Meade Instruments Corporation
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Meade LX200 Instruction Manual
7" Maksutov-Cassegrain, and 8", 10", and 12" Schmidt-Cassegrain Telescopes
 G. MODE FUNCTIONS
IMPORTANT NOTICE! Never use a telescope or spotting scope to look at the Sun! Observing the Sun, even for the shortest fraction of a second, will cause irreversible damage to your eye as well as physical damage to the telescope or spotting scope itself.
To view the separate modes within the LX200 system, press the MODE button located between the ENTER and GO TO keys at the top of the hand controller. Simple entry and editing of information in the different modes contained within the system, will customize the operation of your LX200 to perform virtually any of your observing requirements. Better still, all of the critical information such as time, location, alignment type, and many other functions are kept in memory...even with the LX200 turned off!

The type of alignment, the objects that you see, the location that you observe from, the tracking speeds of the drives, all of the clock and timing functions, the position information, and even the brightness level of the backlit Keypad are defined by the information that you give and/ or the commands that you edit, through five different modes of the LX200 computerized hand controller.

Once you have selected the desired mode, you can then select the individual file within the mode by pressing the PREV or NEXT key (up and down arrow key) in the bottom right hand portion of the hand controller, moving the LCD arrow up or down beside the file description. Although you will only be able to see two menu selections at a time in the Keypad Display, you will see more as you continue to press the PREV and NEXT keys.

When the desired file is chosen, press the ENTER key to view the file's menu. To choose an individual menu, again use the PREV or NEXT key to run the LCD arrow up or down the file's menu. To explore a menu selection, again press the ENTER key. In some modes there will be options for a file's menu selection, in others you will only enter data.

At any time that you wish to return to main file heading in a particular mode, just press MODE and it will behave as an exit key.

[ toc ] 1. Mode One: TELESCOPE/ OBJECT LIBRARY

This is the mode that the LX200 will default to after the instrument completes its self-check, when the LX200 is first turned on. The TELESCOPE/OBJECT LIBRARY mode can be thought of as command central. It is here that we can select the way that we want the LX200 to perform mechanically, and where we can explore and select from its extensive library of stored objects.

To explore either the TELESCOPE menu file or the OBJECT LIBRARY menu file, move the LCD arrow to the appropriate selection by using the PREV or the NEXT key and press the ENTER key.

[ toc ] a. TELESCOPE Menu File

Below are the eleven menu selections of the TELESCOPE menu file illustrating the individual menu files and file options.

[ toc ] 1) SITE

The SITE menu option allows you to enter up to four of your favorite viewing locations in longitude and latitude. The entered longitude and latitude is compared by the LX200's computer to your local time, GMT offset, and calendar date to accurately calculate celestial coordinates. Once entered, the information is stored in the telescope's internal memory, you need never to re-enter the same information unless you decide to change it. To enter new site information or to change an old one, refer to section D. Quick Start.

You can choose any one of the four site selections at your convenience, without the bother of entering longitude and latitude every time you use the LX200. Once the site is chosen, exit the SITE menu by pressing the MODE key.

[ toc ] 2) ALIGN

The Align menu selection of the TELESCOPE file demonstrates the unique ability to transform the LX200 into an Altazimuth, celestial tracking telescope, a polar-equatorial celestial tracking telescope, or land spotting scope with electric Altazimuth movements within three options, which are; ALTAZ, POLAR, and LAND.

Assuming that you have already entered correct local time and your site' s latitude and longitude (refer to section D. Quick Start) you are ready to choose a particular type of alignment, by pressing the NEXT or PREV key to run the LCD arrow beside the desired option of ALTAZ, POLAR, or LAND, and then pressing the ENTER key. The display will then give you specific instructions from this point that will literally walk you through the chosen alignment type.

[ toc ] a) ALTAZ

The 2-Star initialization routines provide three options for aligning the LX200 telescope when in the ALTAZ mode. (Note: The 2-Star initialization routines only apply to the ALTAZ alignment mode.

The first and second options require that you have entered the SITE and TIME information, and the third option can be used when the SITE information is not known or has not been entered into the LX200's memory.

[ toc ] a. 1-Star with Known SITE

After selecting the SITE location (1-4), move to the ALIGN menu (see steps 5-9).

When you select the ALTAZ alignment mode, the display will give you two options: 1-Star or 2-Star alignment. If you select the 1-Star alignment (by pressing the "1" key), the alignment routine is exactly the same as the procedure described earlier.

[ toc ] b. 2-Star at Known SITE

To use the 2-Star alignment procedure at a known site, follow these steps:

(1) Select the 2-Star alignment (by pressing the "2" key); the Keypad display will prompt you to level the tripod. This leveling step requires a rough level only and, unlike the 1-Star alignment routine, does not affect the pointing accuracy of the telescope. (See Section d. below for a summary of the differences in telescope operation when selecting each of the three alignment procedures.)

(2) After leveling the base and pressing ENTER, follow the Keypad display prompts to select the first alignment star. Slew to that star using the N, S, E, W keys. (3) Follow the Keypad display prompts to choose and center the the second alignment star. Be sure to use the Keypad to slew to the second star. After pressing the ENTER key in the last step, the Keypad display should show the TELESCOPE / OBJECT LIBRARY screen.

The LX200 calculates the distance between the two stars that you chose in the alignment steps and compares this to the distance that you actually slewed the telescope. This is a check to be sure you centered the correct stars during the alignment steps. Should the LX200 discover a discrepancy, the Keypad will display an "Align Mismatch - Check Stars" message. If you get this message after aligning the telescope, check that you are using the correct stars and align again.



IMPORTANT

Whenever using either of the two 2-Star alignment procedures (at a known SITE or at an UNKNOWN SITE), choosing the proper two stars will determine the pointing accuracy of the telescope. Choose two stars that are not too close together—try to use stars that are at least 90° apart. Do not use Polaris as one of the stars because RA changes very fast at the Pole and minor centering errors can translate to large RA pointing errors. Also, avoid stars near the zenith (straight up) since azimuth changes very fast in this area. Generally speaking, choosing two stars as far apart as possible will yield very accurate pointing.


[ toc ] c. Unknown SITE

To use the LX200 telescope at an unknown location, use the following procedure:

(1) Select site #5 (UNKNOWN) from the SITE menu. (Note: This site cannot be edited like site numbers 1-4 as described on steps 4-10.)

(2) Follow the Keypad display prompts to select and center the two alignment stars.

As described above, the LX200 will check the accuracy of the two stars and give the "Align Mismatch - Check Stars" message if it detects an error.

[ toc ] d. Which Alignment Method To Use?

Each of the three methods described above have advantages and disadvantages. The following table summarizes these properties.

  Pointing Accuracy Determined By: Atmospheric Refracting Correction* Atmospheric Refraction Correction Determined By: When Best Used
1-Star Known SITE Level of Telescope Yes Level of Telescope Best used when the telescope is permanently mounted and accurately leveled.
2-Star: Known SITE 2-Star Alignment Yes Level of Telescope Best used on a transportable telescope with the SITE information available.
2-Star: Unknown SITE 2-Star Alignment No N/A Best used when the SITE information is not available.
*Atmospheric Refraction Correction: Light from a astronomical object is "bent", or refracted, as it passes through the atmosphere. This bending is more pronounced near the horizon because there is more atmosphere for the light to pass through, and it shifts the apparent position of the star. The LX200 calculates this bending and compensates for it when slewing to objects near the horizon.

[ toc ] b) POLAR

POLAR allows you to use the LX200 mounted on its' optional Equatorial Wedge (see Appendix A) for long exposure astrophotography as well as visual work. With the LX200 powered up, the POLAR file option selected, the Field Tripod leveled, the telescope should be adjusted so that the Declination Setting Circle (3, Fig. 3) is set to 90 degrees (see Fig. 4), and to the 00 hour angle (HA) in Right Ascension (in this position, the Viewfinder (Fig. 3) is up-side down, the R.A. Pointer (9, Fig. 3), the 00 line of the R.A. Setting Circle (10, Fig. 3), and the Hour Angle Pointer (16, Fig. 3) match up), you are ready to start. (If you do not start at the 00 H.A. position, the telescope it will point to the ground instead of the sky, when the Keypad display chooses its' second star.) Press the ENTER key and the LX200 will determine and slew to the precise off-set of the pole star in Declination and Right Ascension.

At this point you need only aim the instrument at the pole star (see Appendix B, section 3. Precise Polar Alignment if the pole star is not visible) and center it in the eyepiece field using only the Altitude and Azimuth adjustments on the Equatorial Wedge (see Appendix A). Once done, you again press the ENTER key and the LX200 will choose and slew to a very bright star that is overhead and can usually be seen in the field of view of the viewfinder. At this point, center the bright star using only the Right Ascension and Declination adjustments of the telescope (either manually by loosening the locks only or electrically), then press ENTER. You can now access every every function of the LX200 including the Smart Drive.

[ toc ] c) Refined Polar Alignment

Astrophotographers routinely require polar alignments of the highest accuracy for the finest guiding characteristics. Your initial polar alignment can be refined by using the LX200's electronics by using a slightly different method in POLAR menu option. The routine outlined below should be performed in two or three 15 minute intervals. At each interval the telescope will slew to the area where the pole star should be centered in the optics. You may find that the pole star is somewhat off-center in the eyepiece showing the alignment error that may have been made during your initial setup. Re-center the pole star during each interval exercise using the Equatorial Wedge adjustments only (see Appendix A) in Altitude and Azimuth, then follow the rest of the routine.

Return to the POLAR menu option in the TELESCOPE mode and press the ENTER key.

Ignore the Keypad display instructions to return the telescope to 90 degrees in Declination and 00 HA. Instead, press the GOTO key and the LX200 will slew to the calculated position of where the pole star should be.

Re-center the pole star in the field of view in the eyepiece using only the adjustments on the Equatorial Wedge (see Appendix A) in Altitude and Azimuth.

Press the ENTER key, and the LX200 will once again slew to a bright star overhead. Center this star using the N,S,E, or W keys and press ENTER. Note: Pressing the MODE key at any point in the alignment routine will abort the routine and exit to the top menu.

After each 15 minute interval you will find that the pole star becomes more accurately centered each time. You can repeat the intervals as often as you like to obtain the highest accuracy. An optional illuminated reticle crosshair eyepiece* makes the job of centering the star easy.

There may be situations when it is impossible to see the pole star due to something blocking your line of sight. In such an occasion, just press the ENTER key next to the POLAR option so that it has a check next to it and follow the Precise Polar Alignment instructions in Appendix B to this manual. You will require the use of an illuminated reticle crosshair eyepiece* to complete the task. Once finished, follow the steps in The Permanently Mounted, Polar Aligned LX200 section to access the Object Library.

[ toc ] d) The Permanently Mounted, Polar Aligned LX200

For those who will permanently mount the LX200 in an observatory, or wish to use the already polar aligned telescope for several nights in succession, it is recommended that a high-precision polar alignment be made with one of the methods described above. Once done, however, you need not bother yourself to go through a polar alignment routine on successive nights, provided that you do not move the instrument's Equatorial Wedge or Field Tripod, to access the Object Library and enjoy near perfect tracking.

To bypass the polar alignment sequence, follow the steps outlined below:

1. Return to the POLAR menu option and place a check next to it by pressing the ENTER key.

2. Then directly enter the catalog number of an object that you are familiar with in the sky by pressing the M, STAR, or CNGC key (see Appendix D. for a listing of the 64,359 Object Library) and press the ENTER key again.

3. Manually center the familiar object in the eyepiece of the telescope.

4. Press and hold the ENTER key until the display reads 'Coordinates matched'.

5. You have now synchronized the Object Library and the LX200 will correctly access every other object in the sky.

[ toc ] e) LAND

The LAND menu option transforms the ALTAZ (Altazimuth) mounted LX200 into an electric slewing spotting scope. In this mode, continuous tracking is canceled and all of the celestial pertinent modes and menus are non-functional, showing lower case lettering in the displays and a beep tone if you try to enter one of them.

The LX200 will slew at any one of the four speeds of SLEW, FIND, CNTR, and GUIDE as activated by pressing the appropriately marked keys on the extreme left of the Keypad display. Altazimuth coordinate readings can still be displayed in the coordinates mode (see MODE 2 in this section). Refer to section D. Quick Start in this manual for the LAND menu option, for full operating procedures. You will also find that the addition of the Meade #928 45 Degree Erect Image Prism or the Meade #924 Porro Prism* instead of the standard supplied star diagonal prism, will give the normal right side up and left to right views that you are accustomed to when using a spotting scope.

[ toc ] 3) SMART

The SMART menu file controls the Smart Drive and allows you to train almost all of the periodic error from the Right Ascension drive worm gear (errors induced by tiny gear imperfections that tend to slightly speed up or slow down the drive tracking speed, that occur in a regular 8 minute pattern, or for every rotation of the worm) for greatly enhancing the tracking characteristics or the amount of East and West drift of your LX200. This greatly simplifies guiding during astrophotography. The menu also has provisions for correcting Declination drift. Smart Drive will retain the training given to the R/A drive, even after the telescope is turned off. There is of course a way to erase any training given to it at your command.

The SMART menu has five options. They are; LEARN, UPDATE, ERASE, DEC LEARN, and DEC CORRECT. To use the Smart Drive, the LX200 must be mounted with the optional Equatorial Wedge (see Appendix A), equipped with an illuminated reticle eyepiece*, and used in the POLAR align menu selection. Be sure to train the Smart Drive in the 60.1 Hz Quartz setting that the LX200 will be automatically set at power up. Thereafter, you can adjust this setting in the TIMER/ FREQ mode and still enjoy the periodic error correction.

Once a polar alignment has been completed, your LX200 will point to a bright star overhead that will be near the Celestial Equator. This will be a good star to train the Smart Drive on. You can of course, move to another star just as long as you are near 0 degrees in declination and more or less overhead in Right Ascension. Now is good time to set the brightness and/ or the pulse rate (see section E. The LX200 Keypad) of the illuminated reticle on the guide star and practice guiding for a few minutes.

To actually begin training the Smart Drive, move the LCD arrow to LEARN by using the PREV or NEXT key and press ENTER. There will be numbers that will appear next to the LEARN display, that will begin counting down to zero. The highest number that can appear is 240. The period of the worm is eight minutes and the number represents a sector of the worm wheel which will change to the next lower digit every two seconds. As the Keypad display approaches sector 5, an alarm will alert you that training is about to commence. At this point try to keep the star on the same location of the crosshair during the eight minute training sequence by pressing the N,S,E, and W keys. After eight minutes, the training is over and Smart Drive will play back your drive corrections automatically, dramatically improving the R.A. drive tracking characteristics.

If you wish to further refine the accuracy, move the LCD arrow to UPDATE and press ENTER and follow the same instructions as above. This can be done in UPDATE as many times as you wish. With each training the Smart Drive will average your training sequences.

If you find that you have made a mistake in training (e.g. pushed E instead of W when you should have), you can eliminate the memory by moving the LCD arrow to ERASE and press ENTER.

A star that drifts consistently North or South during guiding, can also be corrected for. Move the LCD arrow to DEC LEARN and press ENTER. Begin making drive corrections immediately by pressing any of the direction (N, S, E, W) keys to keep the star on the crosshair of the guiding eyepiece. It is suggested that you train in DEC LEARN for at least half of your intended exposure time for an astrophoto. The longer that you train, the more accurate the DEC LEARN will be. Once the desired time is finished, press ENTER and the training will cease. The Smart Drive will then determine how many key pushes that you gave in N and S and choose the direction based from which direction received more commands. It then averages the time between key pushes in the chosen direction. In this way, the Smart Drive can correct for Declination drift (should your polar alignment be slightly off), or will allow you to more precisely guide on non-stellar objects, such as comets, asteroids, etc.

To play back your DEC LEARN training, move the LCD arrow to DEC CORRECT and press ENTER. To halt the play back press ENTER again. To erase the DEC LEARN training, either move the LCD arrow back to DEC LEARN and press ENTER twice or turn the LX200 off.

[ toc ] 4) 12/24 HR

The 12/24 HR menu selection of the TELESCOPE file simply toggles between a twelve and twenty-four hour display of local time in the time mode.

To toggle between 12 and 24 hours displays, move the LCD arrow to 12/24HR and press ENTER. To return to the original setting, press ENTER again.

[ toc ] 5) HELP

The HELP menu selection of the TELESCOPE file is an electronic mini-manual that will briefly describe the function of each command key on the LX200 Keypad.

To use this menu, move the LCD arrow with the PREV or NEXT key to HELP and press ENTER. To read the lines of text, use the PREV and NEXT keys. To exit, press MODE.

[ toc ] 6) REVERSE NS

The REVERSE NS menu seletion of the TELESCOPE file reverses the direction of the telescope in North and South movements (e.g. when you press the N key the scope will move South or down instead of North or up). This is especially useful during some guiding applications in imaging and observing.

To use the REVERSE NS menu, move the LCD arrow to REVERSE NS and press ENTER. If you wish to return the direction commands to the original setting, press ENTER again.

[ toc ] 7) REVERSE EW

The REVERSE EW menu selection of the TELESCOPE file reverses the direction of the telescope in East and West movements (e.g. when the W key is pressed, the telescope moves East). This is particularly useful during some guiding applications in imaging and guiding.

To use the REVERSE EW menu, move the LCD arrow to REVERSE EW and press ENTER. If you wish to return the direction commands to the original setting, press ENTER again.

[ toc ] 8) BALANCE

When adding optional equipment to the LX200, like a heavy camera or Dewshield, it is often necessary to rebalance the telescope using the Meade #1401 (for 8" LX200's), #1402 (for 10" LX200's) , or #1403 (for 12" LX200's) Tube Balance Weight Systems.

Selecting option #8 from the TELESCOPE menu moves the LX200 telescope rapidly up and down in Declination. This provides an easy way to determine when the telescope is balanced in the Declination axis. (Remember, loosening the Dec. lock to check the balance will cause the LX200 to lose alignment.)

When the telescope is out of balance, the LX200 will draw more current when slewing in the "heavy" direction. Also, the Declination motor will sound different.

After selecting option #8, watch the Ammeter and listen to the Declination motor to determine when the LX200 is balanced.

[ toc ] 9) HP (High-Precision Pointing)

The High-Precision Pointing (HP) feature of Meade LX200 Schmidt-Cassegrain telescopes allows for very precise pointing of the telescope. By incorporating the unique LX200 SYNC command, 0.3 arc-sec resolution encoders, and high-speed DC servo motors, observers can now place objects in the telescope's field of view with 1 arc-minute or better pointing accuracy, making critical image placement applications, such as CCD imaging, possible.

[ toc ] a) LX200 Pointing Accuracy

Normal telescope pointing accuracy is better than 5 arc-minutes when doing a casual alignment, which is more than accurate enough for many observing applications. (A "casual" alignment is one that uses the UNKNOWN SITE or one that is done without the use of a reticle eyepiece to EXACTLY center the alignment stars.) This type of alignment will put objects into the field of view of most eyepieces and is more than adequate for almost any visual observing application.

A "critical" alignment will improve the pointing accuracy of the telescope. This type of alignment requires accurate SITE information, time, date, proper selection of the two alignment stars, and a reticle eyepiece to exactly center the alignment stars. These steps generally require only a few extra seconds to accomplish, and improve the telescope's positioning by a substantial amount. Using the "critical" alignment will provide telescope positioning suitable for all but the most demanding pointing applications - including CCD imaging with larger chip cameras, like the Meade Pictor 416 and Pictor 1616 CCD cameras.

The HP feature increases the pointing accuracy of the LX200 to 1 arc-minute or better and also requires the "critical" alignment procedure described above. This alignment procedure will yield the best pointing accuracy possible, placing images of objects onto the active area of the even the smallest CCD cameras available.

It should be stressed that for most applications, using the HP feature is NOT required to get maximum enjoyment out of the telescope. For an evening of simple visual observations, the "casual" alignment is all that is required. Don't let the pointing precision of the telescope become more important than the fun of observing the night sky!

[ toc ] b) Using HP


The High-Precision Pointing mode requires the "critical" alignment, described above, to maximize the telescope's pointing ability. The LX200 default condition is with HP disabled. To activate the HP mode, select the "high-precision" option from the TELESCOPE menu (option #9). When selected, "HIGH-PRECISION" will change to all upper case letters.

When HP is active, the LX200 automatically does several things whenever a GOTO is initiated.

1. HP will search the alignment star database and find the three closest stars to the object (or position) entered. This process takes about 10 seconds and the keypad displays:

"HIGH-PRECISION"

" Searching ...... "

2. The telescope will slew to the nearest alignment star. These are all bright (brighter than 3rd magnitude) stars and far enough apart to insure that there will only be one in the field of view.

3. The keypad display will display:

"Center STAR XXXX"

" then press GOTO."

Using a reticle eyepiece, center the star in the field of view. (Or center the star on the CCD chip if using a CCD camera.) Press GOTO when the star is centered.

Note: If this star is not in the field of view or if it is obstructed by a land object, the other two stars are available. Use the PREV and NEXT keys to cycle through the three closest stars.

4. The telescope will slew to the selected object or position.

[ toc ] 10) SLEW RATE

Option #10 in the TELESCOPE menu is for changing the slew rate of the LX200 telescope. Slowing down the slew rate will result in less noise as the telescope moves and will also use a little less power. To change the slew rate, follow these steps:

1. Press the MODE key on the Keypad until the TELESCOPE / OBJECT LIBRARY menu appears on the display. The cursor should be next to the TELESCOPE option - if not, then press the PREV key to move the cursor up one space.

2. Press ENTER to select the TELESCOPE functions.

3. Press the PREV or NEXT keys to move the cursor to option #10: SLEW RATE. On the right hand part of the display, the number 8 is displayed (6 is displayed on Version 4.34 for 12" LX200 telescopes). This represents the current slew rate in degrees per second.

4. Press the ENTER key to change the slew rate. Each successive ENTER key press increments the slew rate by 1 degree per second.

5. After setting the desired rate, press the MODE key to return to the TELESCOPE / OBJECT LIBRARY menu.

Note: The slew rate is NOT stored in permanent memory and needs to be reset each time the telescope is powered up. The default slew rate is 8 degrees per second on Ver. 3.30 and 6 degrees per second on Ver. 4.34.

[ toc ] 11) DEC. BACKLASH COMPENSATION

When taking long exposure astrophotographs, it is necessary to "guide" the photograph to make sure the telescope is tracking perfectly, otherwise stars will appear as ovals instead of pinpoints. This is done by setting the LX200 Keypad to the GUIDE speed, monitoring the star location (e.g. with an off-axis guider), and making small corrections to the telescope position by using the N, S, E, and W keys.

When making these corrections, the R.A. motor will speed up or slow down (by pressing the "E" and "W" keys). The Declination motor, however, when activated (by pressing the "N" and "S" keys) will actually stop and reverse direction. Because of backlash in the Declination motor gearbox, there will be a few seconds delay before the telescope begins to move when reversing direction.

The Dec. backlash feature compensates for the Dec. motor gearbox backlash and provides instant telescope movement when the motor direction is reversed. (Note: this feature is only available in the POLAR mode.)To program the Dec. backlash, use the following procedure:

1. Move to option #11 from the TELESCOPE menu. The Keypad display will show:

"­p;>11) BACKLASH 00."

The "00" in the display shows the number of arc-seconds of backlash the LX200 is set to compensate for (the default setting is 0 arc-seconds).

2. While observing a star at high power, time the Declination movement delay when reversing the motor directions (by pressing the "N" and "S" keys). Typical values are 2 to 4 seconds.

3. The GUIDE speed for the Declination motor is 15 arc-seconds per second. Therefore, multiply the number of seconds delay by 15.

4. Press and hold the ENTER key for 1 second. The Keypad will beep and a blinking cursor will appear on the Keypad display. Enter the number determined in step 3, above. Press ENTER when the number is entered.

5. Check the time delay as described in Step 2, above. If there is still a time delay, then increase the compensation number. If there is a slight jump when reversing direction, then the number is too large.

When the compensation number is correct, the LX200 telescope will move almost instantly when reversing the direction in Declination. This number is stored in permanent memory and should never need to be set again.

[ toc ] b. OBJECT LIBRARY Menu File

The OBJECT LIBRARY menu file is the other half of the TELESCOPE/OBJECT LIBRARY mode. With it you can become a tourist of the sky, or conduct research surveys of the 64,359 objects. The LX200 Object Library is accessible in the most results-getting, user friendly system ever designed for observers and astrophotographers.

The position epoch of these objects is for real time, updated every time you turn on your LX200. Even the planet's positions have their orbits calculated! This not only qualifies the LX200 as the most accurate integrated object library available, it will never require updated software for precession of the stars or planetary orbital changes.

There are three primary ways to use the Object Library. You can directly access the library by using the M, STAR, or CNGC keys (see section E. The LX200 Keypad) and entering a specific catalog number, the START FIND option can be used to logically find objects in organized strips of the sky that can be custom tailored to only show the objects you wish to see with a selection of object types, size brightness, etc., or you can scan the sky and have the Object Library tell you what is in the field of view in the eyepiece by using the FIELD option. Below is a description of the four OBJECT LIBRARY menu files and file options:

To access the OBJECT LIBRARY menu file, move the LCD arrow to the OBJECT LIBRARY display by pressing the PREV or NEXT key while in the TELESCOPE/ OBJECT LIBRARY mode and press the ENTER key. Now you can access the four menu selections within the OBJECT LIBRARY by moving the LCD arrow to the desired menu selection by using the PREV or NEXT keys and doing the following steps.

[ toc ] 1) OBJECT INFO

Press the ENTER key to read the type, brightness, size, and quality. Press ENTER again to read the coordinates. Press ENTER once more to determine how far off the telescope is pointing from the entered object (this is displayed in LCD bars, each bar is ten degrees, or if it is on the object, no bars). This same information can also be accessed at any time by pressing the ENTER key for any object entered by the M, STAR, or CNGC keys. Press MODE to exit to the main menu file.

[ toc ] 2) START FIND

The START FIND option resources the CNGC objects within the Object Library and begins a logical search starting wherever the telescope is positioned when activated. To cover the entire visible sky it will make 31 strip divisions about 12 degrees wide, moving from West to East, from the North Pole to the South Pole, then South to North. Once it has found all of the CNGC objects it will repeat its sequence until new objects are visible.

Press the ENTER key and the hand control will display the first object in its finding sequence. This first object is selected by the LX200, based off of where the instrument is pointing in the sky when you entered START FIND. To point your LX200 to the object displayed, press the GO TO key and it will slew to the object.

While in the START FIND option, you can either choose the next object in line or skip it as you wish. In order to find the next object in sequence, press the NEXT key, and the display will read the new CNGC object. If you do not wish to view this object, you can skip it by pressing NEXT again. If you wish to return to a previously viewed object, press the PREV key until the desired catalog number is displayed and press the GO TO key. If you have set some limitations in the PARAMETERS option, it will only find those objects within your chosen confines.

If you find that the object is not well centered in the eyepiece after executing a GO TO (due to poor leveling, improper time input, or errors in site location), center the object; then press and hold the ENTER key until the display reads "Coordinates Matched." This feature in essence synchronizes the LX200 for an area of the sky, so that the next object (if the leveling, time input, or site location information is not corrected) will be better centered, provided it is not too far away from the object that you matched coordinates to.

To exit the START FIND menu selection (and cease its operation) to the main menu, press the MODE key.

[ toc ] 3) FIELD

Press the ENTER key to identify objects in the field of view of the telescope. The LX200 will display the object centered in the eyepiece field, and how many other NGC objects are in the field at the same time (defined by the RADIUS parameter setting) as shown in Display 25:

Press the ENTER button to reveal information about the object as shown in Display 26:

Display 26 is interpreted; COMPUTERIZED NEW GENERAL CATALOG #4438, VERY GOOD, GALAXY, MAGNITUDE 10.1, SIZE (in arc minutes) 9.3'. Press ENTER again to read the coordinate location of the object (notice the * legend next to RA coordinate number, it indicates the catalog coordinates of the object, not necessarily where the telescope is pointing) as shown in Display 27:

Press ENTER once more to see physically how far your telescope will have to move to acquire the object entered. The display will show LED bars, each bar represents ten degrees of movement as shown in Display 28:

If you are centered on the object already, such as if you are in the FIELD menu selection, or if you have already made a GO TO command in one of the other methods for finding an object, the above display will be blank.

To review any of the data of an object, continue to press the ENTER button until the desired field appears. You can use the above commands at any time that you have an object entered in the Keypad, while directly entering in specific objects by pressing the M, STAR, or CNGC keys, in the START FIND menu selection, the OBJECT INFORMATION menu selection, or the FIELD menu selection.

[ toc ] 4) PARAMETERS

It is here that you can edit the Press ENTER to find eight options which can be reviewed by scrolling through this menu selection by using the PREV or NEXT key. To edit one of the options, move the arrow to the desired option and press and hold the ENTER key until a double beep is heard and a blinking cursor appears (except in the BETTER option) Where numerical values are to be input, simply type them in from the Keypad. If you make a mistake, you can move the cursor backward using the W key, then re-enter the data. To exit to the main option menu, press the ENTER key once again. A description of the eight options and how to set them is below:

[ toc ] a) TYPE GPDCO

This menu file option allows you to select the type of CNGC objects that you wish to locate. The symbols GPDCO represent:

Table 5: Object Sysmbol Legend

OBJECT SYMBOL LEGEND
SYMBOL DESCRIPTION
G Galaxies
P Planetary Nebula
D Diffuse Nebulae
C Globular Star Clusters
O Oben Clusters

Initially, the blinking cursor appears over the G symbol. If you decide not to look for galaxies, press the NEXT key and the symbol will change from an upper case letter (G) to a lower case letter (g), to deselect the GALAXIES category. If you wish to leave GALAXIES selected, then move the blinking cursor over to one of the other category symbols by pressing the W or E key on the Keypad. You can then deselect the undesired categories.

If you wish to recall a category symbol, move the blinking cursor over the symbol and press the PREV key. After your selections are made, press ENTER.

[ toc ] b) BETTER

The BETTER menu file option allows you to define the visual object quality range. At power up, the range is set at the bottom of the scale on VP, when using the START FIND menu selection, it will select all objects that are very poor through super or what could be considered an "ALL" setting. The object quality symbols are:

Table 6: Quality Symbol Legend

QUALITY SYMBOL LEGEND
SYMBOL DESCRIPTION
SU Super
EX Excellent
VG Very Good
G Good
FR Fair
PR Poor
VP Very Poor

If you wish to define the visual object quality range to very good and better, press the ENTER key until the symbol VG is displayed. From the VP setting to VG requires three ENTER key presses. The LX200 will now select objects that look Very Good through Super.

[ toc ] c) HIGHER

The Higher menu file option sets the horizon setting for the telescope. At power up, the setting is 00 degrees, which assumes that you have an unobstructed line-of-site to the horizon in every direction. If, however, there are things obstructing a level horizon, or if the sky quality is poor due to haze or light pollution, you can set an artificial horizon level so that your LX200 will not try to find objects below your setting.

Enter the number of degrees above the horizon that will clear the obstructions in the sky. To roughly judge how many degrees the obstruction is taking up of the sky, merely hold your fist at arm's length. Each fist diameter is approximately 5 degrees. So, if a tree is three fists high, you would make a setting of 15 degrees in the HIGHER setting. Once the setting is finalized, press ENTER.

[ toc ] d) LARGER

The LARGER menu file option allows settings of the lower apparent size limit of the objects you wish to see. At power up it is set to 000' (arc minutes). In order to make a decision as to the size limits that you may impose, it helps to have a clear understanding of exactly what an arc minute of sky is. A good example is the apparent size of the Moon, which could be expressed as 1/2 of a degree, 30 arc minutes, or 1800 arc seconds. Each arc minute is 60 arc seconds, and there are 60 arc minutes for each degree of sky.

Some beginning observers have a tough time discerning objects less than about 1 arc minute in size unless it is a double star or a planet. Astrophotographers and those involved with CCD imaging may want to set a higher value based off of desired image scale coverage that would be most impressive with different films or types of CCD cameras. Enter the new value in arc minutes, then press ENTER to exit to the option file.

[ toc ] e) SMALLER

The SMALLER menu file option is the upper size object limit. At power up the setting is for 200' arc minutes or 3.33 degrees. This setting is high enough to cover the largest objects in the OBJECT LIBRARY. You may want to lower the value because of true field-of-view limitations of a particular eyepiece (see the RADIUS parameter option for calculating true field).

Other reasons for limiting the value in SMALLER is for astrophotographic or CCD imaging requirements where we don't want the object to exceed the imaging area of the film or the CCD chip.

[ toc ] f) BRIGHTER

The lower brightness limits based on stellar magnitude can be limited in the BRIGHTER menu file option. At power up, the magnitude value is set to a very faint level of +20.0.

You may want to adjust the magnitude level to a brighter value starting at perhaps the limiting visual magnitude of your LX200, which is approximately 14.0 for an 8" and 14.5 for a 10". If you are making astrophotographs, the limiting magnitudes are about 16.5 and 17 for the eight and ten inch instruments respectively. Sky conditions also greatly affect the limiting magnitude due to atmospheric haze, high clouds, light pollution, or combinations thereof.

[ toc ] g) FAINTER

The upper level of brightness may also be adjusted with the FAINTER menu file option, although you may find few applications for limiting it to a lower value.

[ toc ] h) RADIUS

The RADIUS value sets the boundaries of what and how many objects the LX200 recognizes is in a given eyepiece while in the FIELD menu selection. At power up the RADIUS menu file option is set to 15 arc minutes, the radius of 1/2 a degree (30 arc minutes), which is about the proper setting for a 26mm eyepiece used in an 8" f/10 LX200.

To calculate the true field of an eyepiece in the telescope, first divide the focal length of the telescope (e.g. 2000mm for an 8" f/10) by the focal length of the eyepiece (the standard supplied eyepiece is a 26mm Super Plössl, 2000 divided by 26 equals 77X magnification). Then find the apparent field of the eyepiece (which is 52 degrees for the 26mm Super Plössl) and divide it by the magnification (52 divided by 77 equals .67 degrees, multiplied by 60 equals 40.2 arc minutes).

To get the radius of the true field of view, divide the true field by 2. In the case of the above equation, 40.2 arc minutes divided by 2 equals 20.1 arc minutes.

[ toc ] 2. Mode Two: COORDINATES/ GO TO

Mode two allows you to see where you have pointed the LX200 in two celestial coordinate formats, either Right Ascension and Declination or Altazimuth. Also in this mode you can enter new Right Ascension and Declination coordinates for any sky position, perhaps to locate objects not in the LX200 library such as comets or asteroids and have your telescope slew to the new coordinates.

[ toc ] a. Coordinates Menu File

You will at first see the RA = and DEC = coordinates of where the telescope is pointing. If you move the LX200 with the N,S,W,or E keys, the coordinates display will immediately update the new position in Right Ascension and Declination.

You can also display computed information of the Altazimuth coordinates (ALT = and AZ =) by pressing the ENTER key. To return to RA = and DEC =, press the ENTER key again.

The RA = display is broken down into hours, minutes, and seconds, and the DEC = display is broken down into + for North Declination and - for South Declination into degrees, minutes and seconds as shown in Display 29:

If you have made an ALTAZ style of alignment, the ALT = and AZ = coordinate display is formatted so that 0 degrees Azimuth (AZ =) is due South that increases to up to 359 degrees, 59 minutes, and 59 seconds moving clockwise, or from due South moving Westerly. Altitude (ALT =) is formatted so that straight overhead is +90. degrees and 00 minutes, decreasing to +00. degrees, 00 minutes, and 00 seconds as you move the telescope level with the horizon, and then as the LX200 moves below +00:00:00 it will give minus Altitude readings. The Altazimuth coordinate display is shown in Display 30:

While in ALTAZ, you will find during slewing in one direction, that both the RA= and DEC= display will change at the same time, while the ALT= and the AZ= display will only change in the direction that the telescope is being slewed. It is also important to note that only the Declination Setting Circle (3, Fig. 3) will give a correct reading. The R.A. Setting Circle (10, Fig. 3) will only give correct readings in the POLAR setting (see Appendix B: Equatorial Use).

[ toc ] b. GO TO Menu Option

The GO TO menu option, allows you to enter new Right Ascension and Declination coordinates of any object in the sky, so that the LX200 will slew to the new position. With this ability, your LX200 knows no bounds, any celestial object, including comets, asteroids, etc. are easily found, provided you have accurate coordinate data to refer to.

To enter a new pointing position in Right Ascension and Declination, press the GO TO key and a double beep will be heard followed by a blinking cursor that will appear over the RA = coordinate numbers. At this point, type in the new Right Ascension coordinate numbers, then press the ENTER key. You will then notice that the blinking cursor is over the DEC = coordinate numbers. Enter the new Declination coordinate numbers, then press the ENTER key and the LX200 will slew to the new coordinate position.

If you need to enter a minus Declination setting, move the blinking cursor over the + symbol with the W key and then press the NEXT key to get the - (minus) symbol, then move the blinking cursor to the first number with the E key and enter the new coordinate numbers. If you are already at a minus (-) Declination setting and wish to enter a plus (+) declination setting, follow the same instructions as above but press the PREV key instead to get the + symbol.

[ toc ] c. Slew To ALTAZ Coordinates

This feature is similar to the GO TO Right Ascension and Declination coordinates option. It allows you to directly enter the altitude and azimuth coordinates and slew to this position. This also can be used in the LAND mode, allowing the automatic acquisition of land objects for commercial applications. (Note: This feature is not available in the POLAR mode.)

To slew to ALTAZ coordinates, follow these steps:

1. Go to the ALTAZ display.

2. Press the GO TO key on the Keypad. You will hear a quick double beep, and a blinking cursor will appear in the ALT display line on the Keypad display.

3. Key in the desired ALT position and hit the ENTER key. The blinking cursor will move to the AZ line.

4. Key in the desired AZ position. When the ENTER key is pressed, the telescope will slew to the new position.

[ toc ] 3. Mode Three: CLOCK/ CALENDAR

The continuously operating clock and calendar is the life pulse of your LX200. At power up, the telescope's accurate sidereal clock automatically allows the system computer to make orbital calculations of the planets, and correct stellar precession for superior pointing ability.

Your accurate initial input of local time and date, with its' long-life lithium battery back-up, need not be re-entered every time you use the LX200, thus enhancing the user friendly aspects of the instrument.

To set the local time and date and to enter the correct GMT offset, refer to section D. QUICK START, of this manual. Be sure to use your local hour setting appropriately in either 12 hour or 24 hour format as predetermined by the 12/24 HOUR TELESCOPE menu file option.

The long-life lithium battery (Panasonic CR2032 3 volt or Duracell DL2032B) is stored behind the Power Panel of the Drive Base. See Appendix E. in this manual for battery replacement information.

[ toc ] 4. Mode Four: TIMER/ FREQ

[ toc ] a. TIMER = Menu Option


The TIMER = menu option is for accurately timing different observing or imaging tasks for up to twelve hours long. Counting down to zero, in the hours, minutes, and seconds format, it will give a pleasant beeping tone to notify you that the time is up.

To set the TIMER, move the LCD arrow to TIMER= 00:00:00. Then press and hold the ENTER key to get the double beep tone and the blinking cursor. Enter the number of hours, minutes, and seconds that you require. If you need to correct an error in entry, use the E and W keys to move the blinking cursor and then type in the correct information. After entry, press the ENTER key again and the cursor will eliminate. When you are ready to start your time count-down, press the ENTER key once more. To pause the count-down press ENTER again, and then again to resume.

If you merely want an automatic 12 hour count-down, just press the ENTER key without holding. Then press ENTER to count-down.

[ toc ] b. FREQ= Menu File

FREQ= (Frequency) allows you to adjust the tracking speeds (not slew speeds) of the LX200 digitally in tenths of a hertz from 56.4 Hz to 60.1 Hz, so that you can match virtually every celestial motion in the sky. Some popular drive rate settings are:

Table 7: Drive Rate Settings

FREQUENCY RATE DESCRIPTION NOTES
60.1 Hz Q Sidereal Rate; Quartz setting Default rate at power up. Gives sidereal frequency accuracy to + or - .005%; Best for most astrophotography.
60.0 Hz Solar and Planetary rate Average rate for tracking planets; Actual rates vary due to retrogrades, oppositions, etc.
57.9 Hz Lunar rate Best for tracking the Moon.v

Note: If you have trained the Smart Drive in the 60.1 Hz Q setting (see SMART menu file in this section), you will find that Smart Drive will still give periodic error corrections in all of the other frequency settings.

There are three menu file options in FREQ=. To see or set the options, move the LCD arrow to FREQ= and press the ENTER key. At power up, the FREQ= default is the 60.1Hz Q setting. The quartz rate is precisely fixed and cannot be altered. To choose a rate other than the quartz setting, press the ENTER key to see 60.1 M and then again to see 60.1 M with the up and down LCD arrow. These two menu file options can adjust the tracking speeds. The adjustment techniques are described below:

Display 31 shows the manual rate menu file option that can be adjusted by pressing and holding the ENTER key to get the double beep tone and the blinking cursor. Type in the new rate, then when finished, press the ENTER key again.

Display 32 shows the menu file option allows you to step the drive tracking frequency setting in tenths of a hertz, by using the PREV and NEXT (up and down arrow) keys. This is a convenient feature if you are trying to match the precise speed of a planet, comet, or any other non-stellar object. To exit this option, press the MODE key.

[ toc ] 5. Mode Five: KEYPAD OFF/ BRIGHTNESS ADJUST

In order to see very faint objects, it will sometimes be necessary to either dim or completely turn off the Keypad red LED backlighting. To do so press the MODE button until the display goes blank. This is the OFF option.

To set the Keypad brightness, press the ENTER button and adjust the brightness to your satisfaction with the PREV and NEXT keys. To exit, press the MODE key.

Note: The backlighting is done by edge lighting a plastic light bar underneath the Keypad. Four LED's are used and do not give a perfectly even backlighting of the keys as keys closer to a LED will be a little brighter than those keys further away.

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