Meade ETX operating instructions Polar Alignment Procedures, Using a Polar Aligned Telescope

d.Thread the two provided l/4-20 threaded attachment knobs through the mounting slots into the ETX base. Tighten to a firm feel only. Do not overtighten or damage to the threads may occur.

The ETX Astro Telescope can be used for land or celestial observing. To track celestial objects, polar alignment is required, along with the motor drive system of the ETX. (See the Motor Drive section of the ETX instruction manual.)

POLAR ALIGNMENT

Polar alignment is the process of lining up the telescope’s polar axis with the North Celestial Pole (or South Celestial Pole if observing from the southern hemisphere).

With a polar aligned ETX, tracking celestial objects is possible simply by turning on the drive motor in the base of the telescope. The motor counteracts Earth’s rotation, keeping objects in the field of view. Also, with a polar aligned telescope, the ETX’s Dee and R.A. setting circles may be used to locate faint objects directly from their catalogued coordinates.

Fig. 3. (left) The ETX Astro Telescope on Field Tripod. ownted for land wewIng. (right) The polar-allgned ETX, ready for astronomlcal wewng.

1 . Polar Alignment Procedures

Make sure the ETX is firmly attached to the tripod, as described above In this tnstruction sheet, with latitude lock knob (10) and the latitude lock lever (11) Fig 1. firmly locked

Step (a) below IS equrvalent to pointing the telescope’s polar axls due north (or due south for observers in the southern hemisphere). Step (b) IS equrvalent to makrng the telescope’s latitude angle equal to the latitude angle of your obset-vmg location.

a.On top of one of the tripod legs, locate the letter “N”(8) Fig. 1. This represents the north leg of the tnpod. Prck up the entire telescope-and-tripod and onent the tripod u tf@ lea marked “N”points due north. For observers In the southern hemisphere (e.g., Australra), the lea marked “N” should pornt due south.

Note: By following the procedures listed above, the ETX telescope is polar aligned for most celestial observing

applications. See Figure 3. Approximate polar alignment is * sufficient in the great majority of these applications. Do not

allow a time-consuming effort at precise polar alignment to interfere wifh your basic enjoyment of the telescope, as such precise alignment is, in general, not reqtiired.

Using the North Star, Polaris, to find North aids in the polar alignment procedure. Polaris can be found in relation to the Big Dipper by projecting a line from the so-called “pointer stars” of the Big Dipper. For southern hemisphere alignment, locate south by using the faint star Sigma Octans (the South Star)

0 *...__b

*...“’

Cassiopeia

Fig. 4: Locating Polaris.

2.Using a Polar Aligned Telescope

Once the telescope is polar aligned, the ETX motor drive will keep a celestial object in the field of view of the telescope.

a.To center a celestial object within a polar aligned telescope, unlock the Dee and R.A. lock levers of the telescope (see the Locating Astronomical Objects section of the ETX instruction manual). Do not move the tripod or adjust the latitude angle when centering an object in the telescope, as this will destroy the polar alignment.

b.Once a celestial object has been centered in the telescope, lock the Dee and R.A. lock levers.

C . Locate the On/Off switch on the bottom of the ETX drive

base and turn on the motor drive. The motor drive will keep the celestial object within the telescope’s field of view.

Note: Depending on the accuracy of the alignment procedure, it may be necessary to use the R.A. and Dee Slow Motion Controls to make minor adjustments to keep the celestial object in the field of view.

d.The motor drive disengages when the R.A. and Dee lock levers are unlocked and re-engages when the lock levers are locked, making it possible for the motor drive to remain on during the entire observing session.

e.At the end of an observing session, remember to turn off the motor drive.

b.Determine the latitude of your observing locatron by

	checking a road map, atlas, or refer to pages 12-13 of the	3. Terrestrial Use of the Field Tripod
	ETX manual. To set the latitude of the tripod to your	In land viewing applications, the three legs of the Field Tripod
	obseN!ng location, loosen the latitude lock knob (lo),
		may be posrtioned In an arbitrary orientation. The telescope
	Fig. 1. Turn the fine latitude adjustment knob (4) Fig. 1,
		mounting, however, should be placed in a horizontal positron:
.	clockwise or counterclockwise until the latitude pointer
		(Fig. 3) by turning the fine latitude adjustment knob (4) Frg. 1,
	Indicates the correct latitude on the latitude scale (3) Fig. 1.
		to read 90”, unlocking and re-lockrng the latitude lock knob‘(lO),
	It may be necessary to loosen the lock nut on the fine
		Fig. 1, to accomplish this adjustment. The ETX’s motor drive
	latitude adjustment knob (4) Fig. 1, to allow enough
		should be turned off In terrestnal		applications. Use	the
	movement of the mount to achieve the latitude of your
		telescope’s R.A. and Dee slow-motion controls for fine motion in
	location. Once the desrred latitude has been set, tighten
		horizontal	and vertical.
	the lock nut until it is flush agamst the mount. Trghten the
	latitude lock knob (lo), Fig. 1, as well.	.
	Note: The fine azimuth adjustment knobs (9), Fig. 7, which	If you have any questions regarding the use of the ETX Field
	move the telescope horizontally without moving the tripod itself,	Tripod,	please call Meade	Customer Service	at
	may be used to aId m the alignment procedure.	(949) 451-1450.