Key Features Explained - Meade EXT90 Instruction Manual

1
Eyepiece: Place the supplied 26mm eyepiece into
the 90° Eyepiece Holder (Pg 13, Fig. 3, 4) and tighten
in place with thumbscrew (Pg 13, Fig. 3, 3).
2
Red Dot Viewfinder: Provides an easier way to
initial sight objects than in the main telescope eyepiece
which has a narrower field of view. Turn the knob
located underneath the viewfinder lens to turn on/off
the red dot and change the intensity of the dot. (Note:
Be sure to turn off the red dot when not in use.)
3
Eyepiece Holder Thumbscrew: Tightens the
eyepiece in place. Tighten to a firm feel only.
4
90° Eyepiece Holder: Holds the eyepiece upright
for easy viewing.
5
Optical Tube: The main optical component that
gathers the light from distant objects and brings this
light to a focus for examination with the eyepiece.
6
Vertical Lock: Controls the manual vertical
movement of the telescope. Turning the vertical lock
counterclockwise unlocks the telescope enabling it
to be freely rotated by hand about the vertical axis.
Turning the vertical lock clockwise (to a firm feel only)
prevents the telescope from being moved manually,
but engages the vertical motor drive clutch for AutoStar
operation. When polar aligned, the vertical lock serves
as the Declination or Dec. lock.
Note: The vertical lock knob is a knurled knob located
on the fork arm to the right of the focus knob (Pg 13,
Fig. 3, 8). Mounted beneath the knob is a circular scale
without numbers. Do not confuse this scale with the
Dec. setting circle (Pg 14, Fig. 4, 22) on the opposite
fork arm which has a numbered scale used to locate
astronomical objects manually.
7
Fork Arms: Hold the optical tube in place.
8
Focus Knob: Moves the telescope's primary mirror
in a finely-controlled motion to achieve precise image
focus. The ETX telescopes can be focused on objects
from a distance of about 11.5 ft to infinity. Rotate the
focus knob clockwise to focus on distant object. Meade
makes a complete line of accessories to enable you to
get the most fun and performance from your ETX90
telescope. No matter what you want to accomplish, we
have the equipment to help you get there
9
Horizontal Lock: Controls the manual horizontal
rotation of the telescope. Loosen the horizontal lock
counterclockwise to unlock the telescope, enabling it
to be freely rotated by hand about the horizontal axis.
Tightening the horizontal lock clockwise prevents the
telescope from being rotated manually, but engages
the horizontal motor drive clutch for AutoStar operation.
When polar aligned, the horizontal lock serves as the
Right Ascension or R.A. lock.

Computer Control Panel (see Pg 14, Fig. 7)

ON/OFF Switch: Turns the Computer Control Panel
and AutoStar handbox ON or OFF.
Note: Always remove the batteries if they are not to
be used for a long period of time.

Auxiliary (AUX) Port: Provides connection for
current and future Meade accessories. See OPTIONAL
ACCESSORIES, page 17.

Handbox (HBX) Port: Plug the AutoStar handbox
into this port.

Battery Connector (not shown, accessible thru
battery compartment door on top of base housing):
is designed to accept an external power supply such
as the optional #546 AC Adapter (see OPTIONAL
ACCESSORIES, page 19).

LED: The red power indicator light illuminates when
power is supplied to the telescope's motor drive.

Base Housing: Supports the telescope for
placement on a flat, level surface, such as a tabletop
or tripod.
1&
Battery Compartment (not shown, accessible thru
battery compartment door on top of base housing):
Install six user-supplied AA batteries , oriented as
shown on the diagram on the battery slots of the
battery holder in this compartment. See page 6 for
more information. Replace the cover.
CAUTION: Use care to install batteries as indicated
by the battery compartment. Follow battery
manufacturer's precautions. Do not install batteries
backwards or mix new and used batteries. Do not
mix battery types. If these precautions are not
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