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CARING FOR YOUR TELESCOPE
Your DS-114AT telescope is a precision optical instrument designed to yield a lifetime of
rewarding observations. Given the care and respect due any precision instrument, your tele-
scope will rarely, if ever, require factory servicing. Maintenance guidelines include:
a. Avoid cleaning the telescope’s optics: a little dust on the front surface of the telescope’s
correcting lens causes virtually no degradation of image quality and should not be consid-
ered reason to clean the lens.
b. When absolutely necessary, dust on the front lens should be removed with gentle strokes
of a camel hair brush or blown off with an ear syringe (available at any pharmacy). DO
NOT use a commercial photographic lens cleaner.
c. Organic materials (e.g., fingerprints) on the front lens may be removed with a solution of
3 parts distilled water to 1 part isopropyl alcohol. You may also add 1 drop of biodegrad-
able dishwashing soap per pint of solution. Use soft, white facial tissues and make short,
gentle strokes. Change tissues often.
CAUTION: Do not use scented or lotioned tissues or damage could result to the
optics.
d. If used outdoors on a humid night, water condensation on the telescope surfaces will prob-
ably result. While such condensation does not normally cause any damage to the tele-
scope, it is recommended that the entire telescope be wiped down with a dry cloth before
the telescope is packed away. Do not, however, wipe any of the optical surfaces. Rather,
simply allow the telescope to sit for some time in the warm indoor air, so that the wet opti-
cal surfaces can dry unattended.
e. If your telescope is not to be used for an extended period, perhaps for one month or more,
it is advisable to remove the batteries from the battery pack. Batteries left in the battery
pack for prolonged periods may leak, causing damage.
f.
Do not leave the telescope inside a sealed car on a warm summer day; excessive ambi-
ent temperatures can damage the telescope’s internal lubrication and electronic circuitry.
Collimation
Your DS-114AT may occasionally require re-alignment, particularly if the telescope has
received rough handling in shipment. Good optical alignment is essential for telescope per-
formance, and in any case the alignment procedure is not difficult to follow.
The optical systems of the DS-114AT reflecting telescopes includes the following parts: primary
mirror (1, Fig. 26); secondary mirror (2, Fig. 26); secondary mirror-holder (3, Fig. 26); secondary
mirror-vanes (4, Fig. 26) and (1, Fig. 27); primary mirror-tilt screws (5, Fig. 26). The telescope’s
image is brought to a focus at (6, Fig. 26).
1. Confirm alignment - To confirm optical alignment look down the focuser drawtube (1,
Fig. 29) with the eyepiece removed. The edge of the focuser drawtube frames reflections
of the primary mirror (2, Fig. 29), the secondary mirror (3, Fig. 29), the three (“spider”)
vanes (4, Fig. 29) holding the secondary mirror, and the observer’s eye (5, Fig. 29). With
the optics properly aligned, all of these reflections appear concentric (centered), as shown
in Fig. 29. Any deviation from concentricity of any of these telescope parts with the eye
requires adjustments to the secondary mirror-holder (Fig. 27) and/or the primary mirror cell
(Fig. 28), as described below.
2. Secondary mirror-vane adjustments: If the secondary mirror (1, Fig. 30) is left or right of cen-
ter within the drawtube (2, Fig. 30), slightly loosen the 3-vane adjustment/lock knobs (1, Fig. 27)
located on the outside surface of the main tube and slide the entire secondary mirror-holder sys-
tem up or down in the slotted holes of the main tube until the secondary mirror is centered in the
drawtube. If the secondary mirror (1, Fig. 30) is above- or below-center within the drawtube,
thread inward one of the adjustment/lock knobs (1, Fig. 27) while unthreading another of these
knobs. Only make adjustments to two knobs at a time until the secondary mirror appears as in
Fig. 31.
