Instruction Manual

ETX-90EC Astro Telescope ETX-105EC Astro Telescope ETX-125EC Astro Telescope
Meade Instruments Corporation

CONTENTS

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.
Quick-Start Guide.4 Telescope Electronic Controller Functions.5 ETX: Your Personal Window on the Universe.6 Telescope Controls.6 Electronic Controller Functions.8 Getting Started.9 Parts Listing.9 Assembly Instructions.9 Using the Viewfinder.10 Focusing the Viewfinder.10 Aligning the Viewfinder.10 Observation Techniques.11 Choosing an Eyepiece.11 Understanding Magnification.12 Terrestrial Observing.12 Astronomical Observing.13 Sidereal Rate.13 The Electronic Controller.13 Slew Speeds.13 Modes of Operation.14 Telescope Mountings.14 Alt/Az Mode.14 Polar Mode.15 Celestial Coordinates.16 Locating the Celestial Pole.16 Polar Alignment Procedure.16 Photography.18 A Few Tips on Photography.19 Optional Accessories.20 General Maintenance.22 Storage and Transport.22 Inspecting the Optics.23 Troubleshooting.23 Meade Customer Service.24 Telescope Specifications.25 Appendix A: Advanced Controller Functions.26 Tracking Motor Speed.26 Changing Modes.26 Appendix B: Helpful Charts.27 Latitude Chart for Major Cities of the World.27 Star Locator.27 Appendix C: Polar Alignment; Setting Circles.28 Precise Polar Alignment.28 Setting Circles.28 Appendix D: You and the Universe.29 Objects in Space.29 The Moon.29 Planets.29 Deep-Sky Objects.30
CAUTION! Use care to install batteries as indicated by the battery compartment. Follow battery manufacturer's precautions. Do not install batteries backward 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 ETX Astro Telescope for the first time, before a thorough reading of this instruction manual, see the QUICK-START GUIDE on page 4.
The name Meade, the Meade logo, and ETX are trademarks registered with the U.S. Patent Office and in principal countries throughout the world. All rights reserved. 2001 Meade Instruments Corporation.

QUICK-START GUIDE 1 4

Remove the ETX from its packaging and place it on a sturdy surface. Place the eyepiece (A) and viewfinder (B) into their appropriate positions on the telescope and tighten their respective attachment screws to a firm feel only.
Slide the Power Switch (E) on the Computer Control panel to the ON position. The lights flicker on the Electronic Controller. Press any key and the motors briefly move the telescope. The Electronic Controller is now operational.

H Slew Speed: Fast Medium Moderate Slow I D
Securely place the ETX on its side and remove the battery compartment cover (C) from the underside of the drive base. Insert eight (user-supplied) AA-size batteries into the battery compartment (D) in the proper orientation. Replace the cover and return the telescope to an upright position.
Use the Electronic Controller Arrow keys (H) to move the telescope up, down, left, and/or right. To change the telescopes slew speed, press the SPEED key (I). The indicator lights signify the speed, with the upper light showing the highest speed. Each press slows the speed down one level, then cycles back to the highest speed. NOTE: Before observing, verify that the flip-mirror control (14, Fig. 1) is in the up position. See FLIPMIRROR CONTROL, page 7, for more information.
NOTE: The telescope has rotational hard stops in the horizontal and vertical axes to prevent damage to the telescope. See page 6, for more information.
Verify that the Computer Control panel power switch (E) is in the OFF position. Remove the Electronic Controller (F) from the packing materials and plug it into the HBX port (G). Tighten the vertical and horizontal locks (6 and 9, Fig. 1) and then remove the dust cover (19, Fig. 1) from the end of the telescope tube.
Sight along the side of the telescopes main tube to locate an object. Practice using the Electronic Controller Arrow keys to center an object in the telescopes field of view. Use the telescopes focus knob (8, Fig. 1) to bring the object into focus.
TELESCOPE AND ELECTRONIC CONTROLLER FUNCTIONS 4 5
Features of the ETX-90EC, ETX105EC, and ETX-125EC are identical, with the exception of the size of optical tube and the type of viewfinder included as standard equipment.

(on left fork arm)

Fig. 1: The ETX-90EC Astro Telescope.
Fig. 1 (Inset): Computer Control Panel. (A) On/Off switch; (B) Auxiliary ports; (C) Handbox port; (D) 12v connector; (E) Power indicator light.
ETX: Your Personal Window to the Universe
The Meade ETX-90EC, ETX-105EC, and the ETX-125EC are extremely versatile, high-resolution telescopes with features similar to those once available only with larger and more specialized imaging systems. With pushbutton controls, automatic tracking of celestial objects (with one of the optional tripods), 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

An important array of features and manual controls facilitates operation of an ETX telescope. Be sure to become acquainted with all of these controls before attempting observations through the telescope.
Eyepiece - Place the supplied SP 26mm eyepiece into the 90 Eyepiece Holder (4, Fig. 1) and tighten in place with thumbscrew (3, Fig.1). Viewfinder a. b. ETX-90EC: 8 x 21mm Viewfinder: Slide the eyepiece end of the viewfinder through the front of the viewfinder bracket (1, Fig. 5). ETX-105EC, ETX-125EC: 8 x 25mm Right-Angle Viewfinder: Slide the front cell end of the right-angle viewfinder through the rear of the viewfinder bracket (2, Fig. 5).
Eyepiece Holder Thumbscrew - Tightens the eyepiece in place. Tighten to a firm feel only. 90 Eyepiece Holder - Holds the eyepiece upright for easy viewing. 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. 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 Electronic Controller operation. When polar aligned, the vertical lock serves as the Declination, or Dec. lock (see DECLINATION, page 16). 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 with no 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. CAUTION: When loosening the vertical lock, be sure to support the optical tube (5, Fig. 1). The tube may swing downward suddenly and damage the telescope.
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 360 to avoid damage to the internal wiring. The vertical limit stop prevents the viewfinder from contacting the fork mount when the telescope is pointed upward just past 90 and prevents the optical tube from contacting 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.
Focus Knob - Moves the telescopes optical tube (5, Fig. 1) 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-90EC) or 15 ft (ETX-105EC or ETX-125EC) to infinity. Rotate the focus knob clockwise to focus on distant objects, and counterclockwise to focus on nearby objects. 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 Electronic Controller operation. When polar aligned, the horizontal lock serves as the Right Ascension, or R.A. lock (see RIGHT ASCENSION, page 16).

Fig. 2a: Flip mirror control in the up position.
Fig. 2b: Flip mirror control in the down position.
Battery Compartment (not shown, underneath base) - Install eight user-supplied AA batteries in this compartment. See page 9 for more information.
Electronic Controller Functions

Medium Moderate Slow

Fig. 3: Electronic Controller. (1) Arrow Keys; (2) Indicator Lights; (3) SPEED Key; (4) Coil Cord; (5) MODE Key; (6) OUT Key; (7) IN Key. The Electronic Controller provides you with the means to control the telescope motors from a compact handbox. The Electronic Controller (Fig. 3) has soft-touch keys designed to have a positive feel, even through gloves. The primary functions of the Electronic Controller are to move (slew) the telescope to an object, indicate the slew speed, and to operate the optional #1244 (ETX-90EC or ETX-105EC) or #1247 (ETX-125EC) Electric Focuser (see OPTIONAL ACCESSORIES, page 20). Other functions are also possible when using the MODE key. A detailed description of the functions and operation of the Electronic Controller is found in ADVANCED ELECTRONIC CONTROLLER FUNCTIONS, page 26. Arrow Keys (1, Fig. 3): Press one of the four Arrow keys to slew the telescope (i.e., up, down, left, and right) at any one of four slew speeds (see SPEED KEY below). Important Note: If you reverse directions while using the Arrow keys to slew to objects, there may be a slight pause as the telescope motors compensate for the reversal of the internal gears.

Light No.

Light 1 Light 2 Light 3 Light 4

Light Status

On Blinking Off
Indicator Lights (2, Fig. 3): The four red LED (Light Emitting Diode) lights indicate the current slew speed of the telescope. Note: For purposes of this manual, the lights are identified as 1 through 4, with 1 being the top light and 4 being the bottom light.
SPEED Key (3, Fig. 3): Press the SPEED key to change the speed at which the telescope slews to an
Indicator Light Key The procedures in this manual identify the status of the four indicator lights as depicted above: on, blinking, or off.
object. Each press of the SPEED key changes the slew speed to the next slower setting. If the controller is already on the slowest slew speed (light 4), pressing the SPEED key cycles back to the highest speed (light 1). Slew speeds are signified by the indicator lights (2, Fig. 3). Coil Cord: Plug into the HBX connector of the Computer Control Panel.
MODE Key (5, Fig. 3): Press and hold the MODE key to place the Electronic Controller into the Mode
function (see APPENDIX A, page 26).
OUT Key (6, Fig. 3): When using the optional #1244 (ETX-90EC or ETX-105EC) or #1247 (ETX-
125EC) Electric Focuser (see OPTIONAL ACCESSORIES, page 20), press the OUT key to move the focus point outward.
IN Key (7, Fig. 3): When using the optional #1244 (ETX-90EC or ETX-105EC) or #1247 (ETX-125EC)
Electric Focuser (see OPTIONAL ACCESSORIES, page 20), press the IN key to move the focus point inward.

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-90EC 1. Remove the viewfinder by slightly unthreading the six alignment screws (4 and 6, Fig. 6) and slipping it out of the bracket. 2. Loosen the knurled lock-ring (2, Fig. 6) located near the viewfinders front lens cell (1, Fig. 6). Unthread this ring (counterclockwise, as seen from the eyepiece-end 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 viewfinders lens cell. 5. Replace the viewfinder into the viewfinder bracket. Gently tighten the six alignment screws. Proceed with Aligning the Viewfinder. ETX-105EC or ETX-125EC Turn the focus ring (2, Fig. 6) at the base of the viewfinder eyepiece (3, Fig. 6) 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 (6, Fig. 6) 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. - 10 -

ETX-125EC

ETX-90EC
Fig. 6: The Viewfinder. (1) Front lens cell; (2) Knurled lockring (ETX-90EC) or focus ring (ETX-105EC and ETX125EC); (3) Viewfinder eyepiece; (4) Front alignment screws (one not visible in photo); (5) Viewfinder bracket; (6) Rear alignment screws (one not visible).
2. Point the main telescope at some easy-to-find, 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, then tighten the vertical and horizontal locks (6 and 9, Fig. 1) so that the tube cannot move and the object remains centered (1, Fig. 7). 3. While looking through the viewfinder, turn one or more of the three front viewfinder alignment screws (4, Fig. 6), until the crosshairs of the viewfinder point at precisely the same position as the view through the eyepiece of the main telescope (2, Fig. 7).

Slew Speeds

The Electronic Controller has four slew speeds that are directly proportional to the sidereal rate. Press the Speed key to change the slew speed. Note each slew speed corresponds to one of the four LED's of the Electronic Controller.

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Light 1 (top LED): The fastest speed. Use to move the telescope quickly from one point in the sky to another. Light 2: Best for centering an object in the viewfinder. Light 3: Best for centering an object in the field of a low-to-moderate power eyepiece, such as the standard SP 26mm. Light 4: The slowest speed. Use to center an object in the field of view of high-power eyepieces, such as the optional 6.7mm or 12.4mm. The four available speeds are: Light 1 = 1200 x sidereal (300 arc-min/sec or 5/sec) Light 2 = Light 3 = Light 4 = 180 x sidereal (45 arc-min/sec or 0.75/sec) 32 x sidereal (8 arc-min/sec or 0.13/sec) 8 x sidereal (2 arc-min/sec or 0.034/sec)
The two slowest speeds (8x and 32x sidereal) can be used for pushbutton (manual) tracking of astronomical objects while observing through the eyepiece.

Modes of Operation

The Electronic Controller can be set to operate in either of two primary modes: the Alt/Az mode (used when the telescope is operated in the altazimuth configuration; see below) and the polar mode (used when the telescope is polar- (or equatorial) aligned; see page 16). Choose the Alt/Az (altitude-azimuth, or vertical-horizontal) mode for all terrestrial operations of the telescope. In the Alt/Az mode, use the Arrow keys to slew the telescope to terrestrial or astronomical objects and, once you locate them, follow these objects if they move. However, in this mode astronomical tracking is not automatic and requires continuous pushes of the Arrow keys. The Electronic Controller is factory pre-set to the Alt/Az mode. Choose the polar mode when the telescope is equipped with either the optional #880 (ETX90EC) or #881 (ETX-105EC or ETX-125EC) Table Tripod, or #883 Deluxe Field Tripod, for extensive astronomical observations. In this mode use the Arrow keys to slew the telescope to objects. In addition, the telescopes internal motor drive is turned on, enabling the telescope to automatically track celestial objects. You can configure the two screws on the bottom rear of the Electronic Controller handbox to change the default mode of the Electronic Controller to Alt/Az or polar. When in polar mode, you may also set the alignment to the hemisphere in which you are located (not necessary in the Alt-Az mode). Caution: Mode screws A and B are the outer screws in the recess directly under the letters A and B on the rear of the Electronic Controller. Do not remove either of the inner two screws in the recess. Remove mode screw A (1, Fig. 12) to make the Northern hemisphere polar mode the automatic default of the Electronic Controller when power is applied (i.e., the motor drive is activated for operation in the Earths Northern Hemisphere). Remove mode screw B (2, Fig. 12) to make the Southern Hemisphere polar mode the automatic default of the Electronic Controller when power is applied (i.e., the motor drive is activated for operation in the Earths Southern Hemisphere ). Leave both the A and B screws in place (or remove both screws) to keep the telescope in the original factory default Alt/Az mode. Note: Removing either A or B screw affects only the telescopes default mode; you may still make mode changes when desired using the MODE key (see, APPENDIX A, page 26).

configuration the observer does not need to press the Arrow keys of the Electronic Controller in order to track celestial objects. However, the Arrow keys of the Electronic Controller are useful in this configuration to enable the centering of objects within the telescopic field or, for example, to move the telescope over the surface of the Moon or through a large star field.

Celestial Coordinates

Before polar aligning your ETX model, it is helpful to understand how to locate celestial objects as they move across the sky. A celestial coordinate system was created that maps an imaginary sphere surrounding the Earth upon which all stars appear to be placed. This mapping system is similar to the system of latitude and longitude on Earth surface maps. In mapping the surface of the Earth, lines of longitude are drawn between the North and South Poles and lines of latitude are drawn in an East-West direction, parallel to the Earths equator. Similarly, imaginary lines have been drawn to form a latitude and longitude grid for the celestial sphere. These lines are known as Right Ascension and Declination. The celestial map also contains two poles and an equator just like a map of the Earth. The poles of this coordinate system are defined as those two points where the Earths north and south poles (i.e., the Earth's axis), if extended to infinity, would cross the celestial sphere. Thus, the North Celestial Pole (1, Fig. 13) is that point in the sky where an extension of the North Pole intersects the celestial sphere. The North Star, Polaris is located very near the North Celestial Pole (1, Fig. 13). The celestial equator (2, Fig. 13) is a projection of the Earths equator onto the celestial sphere. So just as an object's position on the Earths surface can be located by its latitude and longitude, celestial objects may also be located using Right Ascension and Declination. For example, you could locate Los Angeles, California, by its latitude (+34) and longitude (118). Similarly, you could locate the Ring Nebula (M57) by its Right Ascension (18hr) and its Declination (+33). Right Ascension (R.A.): This celestial version of longitude is measured in units of hours (hr), minutes (min), and seconds (sec) on a 24-hour "clock" (similar to how Earth's time zones are determined by longitude lines). The "zero" line was arbitrarily chosen to pass through the constellation Pegasus a sort of cosmic Greenwich meridian. R.A. coordinates range from 0hr 0min 0sec to 23hr 59min 59sec. There are 24 primary lines of R.A., located at 15-degree intervals along the celestial equator. Objects located further and further East of the zero R.A. grid line (0hr 0min 0sec) carry higher R.A. coordinates. Declination (Dec.): This celestial version of latitude is measured in degrees, arc-minutes, and arcseconds (e.g., 15 27' 33"). Dec. locations north of the celestial equator are indicated with a plus (+) sign (e.g., the Dec. of the North celestial pole is +90). Dec. locations south of the celestial equator are indicated with a minus () sign (e.g., the Dec. of the South celestial pole is 90). Any point on the celestial equator (such as the the constellations of Orion, Virgo, and Aquarius) is said to have a Declination of zero, shown as 0 0' 0."

Fig. 20: Example of a format 2 photo.

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OPTIONAL ACCESSORIES
A wide assortment of professional Meade accessories are available for the for ETX telescopes. Meade accessories greatly extend many important applications to the telescope, from low-power, wide-field terrestrial viewing to high-power lunar and planetary observing. The premium quality of these accessories is well-suited to the quality of the instrument itself. Meade telescopes and accessories, including optional accessories for ETX telescopes, are available at more than 3,000 dealer locations in the U.S. and Canada and through Meade international distributors worldwide. Once you have identified the accessories you wish to order, contact your local Meade authorized dealer. To find a dealer near you call (949) 451-1450 or visit the Meade website at www.meade.com. #497 Autostar Computer Controller: One of the most important advances in telescope control in the past 25 years, the Meade #497 Autostar Computer Controller (Fig. 21) turns your ETX model into an automatic celestial object locating system. Just plug Autostar into the telescopes HBX port in place of the standard-equipment Electronic Controller, do a quick telescope alignment, and you are ready to observe any object in the Autostars 14,000-object database. Fig. 21: #497 Autostar Computer Controller. Best of all, the Meade Autostar is easy to use. Even the most novice observer will locate dozens of fascinating celestial objects the very first night out from commonly observed objects, such as the rings of Saturn, the satellites of Jupiter, and the Orion Nebula (M42), to more difficult objects, such as the Ring Nebula (M57) in Lyra, the Spiral Galaxy (M33) in Triangulum, and the Sombrero Galaxy (M104) in Virgo; to very obscure objects near the telescopes threshold of visibility, such as spiral galaxy NGC 3310 in Ursa Major. Any of Autostars database objects can be called up and entered on the hand controller display in seconds. The observer then simply presses the GO TO pushbutton and watches as the telescope automatically slews to the object and places it in the field of view. Autostar brings into easy access objects that were previously unreachable for all but the most dedicated of amateur astronomers. AstroFinder Software/#505 Cable Connector Kit: With Meade AstroFinder software (Fig. 22) loaded into your PC, Autostar-equipped ETX90EC, ETX-105EC, and ETX-125EC telescopes may be remotely controlled from the PC display. The #505 Cable Connector Set, permitting connection of ETX, Autostar, and PC, is included with each AstroFinder package. Eyepieces: For higher and lower magnifications, Meade Super Plssl (SP) and Super Wide Angle (SWA) eyepieces (Fig. 23), as well as the Series 4000 8mm to 24mm Zoom eyepiece, yield high-resolution imaging with all ETX telescope models. A useful selection includes the SP 9.7mm, SP 12.4mm, and SWA 18mm. Under good seeing conditions, Meade Ultra Wide Angle 4.7mm and 6.7mm eyepieces present the widest obtainable fields of view at high powers and are well suited for observing the Moon and planets. Alternative optional eyepieces may be chosen from the Meade Series 3000 Plssl eyepieces. Powers obtained with each eyepiece are shown in the following table. ETX-90EC Power 2x Barlow 195X 129X 101X 83X 63X 48X 39X 31X 91X 69X 51X 266X 187X 390X 258X 202X 166X 126X 96X 78X 62X 182X 138X 102X N/A 374X ** ETX-105EC ETX-125EC Power 2x Barlow Power 2x Barlow N/A 439** 297X 196X 153X 127X 95X 73X 59X 48X 138X 106X 78X 404X 284X 594X** 392X 306X 253X 190X 146X 119X 96X 275X 211X 155X N/A 567X**

Storage and Transport

When the telescope is not in use, store it in a cool, dry place. Do not expose the instrument to excessive heat or moisture. It is best to store the telescope in its original box with the vertical and horizontal locks (6 and 9, Fig. 1) in the unlocked positions. If shipping the telescope, use the original box and packing material to protect the telescope during shipment. When transporting the telescope, take care not to bump or drop the instrument; this type of abuse can damage the optical tube and/or the objective lens, and knock the optics out of alignment. It is highly recommended to use an optional carry case to transport the telescope (see OPTIONAL ACCESSORIES, page 21).

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Inspecting the Optics
A Note About the Flashlight Test:" If a flashlight or other high-intensity light source is pointed down the main telescope tube, the view (depending upon the observers line of sight and the angle of the light) may reveal what appear to be scratches, dark or bright spots, or uneven coatings, giving the appearance of poor quality optics. These effects are only seen when a high intensity light is transmitted through lenses or reflected off the mirrors, and can be seen on any high-quality optical system, including giant research telescopes. The optical quality of a telescope cannot be judged by the flashlight test; the true test of optical quality can only be conducted through careful star testing.

Troubleshooting

The following suggestions may be helpful with operation of the ETX-90EC, ETX-105EC, and ETX-125EC.
The power indicator light on the telescope does not come on or there is no response when pressing the Electronic Controller Arrow keys:
Verify that the Computer Control panel power switch (10A, Fig. 1) is in the ON position. Verify that the Electronic Controller cord (4, Fig. 3) is firmly connected to the HBX port (10C, Fig. 1). If using internal power (batteries), verify that the batteries are installed correctly and that they have sufficient charge (see ASSEMBLY INSTRUCTIONS, page 9). Note: If the batteries are getting low on charge, there will be a marked difference in the slew speed. The speed indicator lights may also flash and the speed may change. If any of these symptoms occurs, turn the power off and replace the batteries. If using an external power source, verify that it is properly connected between the 12-volt connector (10D, Fig. 1) and either a wall plug (AC source) or a car cigarette lighter (DC source). If the Electronic Controller does not respond to commands, move the power switch to OFF and then back to ON. If the telescope does not slew after power is applied or if the motor quits or stalls, verify that there are no physical obstructions that would impede telescope movement. If all physical obstacles are removed and the telescope still does not move properly, turn off the power and unplug the Electronic Controller. Plug the Electronic Controller back in and turn the power back on.

Unable to see an image through the eyepiece:
Confirm that the lens cover has been removed from the telescope. Confirm that the flip-mirror control (14, Fig. 1) is in the up position if using the eyepiece holder (4, Fig. 1) so that light is directed to the eyepiece (1, Fig. 1). Confirm that the flip-mirror control is in the down position if using the #932 Erecting Prism or doing photography with an ETX model (see TELESCOPE CONTROLS, page 6 and PHOTOGRAPHY, page 18).
Object appears in the viewfinder but not in the eyepiece:
The viewfinder is not properly aligned with the telescope (see ALIGNING THE VIEWFINDER, page 10).
Slew speed does not change when you press the SPEED key, or the telescope moves slowly even though the fast slew speed is chosen:
Verify that only one light is illuminated on the Electronic Controller. If more than one light is on or blinking, the Mode function is active. Exit the Mode function by pressing and holding the MODE key until only one light is on (see APPENDIX A, page 26). The battery power may be low (see ASSEMBLY INSTRUCTIONS, page 9).
Telescope does not track a celestial object:
The telescope tracks celestial objects automatically only if it is placed in the polar mode (see APPENDIX A, page 26) and the telescope is polar aligned (see POLAR ALIGNMENT, page 16) using the #880 (ETX-90EC), #881 (ETX-105EC or ETX-125EC) Table Tripod, or #883 Deluxe Field Tripod (see OPTIONAL ACCESSORIES, page 21). The more accurate the polar alignment, the longer the telescopes motor drive holds an object in the field of view of the eyepiece. If using the Alt/Az mode, track celestial objects by using the Arrow keys on the Electronic Controller. Automatic tracking of objects in the Alt/Az mode requires the optional #497 Autostar Computer Controller. Also the Horizontal and Vertical locks must be locked (page 6).
Images through the eyepiece appear unfocused or distorted:
The magnification may be too high for the viewing conditions. Back off to a lower power eyepiece (see UNDERSTANDING MAGNIFICATION, page 12).

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If inside a warm house or building, move outside. Interior air conditions may distort terrestrial or celestial images, making it difficult, if not impossible, to obtain a sharp focus. For optimal viewing, use the telescope outside in the open air instead of observing through an open or closed window or screen. If viewing a land object on a warm day, heat waves will distort the image (see TERRESTRIAL OBSERVING, page 12). For clear viewing of objects, turn the focus knob (8, Fig. 1) slowly since the in-focus point of a telescope is precise. Turning the focus knob too quickly may cause the focus point to pass without notice. The optics within the telescope need time to adjust to the outside ambient temperature to provide the sharpest image. To cool down the optics, set the telescope outside for 10 to 15 minutes before observing begins.

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Appendix B: HELPFUL CHARTS
Latitude Chart for Major Cities of the World
To aid in the polar alignment procedure (see page 16), latitudes of major cities around the world are listed below. To determine the latitude of an observing site not listed on the chart, locate the city closest to your site. Then follow the procedure below: Northern hemisphere observers (N): If the site is over 70 miles (110 km) north of the listed city, add one degree for every 70 miles. If the site is over 70 miles South of the listed city, subtract one degree per 70 miles. Southern Hemisphere observers (S): If the site is over 70 miles (110 km) north of the listed city, subtract one degree for every 70 miles. If the site is over 70 miles South of the listed city, add one degree per 70 miles. NORTH AMERICA

Star Locator

Following is a list of bright stars with their R.A. and Dec. coordinates, along with the Northern hemisphere season when these stars are prominent in the night sky. This list will aid the observer to find alignment stars at various times of the year. For example, if it is a midsummer evening in the Northern hemisphere, Deneb in the constellation Cygnus, would be an excellent alignment star, while Betelgeuse could not be used because it is in the winter constellation Orion and thus below the horizon. Season Spring Spring Spring Summer Summer Summer Summer Fall Fall Fall Winter Winter Winter Winter Star Name Arcturus Regulus Spica Vega Deneb Altair Antares Markab Fomalhaut Mira Rigel Betelgeuse Sirius Aldebaran Constellation Botes Leo Virgo Lyra Cygnus Aquila Scorpius R.A. Dec.
14h16m 19 11" 10h09m 11 58" 13h25m -11 10" 18h37m 20h41m 19h51m 16h30m 38 47" 45 17" 08 52" -26 26"
Albuquerque Anchorage Atlanta Boston Calgary Chicago Cleveland Dallas Denver Detroit Honolulu Jackson Kansas City Kenosha Las Vegas Little Rock Los Angeles Mexico City Miami Minneapolis Nashville New Orleans New York Oklahoma City Ottawa Philadelphia Phoenix Portland Salt Lake City San Antonio San Diego San Francisco Seattle Washington EUROPE
State/Prov./Country Latitude
New Mexico Alaska Georgia Massachusetts Alberta Illinois Ohio Texas Colorado Michigan Hawaii Mississippi Missouri Wisconsin Nevada Arkansas California Mexico Florida Minnesota Tennessee Louisiana New York Oklahoma Ontario Pennsylvania Arizona Oregon Utah Texas California California Washington District of Columbia N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N

Setting Circles

The ETX models are equipped with R.A. and Dec. setting circles (13 and 16, Fig. 1) to aid in locating faint celestial objects when the telescope has been polar aligned. Setting circles emulate the celestial coordinates found on star charts or in sky catalogs. Any charted object is easily located by coordinates in R.A. (in hours, minutes, and seconds, from 0h 0m 0s to 23h 59m 59s) and Dec. (in degrees from 0 to 90). With an ETX model polar aligned, use the Electronic Controller Arrow keys (1, Fig. 3) to move the telescope in R.A. (left and right keys) and Dec. (up and down keys). Note: The Dec. setting circle is located on the left arm of the telescope fork mount. The right arm of the mount contains a graduated circle (mounted behind the knurled knob of the vertical lock), without Dec. numbers. Declination Setting Circle: The Dec. setting circle (Fig. 31) has been factory set to read the correct Declination of celestial objects.
Fig. 31: Section of Declination setting circle.
Fig. 32: Section of Right Ascension setting circle.
Because the smooth knob on this fork mount arm need never be loosened, the Dec. setting circle should always remain calibrated. If for some reason this knob becomes loose and the Dec. setting circle must be recalibrated, level the optical tube (5, Fig. 1) so that it is parallel to the drive base. Loosen the smooth knob covering the Dec. setting circle until the setting circle moves freely. Reposition the setting circle so that the 0 setting aligns with the Dec. pointer (5, Fig. 16). Retighten the Dec. knob. Right Ascension Setting Circle: Since celestial objects move in R.A., the R.A. setting circle (Fig. 32) must be reset as each object is located during an observing session. The R.A. pointer is located on the drive base 90 counterclockwise from the telescopes Computer Control panel (10, Fig. 1) immediately under the R.A. circle.
Note: The R.A. circle has two rows of numbers from 0 to 23, corresponding to the hours of a 24-hour clock. The upper row of numbers is used by observers in the Earths Northern Hemisphere, the lower row by observers in the Earths Southern Hemisphere.
To use the setting circles to find astronomical objects, the ETX must first be polar aligned. It is advisable that the motor drive be turned on (see APPENDIX A, page 26) and that a low-power eyepiece (e.g., the SP 26mm eyepiece) be employed. Then use the following procedure: 1. Identify the celestial coordinates (R.A. and Dec.) of a bright, easy-to-find object, such as a bright star. (Avoid using Polaris or any object near Polaris.) Coordinates of bright stars are listed in the STAR LOCATOR, page 27, astronomy magazines, text books, or star charts. Center this object in the telescopes field of view. 2. Manually turn the R.A. circle (13, Fig. 1) to read the R.A. of the object at the R.A. pointer (7, Fig. 16). 3. The R.A. circle is now calibrated to read the correct R.A. of any object at which the telescope is pointed. The Dec. circle is already calibrated through polar alignment. 4. To find another object, again identify the R.A. and Dec. coordinates. Then, without touching the setting circles, move the telescope (manually, by unlocking the vertical and horizontal locks, or by slewing the telescope using the Electronic Controller Arrow keys) so that the R.A. and Dec. pointers read the coordinates of the second object. 5. If the above procedure has been followed carefully, the second object will now be in the telescopes field of view. Note: Since the second object (i.e., the object to be located) is in constant motion, once the R.A. circle is calibrated (step 2, above) the telescope should be moved rapidly to read the coordinates of the second object. Otherwise the second object will no longer be in the position indicated by the R.A. circle. Using setting circles requires a developed technique. When using the circles for the first time, try hopping from one bright star (the calibration star) to another bright star of known coordinates. Practice moving the telescope from one easy-to-find object to another. In this way the precision required for accurate object location becomes familiar.

Fig. 33: The Moon. Note the deep shadows in the craters.

Planets

Planets change positions in the sky as they orbit around the Sun. To locate the planets on a given day or month, consult a monthly astronomy magazine, such as Sky and Telescope or Astronomy. Listed below are the best planets for viewing through your ETX model telescope. Venus is about nine-tenths the diameter of Earth. As Venus orbits the Sun, observers can see it go through phases (crescent, half, and full) much like those of the Moon. The disk of Venus appears white, as sunlight is reflected off the thick cloud cover that completely obscures any surface detail. Mars is about half the diameter of Earth. Through the telescope it appears as a tiny reddish-orange disk. You may see a hint of white at one of the planets polar ice caps. Approximately every two years, when Mars is closest to Earth, additional detail and coloring on the planet's surface may be visible.

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Fig. 34: Jupiter and its four largest moons. The moons can be observed in a different position every night.
Jupiter (Fig. 34) is the largest planet in our solar system, with a diameter 11 times that of Earth. Jupiter appears as a disk with dark lines stretching across the surface. These lines are cloud bands in the atmosphere. Four of Jupiters 29 (and still counting!) moons (Io, Europa, Ganymede, and Callisto) can be seen as star-like points of light when you use even the lowest magnification. The number of moons visible on any given night changes as they circle around the giant planet. Saturn (Fig. 35) is nine times the diameter of Earth and appears as a small, round disk with rings extending out from either side. In 1610, Galileo, the first person to observe Saturn through a telescope, did not understand that what he was seeing were rings. Instead, he believed that Saturn had ears. Saturns rings are composed of billions of ice particles. The major division in Saturn's rings, called the Cassini Division, is generally visible through all three ETX models. Titan, the largest of Saturns moons, can also be seen as a bright, star-like object near the planet.

Operating Instructions

Meade #884 Deluxe Field Tripod
For use with all ETX telescopes

Introduction

The Meade #884 Tripod allows an ETX telescope to be mounted in either the altazimuth or the equatorial mode. The assembly includes a latitude adjustment control and a tilt-plate incorporated into the design. Parts List Tripod (1) with attached tilt-plate (2) and latitude adjustment control (3) with latch (4). Two attachment knobs (5) for attaching an ETX telescope to the tilt-plate. Spreader tray (6). Separate spring, two washers, and tension knob (7) to attach tray to tripod. Three leg extension lock knobs (8). How to assemble the tripod
Step 1: Spread the tripod (1) legs apart to a fully open position.
Step 2: Slide the spreader tray (6) onto the central threaded rod.
Step 3: Slide a washer, followed by the spring, another washer, and the tension knob (7) onto the threaded rod. Tighten the tension knob to a firm feel.
Step 4: Adjust the height of the tripod by loosening the leg lock knobs (8) and adjusting the height of the inner leg exten-sions. Then retighten the lock knobs.
Note: It is not necessary to tighten the spring (Step 3) to a fully compressed position. Tighten until the spreader tray holds the legs tightly without slipping.

Mounting your Telescope

As the Earth rotates on its axis, astronomical objects appear to move across the sky in an arc. This apparent motion is not obvious to the unaided eye, but when viewed through a telescope such as an ETX, this motion is rapid indeed. If the motor drive has not been engaged, celestial objects viewed in the telescope eyepiece drift entirely out of the field of view in 15 to 60 seconds, depending on the magnification employed. However, by mounting your telescope and turning on the motor drive, you can counteract the drift of objects in the eyepiece. The two basic types of mounting are: altazimuth (alt/az) and equatorial. It is unnecessary for ETX owners who use an Autostar Controller to equatorially mount the telescope. The Autostar Controller allows the telescope to be mounted in the altazimuth (alt/az) mode for all observing purposes. If you are using the ETX-70AT: Skip the "Equatorial Mount" section, below, and follow the procedure described in the section entitled "Altazimuth (Alt/Az) Mount." If you are using the ETX-90/105/125 equipped with the optional Autostar hand controller: Skip the "Equatorial Mount" section, below, and follow the procedure described in the "Altazimuth Alt/Az Mount" section. If you are using the ETX-90/105/125EC with Electronic Controller (EC): Follow the procedures in the "Equatorial Mount" section and skip the section entitled "Altazimuth (Alt/Az) Mount." If you are using the ETX-90RA: Follow the procedures in the "Equatorial Mount" section and skip the section entitled "Altazimuth (Alt/Az) Mount." Equatorial Mount If you are using the Electronic Controller, use equatorial mounting. Mounting the telescope in this configuration lines up the telescope's polar axis with the North Celestial Pole (or the South Celestial Pole if observing in the southern hemisphere). When using an equatorially mounted telescope, tracking (following) celestial objects is possible by turning on your ETX telescope's motor drive. The motor counteracts the Earth's rotation and keeps objects in the field of view of the eyepiece for hands-off tracking.

Equatorial Mounting Procedure 1. Loosen the latitude control latch (4, Fig. 1) and lift up the tilt-plate (2, Fig. 1) 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. (See Fig. 1.) 2. Turn the tripod, so that the face of the tilt-plate points North (Figs. 7 and 8). If you attach the telescope to the tripod indoors, be sure to orient the face of the tilt-plate to point North after moving the telescope outdoors. Equivalently, point the tripod leg (9, Fig. 7) North. This is the leg opposite from the latitude control bar (3, Fig. 7). ETX-90RA model: Line up the two mounting holes of your telescope over the attachment knobs (5, Fig. 3). Thread the attachment knobs into the base of the telescope. Tighten to a firm-feel only. Important Note about the ETX-90RA model: The On/Off switch is located on the base of the drive base. This switch must be turned on before the telescope is mounted to the tilt-plate. ETX-90EC, ETX-105EC, and ETX-125EC models with Electronic Controller (EC): Line up the mounting hole on the base of the telescope labeled "High Latitude Leg" with the attachment knob that is closest to the latitude control bar (see Fig. 2). Line up the other mounting hole with the remaining attachment knob. Thread both attachment knobs into the base of the telescope. Tighten to a firm-feel only. (See Fig. 3.) 4. Determine the latitude of your observing location from a road map, atlas, or the LATITUDE CHART FOR MAJOR CITIES OF THE WORLD, provided in your ETX manual. Loosen the latitude control latch (4, Fig. 4) and adjust the latitude control bar (3, Fig. 4) so that your observing site's latitude is just visible above the flat surface of the tripod head. Retighten the latch. (See Fig. 4.) If you have not already done so, orient the tripod leg (9, Fig. 7) so that it is pointing due North (if the location of Polaris, the North Star, is known, point the telescope directly at Polaris. Observers located in the Earths Southern Hemisphere must point the telescope due South). (See Figs. 7 and 8.) The telescope is now equatorially mounted; the tripod must not be moved, or else the alignment will be lost. Instead, use one of the following methods to move the telescope's optical tube to a desired celestial object. (a) Loosen the Horizontal (R.A.) and/or Vertical (Dec.) locks (see your telescope Operating Instructions) to permit the optical tube to be freely moved manually. Tighten the locks once you center on the object. (b) With the Horizontal and Vertical locks in their locked positions, use the manual slow-motion controls (ETX-90RA models) or the Arrow keys of the Electronic Controller (ETX-90EC, ETX-105EC, and ETX-125EC models) to move the optical tube. Note: For most astronomical observing requirements, approximate settings of the telescope's latitude and North-pointing tripod leg (steps 4 and 5, above) are acceptable. Do not allow undue attention to precise equatorial mounting of the telescope to interfere with your enjoyment of the instrument. Using an Equatorially Mounted Telescope Once your telescope is equatorially mounted, the telescope motor drive will keep a celestial object in the telescope eyepiece's field of view. To activate the tracking feature: 1. 2. Center a celestial object in the eyepiece. See the appropriate section in your telescope's operating instructions for more information about locating celestial objects. Activate your telescope's motor drive. The telescope now tracks the centered object. ETX-90RA models: The On/Off switch is located on the base of the drive base. This switch must be turned on before the telescope is mounted to the tilt-plate. The telescope will automatically track astronomical objects: see the telescope's operating instructions for details in this regard. Use the telescope's manual slow motion controls to make minor adjustments to keep an object centered. ETX-90EC, ETX-105EC, and ETX-125EC models with Electronic Controllers: The On/Off switch is located on the telescope's Computer Control panel. The telescope will automatically track astronomical objects; see the telescope's operating instructions for details in this regard. Use the Electronic Controller's Arrow keys to make minor adjustments to keep the object centered.

Fig. 1: Loosen control latch (4).
High latitude leg mounting hole. Attachment knob.

Latitude control bar.

Fig. 2: High latitude leg mounting hole and corresponding attachment knob.
Fig. 3: Attach telescope to tripod.

Fig. 4: Set latitude.

Note: If your telescope does not begin tracking when you activate the motor drive (you should hearing a "whirring" sound), check the configuration of the "mode screws" on the back of the Electronic Controller. See "Modes of Operation" in your telescope's operating instructions for more information. Caution: Do not move the tripod or adjust the latitude setting while observing, or the mounting alignment will be lost. Note: The telescope's motor drive disengages when the Horizontal and the Vertical lock levers are unlocked and re-engages when the levers are relocked. 3. At the end of an observing session, remember to turn off the motor drive.
Altazimuth (Alt/Az) Mount Ideal for both terrestrial applications and also for astronomical observation with Autostar. Altazimuth (alt/az) mounting (from "altitude" meaning vertical and "azimuth" meaning horizontal) permits movement of the telescope tube in both the vertical (altitude) and the horizontal (azimuth) directions. To mount your telescope in the alt/az mode: 1. Loosen the latitude control latch (4, Fig. 1) and lift up the tilt-plate (2, Fig. 1) 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. (See Fig. 1.) 2. ETX-70AT model: Line up the two mounting holes of your telescope over the attachment knobs (5, Fig. 3). Thread the attachment knobs into the base of the telescope. Tighten to a firm feel only. ETX-90EC, ETX-105EC, and ETX-125 models with Autostar: Line up the mounting hole on the base of the telescope marked "High Latitude Leg" with the attachment knob that is closest to the latitude control bar (see Fig. 2). 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. 3.) Unlock the latitude control latch (4, Fig. 4) 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. (See Fig. 6.)

Using an Alt/Az Mounted telescope The telescope is now altazimuth mounted on the #884 Tripod. Motions of the telescope may be effected in either horizontal or vertical directions. ETX telescopes equipped with an Autostar hand controller (standard equipment with the ETX-70AT: optionally available for the ETX-90EC, ETX-105EC, and ETX-125EC) may be used in the altazimuth mode, and the Autostar hand controller directs the telescope to track astronomical objects in both vertical and horizontal directions, simultaneously. Note that in the case of altazimuth mounting, the orientation of the tripod is irrelevant: the tripod may be placed on the ground with tripod legs pointing in arbitrary directions. For information on the use of your ETX telescope equipped with an Autostar hand controller, consult your telescope's operating instructions.

North Celestial Pole

Fig. 6: Altazimuth Alignment. Note that the tilt-plate is level.
Fig. 7: Example of Polar Alignment. Note that the face of the tilt-plate points North.
Fig. 8: Example of Polar Alignment. Note that the face of the tilt-plate points North.
Locating the Celestial Pole
Using the North Star (Polaris) to find North is useful in equatorial mounting. Polaris is the tail star of the Little Dipper; however, the Little Dipper is made up of dim stars and is not always easily located. A simple way of locating Polaris is to draw an imaginary line from the so-called "pointer" stars of the Big Dipper to Polaris (see diagram below). In the Southern hemisphere, locate South by using the faint star Sigma Octantis (the South Star).

Little Dipper

Polaris

Big Dipper

Fig. 9: Locating Polaris.

Cassiopeia

If you have a question concerning use of the Meade #884 Deluxe Field Tripod, call the Meade Instruments Customer Service Department at (949) 451-1450, or fax to (949) 451-1460. Customer Service hours are 8:30 AM to 4:30 PM, Pacific Time, Monday through Friday.

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Meade Instruments Corporation
Worlds Leading Manufacturer of Astronomical Telescopes for the Serious Amateur
6001 Oak Canyon, Irvine, California 92618 I (949) 451-1450 FAX: (949) 451-1460 I www.meade.com

Part no. 14-0269-00

Ver. 6-02