuser drawtube. Then thread on the focuser extension tube clockwise and tighten it to a firm feel, then thread on the
end of the eyepiece holder section to a firm feel.
The Dew Shield
The Comet Hunter comes standard with a carbon fiber dew shield
(12, Fig. 1)
that attaches to the front cell of the telescope tube
with a friction fit. We advise using the dew shield at all times possible to eliminate stray light and slow the progress of dew forming
on the corrector plate.
Note that you can leave the dew shield on when storing in the case, or if the telescope is permanently set up in an observato ry,
because the front dust cover
(11, Fig. 1)
fits over the end of the dew shield when the telescope is not in use.
Fig. 7, 10:1 Two-Speed Focuser
Adjustments
1
2
