Instruction Manual

8" LX90 Schmidt-Cassegrain Telescope

AutoStar LNT SmartFinder

The Meade Schmidt-Cassegrain Optical System
(2) (1) Ray (2) Ray (1) (2) (1) Focal Plane Secondary Mirror Primary Baffle Tube Field Stops Primary Mirror Correcting Plate Secondary Baffle (1) (2)
In the Schmidt-Cassegrain design of the Meade LX90, light enters from the right, passes through a thin lens with 2-sided aspheric correction (correcting plate), proceeds to a spherical primary mirror, and then to a convex secondary mirror. The convex secondary mirror multiplies the effective focal length of the primary mirror and results in a focus at the focal plane, with light passing through a central perforation in the primary mirror. The Meade 8" LX90 Schmidt-Cassegrain includes an oversize primary mirror of an 8.25" diameter, yielding a fully illuminated field-of-view significantly wider than is possible with a standard-size primary mirror. Note that light ray (2) in the figure would be lost entirely, except for the oversize primary. It is this phenomenon which results in Meade SchmidtCassegrains having off-axis field illuminations about 10% greater, aperture-for-aperture, than other Schmidt-Cassegrains utilizing standard-size primary mirrors. Field stops machined into the inside-diameter surface of the primary mirror baffle tube significantly increase lunar, planetary, and deep-space image contrast. These field stops effectively block off-axis stray light rays.

CONTENTS

WARNING!
Never use a Meade LX90 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 at or near the Sun. Do not look through the telescope or SmartFinder as it is moving. Children should always have adult supervision while observing.
Quick-Start Guide... 4 Telescope Features.. 6 AutoStar Features... 9 Getting Started..12 Parts Listing..12 How to Attach the Tripod to the Telescope.12 How to Assemble Your Telescope..12 Choosing an Eyepiece...14 Using SmartFinder..14 Aligning SmartFinder and the Viewfinder.15 Observing...16 Observing By Moving the Telescope Manually.16 Terrestrial Observing..16 Observing Using AutoStar's Arrow Keys.16 Slew Speeds..17 Observe the Moon..17 Astronomical Observing..18 To Track an Object Automatically..18 Alt/Az Home Position..18 Moving Through AutoStars Menus..18 Initializing AutoStar...18 Observe a Star Using Automatic Tracking..19 Automatic Alignment..19 Go To Saturn..20 Using the Guided Tour...20 Basic AutoStar Operation...21 AutoStar Navigation Exercise..21 Entering Data into AutoStar..22 Navigating AutoStar..22 Menus and Menu Options...23 Complete AutoStar Menu Structure.23 Objects Menu..24 Event Menu..25 Glossary Menu...25 Utilities Menu..25 Setup Menu..27 Advanced AutoStar Features..30 Adding Observing Sites..30 Finding Objects Not in the Database.31 Observing Satellites..32 How to Create Your Own Guided Tour..33 Landmarks...36 Identify...37 Advanced Alt/Az Alignment..37 Browse...38 Photography with the LX90..39 Optional Accessories..41 Maintenance...43 Collimation...43 Inspecting the Optics..44 Gauging the Movement of the Telescope.44 Meade Customer Service.44 Specifications..45 Appendix A: Equatorial (Polar) Alignment..46 Appendix B: Helpful Charts..52 Appendix C: Training the Drive..53 Appendix D: Changing the LNT Modules Battery..54 Appendix E: Basic Astronomy..55
CAUTION: Use care to install batteries in the orientation indicated by illustration in the battery slots of the battery holder. 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.

GETTING STARTED

Getting the telescope ready for first observations requires only a few minutes. When first opening the packing box, note carefully the following parts: LX90 Telescope with fork mount system and attached SmartFinder AutoStar handbox and interface coil cord Eyepiece holder and 1.25 diagonal prism 8 x 50 Viewfinder Super Plssl 26mm eyepiece Variable height tripod and mounting base Set of hex wrenches and a plastic bag containing a C clip and a washer
How to Attach the Tripod to the Telescope Assembly
The telescopes fork mount attaches directly to the field tripod. The telescope in this way is mounted in an Altazimuth (Altitude-Azimuth, or vertical-horizontal) format. The telescope in this configuration moves along vertical and horizontal axes, corresponding respectively to the Declination (vertical) and Right Ascension (horizontal) axes in an astronomical observing mode. The field tripod also can be used in conjunction with the optional equatorial wedge (see "EQUATORIAL WEDGE," page 49) for long exposure astrophotography. The equatorial wedge permits alignment of the telescopes Polar Axis with the Celestial Pole (or North Star). 1. After removing the field tripod from its shipping carton, stand the tripod vertically, with the tripod feet down and with the tripod still fully collapsed (see Fig. 3). Grasp two of the tripod legs and, with the full weight of the tripod on the third leg, gently pull the legs apart to a fully open position. Thread in the 6 lock-knobs (2 on each tripod leg) near the foot of each tripod leg (Fig. 3). These lock-knobs are used to fix the height of the inner, extendible tripod leg sections. NOTE: Tightening to a firm-feel is sufficient; over-tightening may result in stripping of the knob threads or damage to the tripod legs and results in no additional strength. The spreader bar (4, Fig. 3) has been removed for shipment. To install, first remove the threaded rod (2, Fig.3) from the tripod head (1, Fig. 3); a small piece of plastic holds the threaded rod in place. Remove the small plastic bag that is stapled to the threaded rod. This bag contains the C clip retainer and an extra clip. Slide the washer followed by the spreader bar onto the threaded rod (note the correct orientation as shown in Fig. 4) and position the threaded rod back through the tripod head. Place the clip retainer ( a C clip) into the slot in the threaded rod. This clip holds the threaded rod in place. See Fig. 3. Position the spreader bar so that the 3 arms of the spreader bar line up with the 3 tripod legs.

Fig. 6: SmartFinder Location.
Fig. 6b: Turn the top (2) or side (3) SmartFinder.

Aligning the Viewfinder

Like the SmartFinder, the viewfinder helps you locate objects and must also be aligned to the main telescope. To align the viewfinder, perform steps 1 through 5 during the daytime; perform step 6 at night. 1. Slide the track on the bottom of the viewfinder into the slot in the viewfinder mounting assembly. See Fig. 7a. To secure the viewfinder to the mounting assembly, tighten the two thumbscrews (Fig. 7a) to a firm feel only. If you have not already done so, insert the Super Plssl 26mm eyepiece into the diagonal prism. Unlock the R.A. (9, Fig. 1) and Dec (7, Fig. 1) locks so that the telescope moves freely on both axes. Point the telescope at some well-defined and stationary land object at least 200 yards distant, such as the top of a telephone pole or street sign. Center the object in the telescope eyepiece. Re-tighten the R.A. and Dec locks. Look through the viewfinder eyepiece (Fig. 7b) and loosen or tighten, as appropriate, one or more of the viewfinder alignment screws (Fig. 7b) until the viewfinder crosshairs are precisely centered on the object you previously centered in the telescope eyepiece. Check this alignment on a celestial object, such as the Moon or a bright star, and make any necessary refinements, using the method outlined in steps 3 and 4.
Mounting Slot Alignment Screws

2. 3. 4.

Thumbscrews Viewfinder Eyepiece
Fig. 7a: Viewfinder Assembly.
Fig. 7b: Viewfinder Assembly.

OBSERVING

IMPORTANT NOTE: Objects appear upside-down and reversed left-for-right when observed in the eyepiece when inserted directly into the (straight-through) eyepiece holder with the diagonal prism in place, images will be right-side-up, but reversed left-for-right. This image inversion is of no consequence when observing astronomical objects and, in fact, all astronomical telescopes yield inverted images. During terrestrial observing, where a fully-correctly-oriented image (right-side-up and correct left-forright) is desirable, an optional #Erecting Prism is available. See OPTIONAL ACCESSORIES, page 41.

Important Tip: It is recommended that you train you telescopes drive the first time you align your telescope. Training the drive improves your telescopes pointing precision. For more information about pointing your telescope, see page 53 for more information.
NOTE: AutoStar requests the Zip Code or the Country/State, City, and Telescope Model information only the first time AutoStar is activated. If you wish to change this information, use the "Site" and "Telescope Model" options in the Setup menu. See page 30 for more information.
Observe a Star using the Automatic Tracking Feature
In this example, the AutoStar Arrow keys are used to find a star, and then AutoStar's tracking capability automatically keeps the star centered in your telescope's eyepiece. 1. 2. 3. Make sure that the Dec and R.A. locks (6 and 9, Fig. 1) are secured as described above. Verify that AutoStar is properly connected to your telescope. See HOW TO ASSEMBLE YOUR TELESCOPE, page 13. Flip the telescope power switch to the ON position. The AutoStar screen is activated and a copyright message displays briefly, followed by a short beep. Then AutoStar takes a few moments to start up the system. 4. 5. 6. 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. Press ENTER (2, Fig. 2) repeatedly until "Setup: Align" displays. Press the Scroll Down key repeatedly until "Setup: Targets" displays. Press ENTER (2, Fig. 2). "Targets: Terrestrial" displays. Press one of the Scroll keys once (7, Fig. 2). "Targets: Astronomical" now displays. Use the Arrow keys (5, Fig. 2) to locate a bright star in the night sky. Use SmartFinder (15, Fig. 1) and /or the viewfinder (1, Fig. 20) to help line up on the star. You may choose any unobstructed, bright star for the purposes of this example. Use AutoStar's Arrow keys to center the star in the eyepiece. Once the star is centered, press ENTER to select "Astronomical." The telescope's tracking motors then engage. It may take the tracking motors several seconds to begin tracking. When they do, it may be necessary to once again center the star in the eyepiece. The tracking motors will then keep the star you have chosen in the center of the eyepiece. Press and hold the ENTER key for a few seconds and then release to stop tracking. You may repeat the procedure to locate another star or object using the Arrow keys. Then press ENTER to re-engage the tracking motors.

IMPORTANT NOTE: While performing the automatic tracking procedure, only use the Arrow keys to move the telescope. Once the telescope has been set in the Alt/Az home position, do not loosen the telescope locks (6 and 9, Fig. 1), or move the base manually, or alignment will be lost.
IMPORTANT NOTE: The "Telescope: Mount" option of the Setup menu is set to "Alt/Az" as the default alignment by the factory.The example presented in this section assumes that you are performing an alignment procedure for the first time with your telescope and therefore, the "Telescope: Mount" option does not need to be selected. For information on equatorial (Polar) alignment, see APPENDIX A, page 46.

Automatic Alignment

After initializing, AutoStar will automatically align your telescope for you. AutoStar is in the alt/az mode (see the margin Note to the left) by default the first time you power it on, so you do not need to select this mode. If you wish to align your telescope in the equatorial (polar) mode, see EQUATORIAL ALIGNMENT, page 46. During automatic alignment, AutoStar automatically detects the level position and the tilt of your telescope, and also determines North (note that the telescope may not be pointing North while it does so). After determining North, AutoStar picks two stars from its database. AutoStar moves the telescope to the 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. The following explains in detail how to perform the alt/az automatic alignment procedure. How to perform the Automatic Alignment procedure 1. No Home Position: AutoStar displays a message that prompts users of some telescope models to set their telescopes in the home position. However, the LX-90 has no home position, so you may start alignment with your telescope in any position you wish. Level, Tilt and Find North: Next your telescope begins to move. AutoStar moves your telescope so that it can calculate the level position and tilt of your telescope, and also calculate the location of True North. While it is performing these functions, the following messages will appear on AutoStars display: Calc Level, Calc North and Calc Tilt.
Note: During this step in the procedure, the telescope may not become level or actually point to North. AutoStar is merely moving the telescope about so that it can calculate these positions. 3. Star Alignment: Next, AutoStar continues to move the telescope (you dont need to press any buttons) in order to choose two stars for alignment. AutoStar will display a name of a star and the word Slewing as it moves to the first star. It will then prompt you to center the star.
However, when the telescope slews to the first star, it may not appear in the field of view in the eyepiece. Use the SmartFinder (17, Fig. 1) and /or the viewfinder (1, Fig. 20) to locate the star. The alignment star will be easy to recognizeit will be the brightest star in the area of the sky where the telescope is pointing. Look through the SmartFinder or the viewfinder and use the Arrow keys to move the telescope until the star is visible. Then look through the eyepiece and center the star using the Arrow keys. Press ENTER. Repeat the procedure for the second alignment star. When the procedure is performed correctly, "Alignment Successful" displays. If AutoStar does not display this message, perform this procedure again. NOTE: The alignment stars may change from night to night. All that is required is for the observer to center the selected stars in the eyepiece when prompted.

Select: To select a Landmark already in the database (see "Add" below), choose the "Select" option and scroll through the list. Press ENTER to select a Landmark, then press GO TO and the telescope slews to the object. Add: To add a Landmark, choose the "Add" option. Enter a name for the Landmark. Locate and center the Landmark in the eyepiece, then press ENTER.
Identify is an exciting feature for an observer who wants to scan the night sky and start exploring. After the telescope has been properly aligned, use the AutoStar Arrow keys to move about in the sky. Then follow this procedure: IMPORTANT NOTE: Only use the Arrow keys to move the telescope during the Identify procedure. Do not loosen the telescope locks or move the base or alignment is lost. 1. When a desired object is visible in the eyepiece, keep pressing MODE until the Select Item: Object menu is displayed. Press ENTER to select this menu. 2. Scroll through the Object menu options until the Object: Identify screen appears. 3. Press ENTER. AutoStar searches the database for the identity of the object being observed. 4. If the telescope is not directly on an AutoStar database object, the nearest database object is located and displayed on the screen. Press GO TO and the telescope slews to that object. Browse allows you to search the database for objects with certain parameters, much like a search engine. "Edit Parameters" lets you set various parameters for the search, such as: Object Type, Minimum Elevation, Largest, etc. Once you have set the parameters of the search, select "Start Search" and press ENTER. AutoStar will display the results of the search. See page 38 for more information.
Use the Event menu to look up dates of various astronomical events, such as sunrises and sunsets, eclipses, moon phases, meteor showers, equinoxes and solstices..and not just for the current date. Set any date, past or future, when initializing AutoStar and you can check the time for other events.

Event Menu

The Event menu provides access to dates and times of astronomical events. The Event database includes: Sunrise and Sunset calculates the time that the Sun rises or sets on the current date. Find rise and set times for other dates by entering a new date into the Setup: Date menu. See "DATE," page 27. Moonrise and Moonset calculates the time that the Moon rises or sets on the current date. Find rise and set times for other dates by entering a new date into the Setup: Date menu. See "DATE," page 27. Moon Phases displays the date and time of the next Full, New, 1st Quarter, and 3rd Quarter Moon. Meteor Showers provides information on upcoming meteor showers, such as the Perseids, the Leonids, etc. Also lists the dates of the showers and when they reach maximum. NOTE: Meteors are fast moving objects that cover large areas of the sky and are usually best observed with the naked eye. Solar Eclipse lists upcoming Solar Eclipses, including the date and type (total, annular, or partial) of eclipse, and the location and time of the first and last contacts of the Moon's shadow. Use the Scroll Up and Down keys to display the available data. Remember, never use a telescope to look at the Sun! See WARNING! to the left. Lunar Eclipse lists upcoming Lunar Eclipses, including the date and type (total, partial, penumbral) of eclipse. Use the Scroll Up and Down keys to display the available data. Min. (Minimum) of Algol is the minimum brightness of the dramatic eclipsing binary star system, Algol. It is relatively close at a distance of 100 light years. Every 2.8 days during a 10hour period, Algol undergoes a major change in apparent magnitude as one of the two stars passes behind the other. The combined magnitude of the two stars thus dips from +2.1 to a minimum of +3.4 halfway through the eclipse as the second star is hidden. AutoStar calculates minimum magnitude time at mid-eclipse. Autumn and Vernal Equinox calculates the time and date of the fall or spring equinox of the current year. Winter and Summer Solstice calculates the time and date of the winter or summer solstice of the current year.

Use the Glossary menu to look up definitions of astronomical terms and get a description of AutoStar features.

Glossary Menu

The Glossary menu provides an alphabetical listing of definitions and descriptions for common astronomical terms and AutoStar functions. Access directly through the Glossary menu or through hypertext words embedded in AutoStar. A hypertext word is any word in [brackets], usually found when using the AutoStar Help function or when reading a scrolling message such as a description of a planet or star. Press ENTER whenever a hypertext word is on screen and AutoStar goes to the glossary entry for that word. To access directly from the Glossary menu, use the Scroll keys to scroll through the alphabet. Press ENTER on the desired letter. Scroll to the desired entry and then press ENTER to read the description.

Utilities Menu

Use the Utilities menu to perform many of AutoStars useful features, such as setting an alarm, adjust the display contrast, calculate the best eyepiece for viewing an object, set up your own landmark survey, and so forth.
The Utilities menu provides access to several extra features within AutoStar, including a countdown timer and an alarm. The Utilities functions include: Timer selects a countdown timer. This feature is useful for functions such as astrophotography and tracking satellites. See OBSERVING SATELLITES, page 32. To use the Timer, press ENTER, then choose Set or Start/Stop."
Set: Enter the time to be counted down, in hours, minutes, and seconds, then press ENTER. Start/Stop: Activates the timer set previously. Use the Scroll keys to toggle between ON and OFF. When ON is displayed, press ENTER to activate the timer. When the timer runs out, four beeps sound and the timer is deactivated.
Alarm selects a time for an alarm signal as a reminder. To use the Alarm, press ENTER, then choose "Set" or "Start/Stop."
Set: Enter the time of day for the alarm to sound, in hours, minutes, and seconds, then press ENTER. Start/Stop: Activates the alarm set previously. Use the Scroll keys to toggle between ON and OFF. When ON is displayed, press ENTER to activate the alarm. When the alarm time arrives, AutoStar beeps. Press ENTER to deactivate the alarm.
Eyepiece Calc calculates information about an eyepiece for the specific telescope to which AutoStar is connected.

Targets switches between Astronomical targets and Terrestrial targets. If "Astronomical" is selected, the telescope tracking motor is activated and any object you observe will remain centered in the eyepiece. If "Terrestrial" is selected, the tracking motor is turned off. To learn how to track an object automatically, see page 18. Site provides access to several options including:
Select: Displays the currently selected observing site. Use the Scroll keys to cycle through all available sites (see "Add" below). Press ENTER when the site you wish to select displays. Use this option when you move to a different geographic location. Add: Allows you to add new observing sites to the database (up to six sites may be stored). Scroll through the list of Countries/States. Press ENTER when the site you wish to add displays. Then choose the desired city in the same manner. Delete: Deletes a stored site from the database. Edit: Edits a selected site, including: the name, latitude, longitude, and time zone. Time Zone refers to the Greenwich Mean Time (GMT) time zone shift. Users West of Greenwich, England use - hours, East of Greenwich use + hours. For the United States, look up the time zone shift in table at left.
Time Zone Atlantic Eastern Central Mountain Pacific Hawaii
Shift -4 Hours -5 Hours -6 Hours -7 Hours -8 Hours -10 Hours
Table 1: Time Zone Shift.
NOTE: AutoStar compensates for daylight savings time, if selected. See SETUP MENU: DAYLIGHT SAVING, page 27. Owner Info accesses the owner information menu, including:
Name: Users may enter both their first and last names using the Up and Down Arrow keys to cycle through the alphabet. Use the Right and Left Arrow keys to move through the text. Press ENTER when the entry is complete. Address: Use the Up and Down Arrow keys to enter your street address, city, state, and zip code. Press ENTER when the entry is complete.
Download transfers information from another AutoStar during cloning (see below). During the operation, the warning Downloading Do Not Turn Off appears. NOTE: The Download function requires the optional #505 Astrofinder Software and Cable Connector Kit. See the instruction sheet included with the kit for more information on how to download. Also see OPTIONAL ACCESSORIES, page 41. Clone uploads information from one AutoStar handbox to another. Three options are available:

3. 4. 5.

AutoStar then prompts you to enter the magnitude of the object. This step is also optional. Use the Number keys to enter this information, if so desired, and press ENTER to go to the next display. "User Object: Add" displays again.
To GO TO a user-entered object: In this procedure, you will choose an object from the User Object list and GO TO the object. 1. 2. 3. 4. With "User Object: Add" displayed, press the Scroll Up key once. "User Object: Select" displays. Press ENTER. Use the Scroll keys (if necessary) to scroll to the desired object. Press ENTER. The name of the object and the Right Ascension and Declination coordinates display. Press GO TO and the telescope slews to the object.

Observing Satellites

In this procedure, you will prepare your telescope to observe a satellite pass. 1. 2. 3. 4. 5. Navigate to the "Object: Satellite" menu option and press ENTER. Use the Scroll keys to scroll through the list of satellites. Select a satellite from list and press ENTER. "Calculating." and then "Tracking." displays. If the satellite is going to make a pass, "Located" displays. Use the Scroll keys to display data about the pass: aosacquisition of signal and losloss of signal. If you subtract the aos from the los, you can calculate how long the satellite will be visible. Location information also displays. "Alarm" displays after the location information. Press ENTER and AutoStar automatically sets the alarm to sound a minute before the satellite's scheduled appearance. You may return to regular observations until the alarm goes off. When the alarm goes off, return to the Satellite menu and press a Scroll key until the desired satellite is on the top line of the display. Press GO TO. AutoStar slews the telescope to where the satellite should appear. The motor drive stops and a countdown is displayed. NOTE: If the scheduled appearance position of the satellite is obstructed (i.e., by a building, tree, or hill), press ENTER and AutoStar starts to move the telescope along the expected satellite track. When the track clears the obstruction, press ENTER again to pause the telescope, then continue with this procedure. 9. With about 20 seconds left on the countdown timer, start watching through the telescope SmartFinder (1, Fig. 17) for the satellite to enter the field of view.

Description String: Description of an object. Must be surrounded by quotation marks. If the description is longer than one line, each line must end with a quotation mark and a hard return. Begin the next description line with a quotation mark. If quotation marks are to be displayed in the on-screen description, use two quote marks at the beginning and end of the desired phrase. For example: "The Orion Nebula is considered " "awesome"" by many who view it."
Writing a Tour Using the list of commands listed above, a custom tour can be created. Placing the word AUTO SELECT before any of the command lines activates Automatic Mode and, when selected, AutoStar automatically searches and finds the designated object. The following is a list of command lines, complete with keywords and necessary strings: TITLE Title must be the first keyword in your tour after any comment lines and must be 15 characters or less. AutoStar displays this title when "Guided Tour" is selected from the menus. For example: TITLE "A Star's Life" TEXT "title string" "description string" This command allows you to display a text title and description. USER ra dec "title string" "description string" This command line allows you to access a specific object with your own description. Enter USER, then the RA and DEC of a desired object, and its title and description. Use the format described in the Command Line section. The following commands specify objects that are already in the AutoStar database. If these commands follow the command AUTO SELECT, the object's title displays on line 1 and its description scrolls across line 2. Do not add a description string after the following command lines; these commands access objects with existing description in the AutoStar database. NGC xxxx Enter NGC followed by the desired New General Catalog number and AutoStar provides the user with a description of the object from its database. For example: NGC 4256 IC xxxx Enter IC followed by the desired Index Catalog number and AutoStar provides the user with a description of the object from its database. For example: IC 1217 SAO xxxxxx Enter SAO followed by the desired SAO number and AutoStar provides the user with a description of the object from its database. For example: SAO 30200 Messier xxx Enter MESSIER followed by the desired Messier number and AutoStar provides the user with a description of the object from its database. For example: M 101 CALDWELL xxx Enter CALDWELL followed by the Caldwell number and AutoStar provides the user with a description of the object from its database. For example: CALDWELL 17 PLANET "name" Enter PLANET and then the name of the desired planet in quotes. AutoStar provides the user with a description of the selected planet from its database. For example: PLANET "Pluto" MOON This command accesses information about the Moon from the AutoStar database. SATELLITE "name" Enter SATELLITE and then the name of the desired satellite in quotes. AutoStar displays information about the satellite from its database. For example: SATELLITE: "Intl Space Stn"

Collimation

The optical collimation (alignment) of any astronomical telescope used for serious purposes is important, but in the case of the Schmidt-Cassegrain design of the 8" LX90, such collimation is absolutely essential for good performance. Take special care to read and understand this section well so that your LX90 will give you the best optical performance. As part of final optical testing, every Meade Schmidt-Cassegrain is precisely collimated at the Meade factory before shipment. However, vibrations in shipping can cause the optical system to become misaligned. Re-aligning the optics is, however, a straightforward process. To check the collimation of your LX90, center a bright star that is overhead, or use a hot spot of reflected Sunlight from a chrome car bumper, with the supplied 26mm eyepiece. Allow the telescope to adjust to the temperature of your observation site before proceeding; temperature differences between the optics and the outside air can cause distortion in the images. With the star or hot spot centered, de-focus the image. You will notice that the out of focus star image looks like a ring of light surrounding a dark central spot; the dark central spot is in fact the shadow of the secondary mirror. Turn the focus knob until the
Fig. 25: Defocused star images.
ring of light fills about 10% of the eyepiece field-diameter. If the dark central spot is offset in (i.e., not concentric with) the ring of light, your telescopes optical system is misaligned and requires collimation. Follow these steps for collimation of the optical system: a. The only adjustments possible, or necessary, on the LX90 are from the three screws (Fig. 25) located at the edge of the outer surface of the secondary mirror housing. CAUTION: Do not force the three collimation screws past their normal travel and do not loosen them more than two full turns in a counterclockwise direction or the secondary mirror may come loose from its support. You will find that the adjustments are very sensitive, usually requiring only one-half turn or less to produce the desired result. b. While looking at the defocused star image, notice which direction the darker shadow is offset in the ring of light or notice which part of the ring is the thinnest (1, Fig. 25). Place your index finger in front of the telescope so that it touches one of the collimation set screws. You will see the shadow of your finger in the ring of light. Move your finger around the edge of the black plastic secondary mirror support until you see the shadow of the finger crossing the thinnest part of the ring of light. At this point, look at the front of the telescope where your finger is aiming. It will either be pointing directly at a set screw, or it will be between two set screws aiming at the set screw on the far side of the black plastic secondary mirror support. This is the set screw that you will adjust. Using the Arrow keys at the slowest slew speed, move the defocused image to the edge of the eyepiece field of view (2, Fig. 25), in the same direction as the darker shadow is offset in the ring of light. Turn the set screw that you found with the pointing exercise while looking in the eyepiece. You will notice that the star image will move across the field. If while turning the defocused star image flies out of the eyepiece field, then you are turning the screw the wrong way. Turn the opposite direction and bring the image back to the center of the field. If the screw you are turning becomes very loose, tighten the other two screws by even amounts. If the screw you are turning gets too tight, unthread the other two by even amounts. When you bring the image to center (3, Fig. 25), carefully examine the evenness of the ring of light (concentricity). If you find that the dark center is still off in the same direction, continue to make the adjustment in the original turning direction. If it is now off in the opposite direction, you have turned too far and you need to turn in the opposite direction. Always double check the image in the center of the field of the eyepiece. You may find after your initial adjustment that the dark center is off in a new direction (e.g., instead of being off side-to-side it is now off in an up-and-down direction). In this case repeat steps b through f to find the new adjustment screw. Now try a higher power eyepiece (e.g., 9mm or less) and repeat the above tests. Any lack of collimation at this point will require only very slight adjustments of the three set screws. You now have good collimation of the optics. As a final check on alignment, examine the star image in focus with the higher power eyepiece as suggested above, under good viewing conditions. The star point should appear as a small central dot (commonly referred to as an Airy disc) with a diffraction ring surrounding it. To give a final precision collimation, make extremely slight adjustments of the three set screws, if necessary, to center the Airy disc in the diffraction ring. You now have the best alignment of the optics possible with this telescope.

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 appears to be scratches, dark or bright spots, or just generally 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.
Gauging the Movement of the Telescope
A common complaint of many first-time telescope owners is that they cannot see the telescope move when the motor drive is engaged. If fact, when the batteries are installed, the power is on and the R.A. lock engaged, the telescope is moving. However, the movement is at the same speed as the hour hand of a 24-hour clock; as such, the movement is difficult to discern visually. To check the movement of your telescope, look at an astronomical object through the telescopes eyepiece with the telescope polar aligned and with the motor drive on. If the object remains stationary in the field of view, your telescope is operating properly. If not, check to ensure that you have engaged the R.A. lock and that the power switch on the control panel is on. Also check if "Astronomical" is selected in the "Targets" option of the setup menu.

Fig. 26: R.A. Lock.

Meade Customer Service
If you have a question concerning your LX90 telescope, call the Meade Instruments Customer Service Department at (949) 451-1450. Customer Service hours are 7:00 AM to 6:00 PM, Pacific Time, Monday through Friday. In the unlikely event that the LX90 requires factory servicing or repairs, write or call the Meade Customer Service Department first, before returning the telescope to the factory, giving full particulars as to the nature of the problem, as well as your name, address and daytime telephone number. The great majority of servicing issues can be resolved by telephone, avoiding return of the telescope to the factory.

Fig. 27: Dec Lock.

LX90 TIPS Look into the Future
The Date option in the Setup menu is much more than just an entry of today's date; with it you can look far into the future or learn about past events. AutoStar can calculate the date and times of future events and, except for eclipses, past events as well (based on the current calendar system). E.g., a Sunrise on March 6, 2043 A.D. or the Vernal Equinox in 1776 A.D. To use this feature, enter the desired date in the Setup menu or select an option in the Event menu. AutoStar, using the Event menu, can calculate dates and times for Sunrises, Sunsets, Moonrises, Moonsets, Moonphases, Solar and Lunar Eclipses (for the next 100 years), meteor showers, equinoxes and solstices and the minimums of Algol. One very practical use of the Event menu is to check the Sunset option to determine when you can begin your astronomical observing session.

Precise Polar Alignment

It should be emphasized that while doing casual observing, precise alignment of the telescopes polar axis to the celestial pole is not necessary. Dont allow a time-consuming effort at lining up with the pole to interfere with your basic enjoyment of the telescope. For long-exposure photography, however, the ground rules are quite different, and precise polar alignment is not only advisable, but almost essential. Even though the LX90 telescopes offers a sophisticated drive system, the fewer tracking corrections required during the course of a long-exposure photograph, the better. (Long-exposure means any photograph of a celestial object that last for 10 minutes or longer). In particular, the number of Declination corrections required is a direct function of the precision of polar alignment. Precise polar alignment requires the use of a crosshair eyepiece. The Meade Illuminated Reticle Eyepiece (see OPTIONAL ACCESSORIES, page 41) is well-suited in this application, but it is also preferable to increase the effective magnification through the use of a 2X or 3X Barlow lens as well. Follow this procedure (particularly if the pole star is not visible), sometimes better known as the Drift method:
1. Obtain a rough polar alignment as described earlier. Place the illuminated reticle eyepiece (or eyepiece/Barlow combination) into the eyepiece holder of the telescope. 2. Point the telescope, with the motor drive running, at a moderately bright star near where the meridian (the North-South line passing through your local zenith) and the celestial equator intersect. For best results, the star should be located within 30 minutes in R.A. of the meridian and within 5 of the celestial equator (see CELESTIAL COORDINATES, page 47). Pointing the telescope at a star that is straight up, with the Declination set to 0, will point the telescope in the right direction. 3. Note the extent of the stars drift in Declination (disregard drift in Right Ascension): a. If the star drifts South (or down), the telescopes polar axis is pointing too far East. b. If the star drifts North (or up), the telescopes polar axis is pointing too far West. 4. Move the wedge in azimuth (horizontally) to effect the appropriate change in polar alignment. Reposition the telescopes East-West polar axis orientation until there is no further North-South drift by the star. Track the star for a period of time to be certain that its Declination drift has ceased. 5. Next, point the telescope at another moderately bright star near the Eastern horizon, but still near the celestial equator. For best results, the star should be about 20 or 30 above the Eastern horizon and within 5 of the celestial equator. 6. Again note the extent of the stars drift in Declination: a. If the star drifts South, (or down) the telescopes polar axis is pointing too low. b. If the star drifts North, (or up) the telescopes polar axis is pointing too high. 7. Use the altitude adjust control on the wedge to make appropriate changes in altitude, based on your observations above. Again, track the star for a period of time to be certain that Declination drift has ceased. The above procedure results in very accurate polar alignment, and minimizes the need for tracking corrections during astrophotography.

Installation Instructions

LNT SmartFinder Lens

For use with Meade LX-90 Series Telescopes

Introduction

The LX90 telescope is shipped with the LNT module attached. However, the lens for the SmartFinder is shipped unattached so that it is not damaged or scratched during transport. Front of LNT
Assembly 1. The lens for the SmartFinder is shipped with a protective film to protect the lens coating. Do not remove this film until told to do so in the instructions.
Fig. C: Inset tongue into LNT module slot.
You may need to wiggle the lens/tongue a bit to slide the tongue into place. You will hear an audible click when the lens is completely inserted and locked into place. Remove the remainder of the plastic film from the lens, but avoid touching the lens as you do soyou may scratch the lens or leave fingerprints.
Fig. A: Lens with protective film.
First peel back the film from just the tongue of the SmartFinder lens. Tongue
Fig. D: Remove the rest of the protective film.
Fig. B: Peel back film from just the tongue of the lens.
To clean the surface of the lens, use a camel hair brush to gently remove the dust. A high-quality lens cleaning cloth is also acceptable.
If you have a question concerning use of the Meade 2. Insert the tongue into the SmartFinder slot. Angle the tongue towards the front of the LNT module as you slide it into place.
SMARTFINDER, call the Meade Instruments Customer Service
Department at (949) 451-1450. Customer Service hours are 7:00 AM to 6:00 PM, Pacific Time, Monday through Friday.

Part no. 14-0670-02

Ver. 11-04