Home >> Science & Nature >> Astronomy

Step-by-Step for a Polar Meade ETX90

The ETX series of telescopes from Meade is designed to make sky gazing a simple process. But while the telescopes are easy to use, their setup can be tricky. Follow a few simple steps to assemble a Meade ETX90, which uses an equatorial mount and electronic drive system to allow instant access to over 12,000 astronomical objects.

Things You'll Need

Towels
Pliers
Owner's manual

Instructions

- 1
  
  Lay the components on a clean towel.
  
  Lay a clean towel across the work surface where the telescope will be assembled. Remove each telescope component from the box and place it on the towel. The ETX90 is made up of delicate parts that can be easily damaged.
- 2
  Mount the eyepiece. Place the metal shaft of the eyepiece into its mount on the back of the telescope. The mount has an opening the same diameter as the eyepiece and sits perpendicular to the telescope's back. Tighten the mount's set screw clockwise until it stops rotating.
- 3
  
  The viewfinder is a smaller telescope that helps align the larger telescope.
  
  Position the viewfinder. The viewfinder is a smaller telescope that attaches to a pair of mounting rings on the left side of the ETX90. Loosen the set screws on each ring. Slide the viewfinder into the rings. Gently tighten the set screws until the viewfinder is held firmly in place.
- 4
  
  The ETX90 uses eight AA batteries.
  
  Insert the batteries. The ETX90 uses eight AA batteries. Lay the telescope on its side. Remove the battery cover from the bottom of the telescope. Insert the batteries. Match the polarity indicators making sure the positive end of each battery matches the positive polarity marker inside the battery compartment. Replace the cover.
- 5
  
  The controller's plug is similar to a telephone plug.
  
  Plug in the electronic controller. Turn the power switch to the "off" position. Insert the controller's plug into the port labeled "HBX." The ETX90's plug and port are similar to the plug and jack found on a telephone.
- 6
  
  Do not over-tighten the mount's knobs.
  
  Tighten the horizontal and vertical locks. These two locks allow the ETX90 to maintain a position once an astronomical object is located. The vertical locks are located on the top of each of the telescope's pronged mounts. The horizontal mount is located on the top of the mount's base. The locks are controlled by large circular knobs. Turn the knobs clockwise to tighten them.
- 7
  Align the equatorial wedge. On top of the ETX90's tripod is an adjustable wedge. On the side of the wedge is a set screw and degree scale. Loosen the set screw and set the wedge to 38 degrees. Turn the screw clockwise until tight.
- 8
  
  Use pliers to tighten the tripod's mounting screws.
  
  Mount the telescope on the tripod. Insert the mounting screws into the bottom of the tripod's wedge. Place the telescope on the wedge. The telescope has three threaded holes that must be aligned with the mounting screws. After alignment, tighten the screws with a pair of pliers.
- 9
  Turn the telescope on. After a series of system tests, the telescope will be ready to use. For optimal viewing, consult the ETX90 owner's manual to align the telescope with an astronomical object. In the Northern Hemisphere, the North Star is used for alignment.

Astronomy