Meade ETX-90EC, ETX-105EC, ETX-125EC Installation Instructions

Instruction Manual

ETX-90AT Astro Telescope

ETX-105AT Astro Telescope

ETX-125AT Astro Telescope

WARNING!

Never use a Meade® ETX® Astro Telescope to look at the Sun! Looking at or near the Sun will cause instant and irreversible damage to your eye. Eye damage is often painless, so there is no warning to the observer that damage has occurred until it is too late. Do not point the telescope or its viewfinder at or near the Sun. Do not look through the telescope or its viewfinder as it is moving. Children should always have adult supervision while observing.

Caution: Use care to install batteries in the orientation indicated by illustration in the battery slots of 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 fire or leak. Improperly installed batteries void your Meade warranty.

If you are anxious to use your telescope for the first time, read the QUICK-START GUIDE on pages 4 and 5.

® The name "Meade," “ETX,” “Autostar” and the Meade logo are trademarks registered with the U.S. Patent Office and in principal countries throughout the world.

Patents:

US 6,304,376

US 6,392,799

US 6,563,636

D 422,610

Patent Pending

© 2004 Meade Instruments Corporation.

CONTENTS
Quick-Start Guide ..........................................................	4
Telescope Features ......................................................	6
Autostar Features ..........................................................	9
Getting Started ..............................................................	12
Parts Listing ..............................................................	12
How to Assemble Your Telescope & Tripod ..............	12
Attaching and Using the Viewfinder ..........................	13
Focusing and Aligning the Viewfinder ......................	14
Choosing an Eyepiece ..............................................	15
Observing ......................................................................	16
Observing by Moving the Telescope Manually ........	16
Terrestrial Observing ................................................	16
Observing Using Autostar's Arrow Keys ..................	16
Slew Speeds ............................................................	17
Astronomical Observing, Observe the Moon ............	17
To Track an Object Automatically..............................	17
Moving Through Autostar’s Menus......................	17
Initializing Autostar ..............................................	18
Easy (Two-Star) Align..........................................	18
Observe a Star Using Automatic Tracking ..........	20
Go To Saturn ............................................................	20
Using the Guided Tour ..............................................	21
Basic Autostar Operation................................................	22
Autostar Navigation Exercise ....................................	22
Entering Data, Navigating Autostar ..........................	23
Autostar Menus ............................................................	24
Menu Tree ................................................................	24
Objects Menu............................................................	25
Event Menu, Glossary Menu ....................................	26
Utilities Menu ............................................................	27
Setup Menu ..............................................................	28
Advanced Autostar Features ..........................................	31
Adding Observing Sites ............................................	31
Finding Objects Not in the Database........................	32
Observing Satellites ..................................................	32
Create Your Own Guided Tour..................................	33
Landmarks ................................................................	36
Identify ......................................................................	37
Advanced Alt/Az Alignment Methods ........................	38
Browse ......................................................................	39
Photography ..................................................................	40
Photography with Autostar Suite ..............................	42
Optional Accessories ......................................................	43
Maintenance ..................................................................	45
Troubleshooting ......................................................	46
Specifications ................................................................	48
Appendix A: Equatorial (Polar) Alignment ......................	51
Equatorial Alignment, Celestial Coordinates ............	51
Polar Mounting with #884 Deluxe Field Tripod ........	51
Equatorial Mounting Procedure ................................	52
To Track a Star When Polar Mounted ......................	52
Autostar Polar Alignment Modes ..............................	53
Locating the Celestial Pole ......................................	53
Setting Circles ..........................................................	54
Appendix B: Latitude Chart ............................................	55
Appendix C: Training the Drive ......................................	56
Appendix D: Basic Astronomy ........................................	57

QUICK-START GUIDE

This Quick Start Guide demonstrates how to install the batteries and eyepiece, and how to observe using the Autostar Arrow keys. If you wish to try out Autostar’s “Go To” capabilities, check out the list of page references at the bottom of the following page.

B

B

A

Remove the ETX® telescope from its packaging and place it on a sturdy surface. Place the ETX on its side and remove the battery compartment cover (A) from the underside of the drive base. Insert eight (user-supplied) AA-size batteries into the battery compartment (B) oriented as shown in the battery compartment. Replace the cover and return the telescope to an upright position (if you wish to attach the telescope to the deluxe field tripod, see page 12).

C C

D

E

Place the 26mm eyepiece (C) into the eyepiece holder on the telescope and tighten the attachment thumbscrew (D) to a "firm feel" only. See page 7, for more information. Remove the dust cover (E) from the end of the telescope tube.

D

G F

Make sure that the computer control panel power switch (F) is in the OFF position. Remove the Autostar® handbox and the coiled cord from the packing materials. Plug one end of the cord into the HBX port (G).

H

...and the other end of the coiled cord into the coiled cord port at the bottom of Autostar handbox (H), as shown above.

IJ

Tighten (to a "firm feel" only, do not overtighten) the vertical lock (I) and the horizontal lock (J). See page 7 and 8 for more information.

F

Flip the Power Switch (F) on the computer control panel to the ON position. A copyright message lights on Autostar’s LCD display, followed by a warning not to look at the Sun. Press the Autostar key prompted by the message when you are done reading.

A “Getting Started” message displays. Press ENTER to skip this message.

See pages 9 to 11 for more information about Autostar’s keys.

4

Enter

Key

							Scroll
	Scroll Up
							Down
	Key
							Key

Keep pressing the ENTER key until "Country/State" appears on the display. (Ignore the prompts requesting "Date" and "Time" for now – these functions will be explained later).

When “Country/States” displays, press either one of the SCROLL KEYS to cycle through the choices on the list. When your state or country appears on the list, press ENTER.

“Cities” displays. Using the SCROLL KEYS, cycle through the list of cities and press ENTER when the city closest to you displays.

Finally “Telescope Models” displays. Using the SCROLL KEYS, cycle through the list of telescope models and press ENTER when your model displays.

The display now displays "Setup: Align." See page 19 for more information.

If Autostar does not requests the Country/State, City and Telescope Model information, use the "Telescope Model" and "Site" options in the Setup menu to change this information. See pages 28, 29 and 31 for more information.

L

K

Make sure that the flip mirror control (K) is in the “Up” position, as shown the diagram above.

L

Arrow	Arrow
Keys	Keys

Number

Keys

You can now use the ARROW KEYS to slew (move) the telescope up, down, right or left. Practice using the ARROW KEYS to center objects in the eyepiece.

To change the speed at which the telescope moves (known as the “slew” speed) press a NUMBER KEY from 1 through 9. 1 is the slowest speed and 9 is the fastest.

Sight along the side of the telescope’s main tube to locate an object. If you wish to learn how to attach and align the telescope’s viewfinder, see pages 13 to 14.

Use the telescope’s focus knob (L) to bring the object into focus.

If you wish to observe using Autostar’s databases, see:

Page 19 to learn how to perform an Easy Alignment Page 20 to “Go To” Saturn”

Page 21 to learn about Guided Tours

Pages 22 to 39 to learn more about Autostar’s menus

5

TELESCOPE FEATURES

18

1

2

17

16

(on left fork arm)

15

14

13

11

		Fig. 1: The ETX-90AT Telescope.
	1		Eyepiece	11	Base Housing
	2		Viewfinder	12	Battery Compartment
	3		Holder Thumbscrew		(bottom of base)
	4		90° Eyepiece Holder	13	Right Ascension (R.A.)/
	5		Optical Tube		Horizontal Setting Circle
				14 Flip-Mirror Control Knobs
	6		Vertical Lock
				15	Photo Port
	7		Fork Arms
				16	Declination (Dec.)/Vertical
	8		Focus Knob
					Setting Circle
	9		Horizontal Lock
				17	Viewfinder Alignment Screws
	10		Computer Control Panel
				18	Viewfinder Alignment Bracket
			A. ON/OFF Switch
				19	Dust Cap
			B. Auxiliary Ports (2)
			C. Handbox Port
			D. 12v
	6		E. LED

Features of the ETX-90AT, ETX-105AT, 3 4 5 and ETX-125AT are identical, with the

exception of the size of optical tube and the type of viewfinder.

19

6

7

8

9

10

12

E

B C D A B

Fig. 2 (Inset): Computer Control Panel. (A) On/Off switch; (B) Auxiliary ports; (C) Handbox port; (D) 12v connector; (E) Power indicator light.

Caution:

Using products other than standard Meade accessories may cause damage to the telescope’s internal electronics and may void the Meade warranty.

B Want to learn more about the eyepieces available for your ETX telescope?

See OPTIONAL ACCESSORIES, pages 43 to 44.

c Want to learn how to attach the viewfinder to your ETX telescope?

See VIEWFINDER, pages 13 and 14.

G Want to learn more about the Right

Ascension and Declination setting

circles? See page 54.

Caution:

When loosening the Dec. lock, be sure to support the optical tube (5 Fig. 1). The weight of the tube could cause the tube to swing through the fork arms suddenly.

MEADE ETX: YOUR PERSONAL WINDOW TO THE UNIVERSE

The Meade ETX-90AT, ETX-105AT and the ETX-125AT are extremely versatile, highresolution telescopes. With pushbutton controls, automatic tracking of celestial objects and diffraction-limited imaging, an ETX telescope may be all the telescope ever required by many terrestrial and astronomical observers.

Your ETX telescope reveals nature in an ever-expanding level of detail. Observe the feather structure of an eagle from 50 yards or study the rings of the planet Saturn from a distance of 800 million miles. Focus beyond the Solar System and observe majestic nebulae, ancient star clusters, remote galaxies and even stars recently discovered to have planets orbiting about them. Meade ETX telescopes are instruments fully capable of growing with your interest and are ideal for both the casual observer and serious astronomer alike.

Telescope Controls

Become acquainted with all of these controls before attempting observations through the telescope.

BEyepiece: Place the supplied 26mm eyepiece into the 90° Eyepiece Holder (4, Fig. 1) and tighten in place with thumbscrew (3, Fig.1).

CViewfinder

ETX-90AT: 8 x 21mm Viewfinder: Slide the eyepiece end of the viewfinder through the front of the viewfinder bracket (Fig. 18).

ETX-105AT, ETX-125AT: 8 x 25mm Right-Angle Viewfinder: Slide the front cell end of the viewfinder through the rear of the viewfinder bracket (Fig. 19).

DEyepiece Holder Thumbscrew: Tightens the eyepiece in place. Tighten to a firm feel only.

e 90° Eyepiece Holder: Holds the eyepiece upright for easy viewing.

FOptical Tube: The main optical component that gathers the light from distant objects and brings this light to a focus for examination with the eyepiece.

GVertical 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 (8, Fig. 1). Mounted beneath the knob is a circular scale without numbers. Do not confuse this scale with the Dec. setting circle (16, Fig. 1) on the opposite fork arm which has a numbered scale used to locate astronomical objects.

H Fork Arms: Hold the optical tube in place.

Note: The telescope base and fork mount are designed with internal “rotational limit stops.” The horizontal limit stop prevents the telescope from rotating more than 630° to avoid damage to the internal wiring. The vertical limit stop prevents the viewfinder from striking the fork mount when the telescope is pointed upward just past 90° and prevents the optical tube from striking the base if pointed downward more than 30°. Do not force the telescope to move beyond these stops or damage to the telescope will result.

iFocus 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 (ETX-90AT) or 15 ft (ETX-105AT or ETX-125AT) to infinity. Rotate the focus knob clockwise to focus on distant objects and counterclockwise to focus on nearby objects.

7

Definitions

Throughout this manual, you will notice the terms "Alt/Az," "Right Ascension," and "Declination." Alt/Az or more properly, altazimuth, is frequently used to refer to altitude or Declination (the up-and-down vertical movement of the telescope) and azimuth or Right Ascension (the side-to-side horizontal movement of the telescope). Right Ascension is abbreviated as "R.A." and Declination as "Dec."

Fig. 3a: Flip mirror control in the “up” position.

Fig. 3b: Flip mirror control in the “down” position.

1* Want to learn more about attaching and aligning the viewfinder?

See pages 13 and 14.

1( Note: The dust cap should be replaced after each observing session and the power turned off to the telescope. Verify that any dew that might have collected during the observing session has evaporated prior to replacing the dust cap. Do not overtighten.

jHorizontal 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.

1)Computer Control Panel (see Fig. 2)

A.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.

B.Auxiliary (AUX) Ports (2): Provide connection for current and future Meade accessories. See OPTIONAL ACCESSORIES, page 43.

C.Handbox (HBX) Port: Plug the Autostar handbox into this port.

D.12v: The 12v connector is designed to accept an external power supply such as the optional #541 AC Adapter or the #607 Power Cord (see OPTIONAL ACCESSORIES, page 43). When one of the external power supply options is used, the internal batteries are disconnected from the power circuit.

E.LED: The red power indicator light illuminates when power is supplied to the connected handbox and to the telescope’s motor drive.

1! Base Housing: Supports the telescope for placement on a flat, level surface, such as a tabletop or tripod.

1@ Battery Compartment (not shown, underneath base): Install eight user-supplied AA batteries in this compartment. See page 12 for more information.

1# Right Ascension (R.A.) Setting Circle: See page 54 for detailed information.

1$ Flip-Mirror and Flip-Mirror Control Knobs: ETX telescopes include an internal mirror. With the flip-mirror control in the “up” position, as shown in Fig. 3a, light is diverted to the eyepiece. With the flip-mirror control in the “down” position, as shown in Fig. 3b, light proceeds straight out the photo port for photography. See

PHOTOGRAPHY, page 40.

Note: The flip-mirror control is in the “up” position when the control is vertical (perpendicular to the telescope tube). To place the flip-mirror in the “down” position, turn the control until it is horizontal.

1% Photo Port: Attach any 35mm camera with a removable lens to this port using an optional #64ST T-Adapter or attach the #932 Erecting Prism for correctly oriented images through the eyepiece. See OPTIONAL ACCESSORIES, page 43.

1^ Declination (Dec.) Setting Circle (on left fork arm): See page 54 for detailed information.

1& Viewfinder Alignment Screws: Adjust these screws to align the viewfinder. See pages 13 and 14 for more information.

1* Viewfinder Alignment Bracket: Attach the viewfinder to this bracket. See pages 13 and 14 for more information.

1( Dust Cap: Unthread the dust cap counterclockwise from the front lens of the telescope.

8

Want to learn more about downloading the latest updates of Autostar software from the Meade website? See pages 29 and 43.

AUTOSTAR FEATURES

	L
1
2	4
3
5		1 LCD Display
		2 ENTER Key
6		3 MODE Key
		4 GO TO Key
		5 Arrow Keys
	K	6 Number Keys
7		7	Scroll Keys
		8 Speed/? Key
	8	9	Coil Cord
		10 RS232 Port
9	J	11	Light key
		12	Utility Light

Fig. 4: The Autostar Handbox.

Tour the Cosmos with Just the Push of a Button

Control of ETX Telescopes is through the operation of the standard-equipment #497 Autostar. Nearly all functions of the telescope are accomplished with just a few pushes of Autostar’s buttons. Some of the major features of Autostar are:

•Automatically move the telescope to any of the 30,000 objects stored in the database or manually enter the astronomical coordinates of any celestial object.

•Take a guided tour of the best celestial objects to view on any given night of the year.

•Download the latest satellite data, guided tours and software revisions directly from the Meade website (www.meade.com) and share software with other Autostar enthusiasts. (Requires optional #505 AstroFinder™ Cable Connector Kit. See OPTIONAL ACCESSORIES, page 43.)

•Access a glossary of astronomical terms.

•Calculate which eyepiece to use for optimum viewing of a celestial object.

Autostar provides control of virtually every telescope function. The Autostar handbox has soft-touch keys designed to have a positive feel. The LCD (Liquid Crystal Display) is backlit with red LEDs (Light Emitting Diodes) for easy viewing in the dark. The backlit display, key arrangement and sequential menu structure make Autostar extremely user friendly.

9

e

g

Want to learn more about using the GO TO function? See page 20.

Want to learn how to perform a spiral search? See page 20.

Want to learn more about changing slew speeds? See page 17.

B 2-Line LCD Display: This screen displays Autostar's menus and information about the telescope.

•Top line: Lists the primary menu.

•Bottom line: Displays other menus that may be chosen, menu options, telescope status or information about a function that is being performed.

c ENTER Key: Press to go to the next menu level or to choose an option in a menu. The ENTER key is similar to the RETURN or ENTER key on a computer. See MOVING THROUGH AUTOSTAR’S MENUS, page 17 and AUTOSTAR MENUS, page 24.

d MODE Key: Press to return to the previous menu or data level. The top menu level is “Select Item." The MODE key is similar to the ESCAPE key on a computer.

Note: Pressing MODE repeatedly while in the “Select Item” level moves Autostar to the topmost screen: “Select Item: Object.”

Note: If MODE is pressed and held for two seconds or more, information about the telescope's status displays. When the status displays, press one of the Scroll keys (7, Fig. 2) to display the following information:

•Right Ascension and Declination (astronomical) coordinates

•Altitude (vertical) and Azimuth (horizontal) coordinates

•Local Time and Local Sidereal Time (LST)

•Timer and Alarm Status

•Date

•Site coordinates

•Battery status

Press MODE again to return to the previous menu.

e GO TO Key: After the telescope is aligned, press to slew (move) the telescope to the coordinates of the currently selected object. While the telescope is slewing, the operation may be aborted at any time by pressing any key except GO TO. Pressing GO TO again resumes the slew to the object. Also, press during the alignment or GO TO procedures to activate a "spiral search."

f Arrow Keys: The Arrow keys have several functions. Press an Arrow key to slew the telescope in a specific direction (up, down, left and right), at any one of nine different speeds. See SLEW SPEEDS, page 17. Use the Up and Down Arrow keys to move the telescope vertically up and down. The Left Arrow key rotates the telescope horizontally counterclockwise, while the Right Arrow key rotates it clockwise.

Also, use the Arrow keys to scroll through numbers 0 through 9 and the alphabet. The Down Arrow key begins with the letter "A;" the Up Arrow key begins with digit "9."

Additionally, use the Arrow keys to to move the cursor across the display: Use the Right or Left Arrow key to move the cursor from one number to the next in the display.

g Number Keys: Press to input digits 0 to 9. To change the speed at which the telescope moves (known as the “slew” speed) press a NUMBER KEY from 1 through 9. 1 is the slowest speed and 9 is the fastest.

h Scroll Keys: Press to access options within a selected menu. The menu is displayed on the first line of the screen. Options in the menu are displayed, one at a time, on the second line. Press the Scroll keys to move through the options. Press and hold a Scroll key to move quickly through the options.

The Scroll keys also control the speed of text scrolling on the Autostar display. When text is scrolling, press and hold the Up Scroll key for a faster display speed and the Down Scroll key for a slower display speed.

10

i ? Key: Press to access the "Help" file. "Help" provides on-screen information on how to accomplish whatever task is currently active.

Press the ? key and then follow the prompts on the display to access details of Autostar functions in the Help feature. The Help system is essentially an on-screen instruction manual.

If you have a question about an Autostar operation, e.g., INITIALIZATION, ALIGNMENT, etc., press the ? key and follow the directions that scroll on the second line. When satisfied with the Help provided, press MODE to return to the original screen and continue with the chosen procedure.

j RS232 Port: Plug in optional cable to download the latest satellite data and software revisions directly from the Meade website (www.meade.com). You can also share software with other Autostar enthusiasts or control your telescope remotely from your PC. (Requires optional #505 AstroFinder™ Software and Cable Connector Kit. See OPTIONAL ACCESSORIES, page 43.)

1) Coil Cord Port/Coil Cord: Plug one end of the supplied Autostar coil cord into this port located at the bottom of the handbox and the other end into the HBX port of the Computer Control Panel.

1!

1@

Light/0 Key: Press to turn on Utility light (12, Fig. 4).

Utility Light: Use this built-in red light to illuminate star charts and accessories without disturbing your eye's adaptation to darkness. Press "0" to turn the light on and off.

ETX TIPS

Join an Astronomy Club, Attend a Star Party

One of the best ways to increase your knowledge of astronomy is to join an astronomy club. Check your local newspaper, school, library or telescope dealer/store to find out if there’s a club in your area.

At club meetings, you will meet other astronomy enthusiasts with whom you will be able to share your discoveries. Clubs are an excellent way to learn more about observing the sky, to find out where the best observing sites are and to compare notes about telescopes, eyepieces, filters, tripods and so forth.

Often, club members are excellent astrophotographers. Not only will you be able to see examples of their art, but you may even be able to pick up some “tricks of the trade” to try out with your ETX telescope. See page 40 for more information about photography with the ETX.

Many groups also hold regularly scheduled Star Parties at which you can check out and observe with many different telescopes and other pieces of astronomical equipment. Magazines such as Sky & Telescope and Astronomy print schedules for many popular Star Parties around the United States and Canada.

11

Cover

Batteries

Fig. 5: Battery installation.

2

1

Fig. 6: Spread tripod legs.

2

Fig. 7: Slide spreader on rod.

3

Fig. 8: Tension knob assembly.

4

Fig. 9: Adjust tripod height.

GETTING STARTED

Parts Listing

Getting the telescope ready for first observations requires only a few minutes. When first opening the packing box, note carefully the following parts:

•The ETX Astro Telescope with fork mount system.

•#497 Autostar handbox with coil cord.

•One or more eyepieces, packed in plastic storage containers.

•Hex-wrench, packed with the instruction manual. See MAINTENANCE, page 45.

•#884 Deluxe Field Tripod; two attachment knobs; spreader tray with separate spring, washers (2) and tension knob; leg extension lock knobs.

How to Assemble Your Telescope and Tripod

Assembly of the ETX telescope requires eight AA-size (user-supplied) batteries.

1.Remove the ETX telescope from its packaging and place it on a sturdy surface. Place the ETX on its side and remove the battery compartment cover from the underside of the drive base. Insert eight (user-supplied) AA-size batteries into the battery compartment oriented as shown in the battery compartment. Replace the cover and return the telescope to an upright position.

Caution: Use care to install batteries as indicated by the diagrams in 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 fire 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.

Note: Autostar does not require batteries; the telescope’s batteries supply power to Autostar.

2.Assemble the #884 Deluxe Field Tripod:

Step a: Spread the tripod (1, Fig. 6) legs apart to a fully open position. Step b: Slide the spreader tray (2, Fig. 7) onto the central threaded rod.

Step c: Slide a washer, followed by the spring, another washer and the tension knob (3, Fig. 8) onto the threaded rod. Tighten the tension knob to a firm feel.

Step d: Adjust the height of the tripod by loosening the leg lock knobs (4, Fig. 9) and adjusting the height of the inner leg extensions. Then retighten the lock knobs.

3.Mount your telescope in the altazimuth (alt/az) mode. If you wish to mount your telescope in the equatorial mode, see EQUATORIAL ALIGNMENT, page 51.

Note: Throughout this manual, you will notice the term "Alt/Az," or more properly, altazimuth. This term is frequently used to refer to altitude or the up-and-down vertical movement of the telescope). Azimuth refers to the side-to-side horizontal movement of the telescope.

Step e: Loosen the latitude control latch (6, Fig. 10) and lift up the tilt-plate (5, Fig. 10) so that you can easily access the underside of the plate. Relock the latitude control latch, so the assembly doesn't slip while you are attaching the telescope.

Step f: Line up the mounting hole (7, Fig. 11) on the base of the telescope marked "High Latitude Leg" with the attachment knob (8, Fig. 11) that is closest to the latitude control bar (9, Fig. 11). Line up the other mounting hole with the attachment knob at the bottom of the tilt-plate. Thread both attachment knobs into the base of the telescope. Tighten to a firm feel only. (See Fig. 12.)

Step g: Unlock the latitude control latch (10, Fig. 13) and lower the tilt-plate until it is level (push the tilt-plate down until it stops; this is the level position). Lock the latitude control latch.

12

			L
			M
5	6		N
						O
			Fig. 15: Insert eyepiece.						Fig. 16: Tighten vertical		Fig. 17: Tighten horizontal
Fig. 10: Loosen control latch .
									lock.		lock.
	7

4. Place the 26mm eyepiece (12, Fig. 15) into the eyepiece holder on the

8telescope and tighten the attachment thumbscrew (13, Fig. 15) to a "firm feel" only. Make sure that the flip-mirror control (14, Fig. 15) is in the “up” position, as shown in the above photo. See page 8, for more information. Remove the dust cover (15, Fig. 15) from the end of the telescope tube.

5.Make sure that the computer control panel power switch (A, Fig. 2) is in the OFF position. Remove the Autostar handbox and the coiled cord from the packing

	9		materials. Plug one end of the cord into the HBX port (C, Fig. 2)and the other end
			of the coiled cord into the coiled cord port at the bottom of Autostar handbox, as
	Fig. 11: High latitude leg		shown above.
	mounting hole and	6.	Tighten (to a "firm feel" only, do not overtighten) the vertical lock (Fig. 6) and the hor-
	corresponding attachment
			izontal lock (Fig. 9).
	knob.
		Attaching the Viewfinder
			ETX-90AT: 8 x 21mm Viewfinder: Slide the eyepiece end of the viewfinder
			through the front of the viewfinder bracket (16, Fig. 18).
			ETX-105AT or ETX-125AT: 8 x 25mm Right-Angle Viewfinder: Slide the front
			cell end of the right-angle viewfinder through the rear of the viewfinder bracket
			(17, Fig. 19).

8Unthread the six alignment screws slightly to fit the viewfinder through the bracket. With the viewfinder in place, tighten the six alignment screws to a firm feel

only against the viewfinder tube.

Using The Viewfinder

As with most astronomical telescopes, the ETX model telescopes present a fairly narrow field of view to the observer. As a result it is sometimes difficult to locate and center objects in the telescope’s field of view. The viewfinder, by contrast, is a low-

Fig. 12: Attach telescope to power, wide-field sighting scope with crosshairs that let you easily center objects in tripod.

the eyepiece of the main telescope’s field of view. The telescope viewfinder is a great help in locating faint astronomical objects before you begin observing through the telescope eyepiece.

ETX-90AT 8 x 21mm Erect-Image Viewfinder:

Standard equipment with the ETX-90AT, the 8 x 21mm Erect-Image Viewfinder has

J8-power magnification and an aperture of 21mm. This viewfinder presents a

correctly oriented image both up-and-down and left-to-right.

	ETX-105AT or ETX-125AT 8 x 25mm Right-Angle Viewfinder:
Fig. 13: Level tilt-plate.	Standard equipment with the ETX-105AT and ETX-125AT, the 8 x 25mm Right-Angle
	Viewfinder has 8-power magnification and an aperture of 25mm. This viewfinder
	presents a correctly oriented image up-and-down, but is reversed left-for-right.

L	P	Q
Fig. 14: Handbox HBX port.
	Fig. 18: ETX-90 Viewfinder Installation. Fig. 19: ETX-105/-125 Viewfinder

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(before

alignment)

1 2 4

5

3

Fig. 20a: ETX-90 Viewfinder:

(1)Front lens cell;

(2)Knurled lock-ring;

(3)Viewfinder eyepiece;

(4)Alignment screws;

(5)Viewfinder bracket;

7

6

Fig. 20b: ETX-105/-125

Viewfinder:

(6)Focus ring;

(7)Viewfinder eyepiece

Focusing the Viewfinder

The ETX model viewfinders are pre-focused at the factory. Individual eye variations may require that the viewfinder be re-focused. To check the focus, point the viewfinder at a distant terrestrial (land) object such as a telephone pole or light pole and look through the viewfinder. If the viewfinder image is not in sharp focus, follow the procedure below that applies to your telescope model.

ETX-90AT

1.Remove the viewfinder by slightly unthreading the six alignment screws (4, Fig. 20a) and slipping it out of the bracket.

2.Loosen the knurled lock-ring (2, Fig. 20a) located near the viewfinder’s front lens cell (1, Fig. 20). Unthread this ring (counterclockwise, as seen from the eyepieceend of the viewfinder) by several turns.

3.Look through the viewfinder and focus on a distant object. Slowly rotate the front lens cell in one direction or the other, until the object appears sharp. One or two rotations of the lens may have a significant effect on image focus.

4.Lock the focus in place by threading the knurled lock-ring clockwise up against the viewfinder’s lens cell.

5.Replace the viewfinder into the viewfinder bracket. Gently tighten the six alignment screws. Proceed with Aligning the Viewfinder.

ETX-105AT or ETX-125AT

Turn the focus ring (6, Fig. 20b) at the base of the viewfinder eyepiece (7, Fig. 20b) in either direction until a sharp focus is reached.

Aligning the Viewfinder

In order for the viewfinder to be useful, it must first be aligned with the main telescope, so that both the viewfinder and the main telescope are pointing at precisely the same location. To align the viewfinder:

1. Turn the three rear alignment screws of the viewfinder bracket (4, Fig. 20a) so that the viewfinder tube is roughly centered within the viewfinder bracket.

Tip: Do not overtighten the alignment screws. When tightening one screw it may be necessary to loosen one or both of the two other alignment screws.

2.Point the main telescope at some tall, well-defined land object, such as the top of a telephone pole. Center the object, as precisely as possible, in the SP 26mm eyepiece's field of view. Tighten the vertical and horizontal locks (6 and 9, Fig. 1) so that the tube cannot move and the object remains centered (1, Fig. 21).

3.While looking through the viewfinder, turn one or more of the three front viewfinder alignment screws (4, Fig. 20a), until the crosshairs of the view-finder point at precisely the

same position as the view through the

eyepiece of the main telescope (2, Fig. 21).

Check that the viewfinder’s								1
crosshairs and			the	main
telescope are now pointing
at precisely the				same
object. The		viewfinder is					View through the		View through the
now aligned to the main							viewfinder		telescope eyepiece
telescope.		Unless		the				(after
alignment		screws		are
								alignment)
disturbed or the viewfinder
jarred,	the		viewfinder					2
should	remain		aligned
indefinitely.
					Fig. 21: Aligning the Viewfinder.

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Fig. 22: Meade Super Plössl eyepieces.

Tip: If you plan on viewing using higher magnification eyepieces, first locate, center and focus the object using a low-power eyepiece (e.g., 26mm eyepiece). Then remove the lowpower eyepiece and replace it with a higherpower eyepiece; the object should still be centered in the field of view. Objects are much easier to locate and center at lower powers; higher powers are employed simply by changing eyepieces.

Choosing an Eyepiece

The magnification or power, at which a telescope is operating is determined by two factors: the focal length of the telescope and the focal length of the eyepiece.

Telescope Focal Length is the distance that light travels inside the telescope before reaching a focus. In the mirror-lens design of the ETX models, the focal length is compressed by the telescope’s secondary mirror, so that a long focal length is housed in the short ETX optical tube. For example, the ETX-90AT’s focal length is 1250mm or about 49”. This means that if the ETX–90AT were a classical refracting-type of telescope, the optical tube would be more than four feet long instead of the ETX–90AT's compact 11” tube length.

Eyepiece Focal Length is the distance light travels inside the eyepiece before reaching focus. Focal length is usually printed on the side of the eyepiece, for example, 26mm. Low-power eyepieces are typically available in 26mm, 32mm and 40mm sizes (see OPTIONAL ACCESSORIES, page 43). The low-power eyepiece provided with your ETX is designed to provide a wide, comfortable field of view with high image resolution.

Calculating Magnification: On a telescope, such as the ETX, different eyepiece focal lengths are used to achieve different magnifications, from low to high. A 26mm eyepiece yields 48X (“48-power”) on the ETX-90AT, 57X on the ETX-105AT and 73X on the ETX-125AT. A variety of powers may be obtained with the addition of optional eyepieces as well as the #126 2X Barlow Lens which doubles the power of an eyepiece (see OPTIONAL ACCESSORIES, page 43). To calculate magnification, divide the focal length of the telescope’s optical tube by the focal length of the eyepiece. For example:

Telescope Focal Length divided by Eyepiece Focal Length	= Power
1250mm divided by 26mm	= 73X
With Barlow: 73 x 2	= 146X

The eyepiece power or magnification is therefore 73X and 146X with the Barlow.

Most observers should have 3 or 4 eyepieces plus the #126 2X Barlow to achieve the full range of reasonable magnifications possible with ETX models.

Fig. 23a & 23b: Jupiter: Examples of the right amount of magnification and too much magnification.

ETX TIPS

Too Much Power?

Can you ever have too much power? If the type of power you’re referring to is eyepiece magnification, yes, you can! The most common mistake of the beginning observer is to “overpower” a telescope by using high magnifications which the telescope and atmospheric conditions cannot reasonably support. Keep in mind that a smaller, but bright and well-resolved image is far superior to one that is larger, but dim and poorly resolved (see Figs. 23a and 23b). Powers above 300X should be employed only under the steadiest atmospheric conditions.

Autostar can calculate the best eyepiece for you to use. Try out the “Eyepiece Calc” feature in the Utilities menu.

Most observers should have three or four additional eyepieces to achieve the full range of reasonable magnifications possible with the ETX telescopes. See

OPTIONAL ACCESSORIES, page 43.

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Note:

Viewing conditions vary widely from night-to-night and site-to-site. Turbulence in the air, even on an apparently clear night, can distort images. Low-power eyepieces, such as the 26mm supplied with your telescope, are better suited to resolving images in poor viewing conditions.

NEVER point

the telescope directly at or near the Sun at

any time! Observing the Sun, even for the smallest fraction of a second, will result in instant and irreversible eye damage, as well as physical damage to the telescope itself.

Do not look through the telescope's eyepiece or viewfinder while it is rapidly moving. Children should always have adult supervision while observing.

Important Note:

Autostar requests the Country/State, City and Telescope Model information only the first time Autostar is activated. Subsequently, Autostar uses the location and model number you have chosen.

If you wish to change this information, use the "Telescope Model" and "Site" options in the Setup menu. See pages 28, 29 and 31 for more information.

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OBSERVING

Observing by Moving the Telescope Manually

If you wish to observe a distant land object, such as a mountain top or a bird, you can observe by merely pointing the telescope and looking through the eyepiece.

1.Loosen the telescope’s horizontal lock (9, Fig. 1) and vertical lock (6, Fig. 1).

2.Move your telescope to observe distant street signs, mountains, trees and other structures. Use your viewfinder to help sight-in on an object.

3.Center the object in the viewfinder’s crosshairs and then in the telescope eyepiece. When the object is centered in your eyepiece, remember to re-tighten the horizontal and vertical locks.

4.Practice focusing objects using the focus knob (8, Fig. 1).

5.Once you get a feel for how your telescope moves and focuses, try to view something more challenging, like a bird or a distant moving train.

You can also observe stars and objects in the night sky using this method, but note that objects begin to slowly drift across the eyepiece field. This motion is caused by the rotation of the Earth. As you become familiar with the Autostar handbox operation, you can counteract the drift using the automatic tracking feature (see TO TRACK AN OBJECT AUTOMATICALLY, page 17) or by using Autostar's GO TO capabilities (see

GO TO SATURN, page 20).

Terrestrial Observing

ETX telescopes are excellent high-resolution terrestrial (land) telescopes. Viewing terrestrial objects requires looking along the Earth's surface through heat waves. These heat waves often cause degradation of image quality. Lower power eyepieces, like the 26mm, magnify these heat waves less than higher power eyepieces (such as a 9mm eyepiece). Therefore, lower power eyepieces provide a steadier, higher quality image. If the image is fuzzy or ill-defined, reduce to a lower power eyepiece, where the heat waves do not have such an effect on image quality. Observing in early morning hours, before the ground has built up internal heat, produces better viewing conditions than during late afternoon hours.

Observing Using Autostar Arrow Keys

You may observe land and astronomical objects using Autostar's Arrow keys to move the telescope.

1.Tighten the horizontal and vertical locks (9 and 6, Fig. 1).

2.Make sure that Autostar’s coiled cord is connected to the computer control panel’s HBX port (C, Fig. 2).

3.Flip the Power Switch (A, Fig. 2) on the computer control panel to the ON position. A copyright message lights on Autostar’s LCD display, followed by a warning not to look at the Sun. Press the Autostar key prompted by the message when you are done reading. See page 9 to 11 for more information about Autostar’s keys.

4.A “Getting Started” message displays. Press ENTER to skip this message.

5.Keep pressing the ENTER key until "Country/State" displays. (Ignore the prompts requesting "Date" and "Time" for now—these functions will be explained later).

6.When “Country/States” displays, press either one of the SCROLL KEYS to cycle through the choices on the list. When your state or country appears on the list, press ENTER.

7.“Cities” displays. Using the SCROLL KEYS, cycle through the list of cities and press ENTER when your city or the city closest to your observing site displays.

8.Finally “Telescope Models” displays. Using the SCROLL KEYS, cycle through the list of telescope models and press ENTER when your model displays.

9.The display now displays "Setup: Align." .

You can now use the ARROW KEYS to slew (move) the telescope up, down, right or left. Practice using the ARROW KEYS to center objects in the eyepiece.

To change the speed at which the telescope moves (known as the “slew” speed), press a NUMBER KEY from 1 through 9. 1 is the slowest speed and 9 is the fastest. See SLEW SPEEDS on the following page.

Slew Speeds

Autostar has nine slew speeds that move the optical tube at rates that are directly proportional to the sidereal rate and have been calculated to accomplish specific functions. Press the Number key to change the slew speed.

The nine available speeds are:

Number Key 1	=	1x	=	1	x sidereal (0.25 arc-min/sec or 0.004°/sec)
Number Key 2	=	2x	=	2	x sidereal (0.5 arc-min/sec or 0.008°/sec)
Number Key 3	=	8x	=	8	x sidereal (2 arc-min/sec or 0.033°/sec)
Number Key 4	=	16x	=	16	x sidereal (4 arc-min/sec or 0.067°/sec)
Number Key 5	=	64x	=	64	x sidereal (16 arc-min/sec or 0.27°/sec)
Number Key 6	=	128x	=	30	arc-min/sec or 0.5°/sec
Number Key 7	=	1.0° =		60	arc-min/sec or 1.0°/sec
Number Key 8	=	1.5° =		90	arc-min/sec or 1.5°/sec
Number Key 9	=	Max =		approx. 4.5°/sec

Speeds 1, 2 or 3: Best used for fine centering of an object in the field of view of a higher power eyepiece, such as a 9mm eyepiece.

Speeds 4, 5 or 6: Enable centering of an object in the field of a low-to-moderate power eyepiece, such as a 26mm.

Speeds 7 or 8: Best used for rough centering of an object in the viewfinder.

Speed 9: Moves the telescope quickly from one point in the sky to another.

Astronomical Observing

Used as an astronomical instrument, your telescope has many optical and electromechanical capabilities. It is in astronomical applications where the high level of optical performance is readily visible. The range of observable astronomical objects is limited only by the observer’s motivation.

Observe the Moon

Point your telescope at the Moon (note that the Moon is not visible every night) and practice using the Arrow keys and the slew speeds to view different features. The Moon contains many interesting features, including craters, mountain ranges and fault lines. The best time to view the Moon is during its crescent or half phase. Sunlight strikes the Moon at an angle during these periods and adds a depth to the view. No shadows are seen during a full Moon, making the overly bright surface appear flat and rather uninteresting. Try using a neutral density Moon filter when observing the Moon (see OPTIONAL ACCESSORIES, page 43). Not only does it cut down the Moon's bright glare, but it also enhances contrast, providing a more dramatic image.

To Track an Object Automatically

As the Earth rotates beneath the night sky, the stars appear to move from East to West. The speed at which the stars move is called the sidereal rate. You can setup your telescope to move at the sidereal rate so that it automatically tracks (follows) the stars and other objects in the night sky. If the telescope is not tracking an astronomical object, the object will drift out of the eyepiece field of view. The tracking function automatically keeps an object centered in the telescope’s eyepiece.

To automatically track objects, you need to learn how the Autostar keypad operates in order to move through its menus. You'll need to initialize and align your telescope.

Moving Through Autostar’s Menus

The Autostar database is organized in levels for quick and easy navigation.

•Press ENTER to go deeper into Autostar's menu levels.

•Press MODE to move back toward the top menu level.

•Press the Scroll keys to move up and down through the options available for each level.

•Press the Arrow keys to enter characters and digits. The Arrow keys are also used to move the telescope.

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Definition: Initialization is a

procedure that makes sure that Autostar operates correctly. When you first use Autostar, it doesn't yet know where the observation location site is or the time or date of the observation session.

During the alignment procedure, you will enter time, date and observing location

Autostar Uses this information to precisely calculate the location of celestial objects (such as stars and planets) and to move your telescope correctly for various operations.

Tip:

When multiple choices are available within an Autostar Menu option, the current option is usually displayed first and highlighted by a right pointing arrow (>).

Important Note:

Autostar requests the Country/State, City and Telescope Model information only the first time Autostar is activated. Subsequently, Autostar uses the location and model number you have chosen.

If you wish to change this information, use the "Telescope Model" and "Site" options in the Setup menu. See pages 28, 29 and 31 for more information.

Initializing Autostar

This section describes how to initialize Autostar. Perform this procedure the first time you use Autostar or after performing a Reset (see RESET, page 30). Autostar will ask you to enter the current time and date and to choose your observing location and your telescope’s model number from the list it displays.

1.Tighten the vertical and horizontal locks (6 and 9, Fig. 1) if necessary.

2.Make sure that Autostar is connected to the HBX port (C, Fig. 2) of the telescope’s computer control panel.

3.Flip the telescope power switch (A, Fig. 2) to the ON position.

The Autostar screen displays a copyright message, followed by a short beep. Then Autostar takes a few moments to start up the system.

4.A message displays that warns not to look at the Sun. At the end of this message, press the key prompted by Autostar to signify that the message has been read and understood.

5.The Getting Started menu displays a scrolling message. Press ENTER (2, Fig. 4) to bypass the Help tutorial and continue with initialization.

6.Autostar then requests the current date. Use the Number keys (6, Fig. 4) to enter the digits for the date. Use the Arrow keys (5, Fig. 4) to move back and forth from one number to the next in the day display. Next, use the Right Arrow key to move to the month position. Use the Scroll keys (7, Fig. 4) to cycle through the list of months.

When the current month is displayed, use the Right Arrow to move to the year position. Use the Number keys to enter all four digits of the current year. Press ENTER when the entire date has been entered.

7.Autostar then requests the current time. Use the Number keys to enter the time. (Use a "0" for the first digit if it is less than 10.) Use the Arrow keys to move from one number to the next. Press one of the Arrow keys to scroll to "AM" or "PM." If you select the "blank" choice that follows "AM" and "PM," the clock displays time in a 24-hour (military time) format. Press ENTER to start the clock.

8.Autostar then requests the status of Daylight Savings Time. Press a Scroll key to toggle between the YES/NO settings. Select the desired setting by pressing ENTER when the correct setting displays.

Note: Daylight Savings Time may be referred to by a different name in various areas of the world.

9.Autostar then requests the country or state (listed alphabetically) of the observing site. Use the Scroll keys to cycle through the database of countries, states and provinces. Press ENTER when the correct location displays.

10.Autostar then requests the city (listed alphabetically) closest to the observing site. Use the Scroll keys to cycle through the database of cities. Press ENTER when the closest city displays.

11.Autostar then requests the telescope model number. Use the Scroll keys to cycle through the database of models. Press ENTER when your model number displays.

12.System initialization is complete and the screen reads "Setup: Align."

Easy (Two-Star) Align

The fastest and easiest way to locate celestial objects is to use the alt/az Easy Align. Autostar is in the alt/az mode when you first power it on, so you do not need to select this mode, unless you have changed this setting in the Telescope/Mount menu. If you wish to align your telescope in the equatorial (polar) mode, see EQUATORIAL ALIGNMENT, page 51.

Autostar automatically picks two stars from its database for the Easy Align procedure. During this procedure, Autostar moves the telescope to a first alignment star and the user is asked to center the star in the eyepiece. The process is then repeated with a second star to complete the alignment.

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