Instructions / Assembly

21
ETX 90 KEY FEATURES
13. Vertical setting circle: (on left fork arm): See
page 58 for detailed information.
14. 90 degree ip mirror: ETX telescopes include
an internal mirror. With the ip-mirror control in
the “up” position light is diverted to the eyepiece.
With the ip-mirror control in the “down” position
light proceeds straight out the photo port for
photography.
Note: The ip-mirror control is in the “up” position
when the control is vertical (perpendicular to
the telescope tube). To place the ip-mirror in
the “down” position, turn the control until it is
horizontal.
15. Front lens: The high quality 90mm optics start
with a front lens made of optical glass. The primary
and secondary mirrors are carefully aligned inside
the optical tube to provide the best image possible.
16. OTA mounting thumbscrews: Attaches the ETX
optical tube to the mount using two ¼-20 mounting
screws. Take off the optical tube to reduce the
telescope weight or size. Install another optical
tube to make the ETX observer even more
versatile.
17. Bubble level/compass: Used to aide in setting
the telescope in the Home Position. See page 19.
When placed in the 90° eyepiece holder the bubble
level compass can be used to level the telescope
and determine the direction of magnetic North.
18. Horizontal lock knob: 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
AudioStar operation. When polar aligned, the
horizontal lock serves as the Right Ascension
or R.A. lock.
19. Battery compartment: Accessible thru the 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 7 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 followed, batteries
may explode, catch re, or leak. Improperly
installed batteries void your Meade warranty.
Always remove the batteries if they are not to
be used for a long period of time.
20. Horizontal setting circle: See page 58 for
detailed information.