Assembling and Operating Duke’s Meade LX200GPS SCT
These instructions will guide you through the steps of using our telescopes. You can use them to prepare for observation sessions, or print and carry them with you for reference. They are very detailed and somewhat long – if you produce a useful digest for yourself please consider sharing it with others. The copious all-caps red ink reflects my intense desire that these devices continue to serve us for years.
The directions are broken up into instructions for assembling; aligning; operating; and finally disassembling the telescope at the end of the evening.
Open the telescope storage box, remove top foam insert. KEEP YOUR FINGERS CLEAR OF THE WOODEN CRATE WALLS TO AVOID PAINFUL SPLINTERS UNDER NAILS. Place the insert where it will not collect dirt, leaves, etc.
Remove the pier bolt from the box containing the power supply. Lift the telescope out of the box by the carrying handles and place it on the pier.. THE TELESCOPE IS TO BE HELD UP ONLY BY THE HANDLES. DO NOT RELEASE THE HANDLES UNTIL THE TELESCOPE IS SECURED TO THE PIER!!!! Have a team member insert the pier bolt into the hole in the pier. You will probably not have the telescope perfectly aligned to the pier and the bolt may not find the threaded hole in the drive base (Fig. 3-17). To align the hole in this case you may gently move the telescope, taking care not to allow it to fall off the pier. When you have alignment you can insert the bolt deeper into the threaded hole and begin to tighten it. Directions are confusing on a bolt pointing up – find a way to remember them. The bolt may stick in the thread, requiring a small realignment of the telescope on the pier. Do not release the handles until the bolt is securely tightened! IF YOU HAVE TROUBLE WITH THIS STEP CALL FOR HELP. WE FAR PREFER HELPING YOU LIFT TO PICKING UP DROPPED TELESCOPES!!
When the bolt is almost tight, orient the telescope so that the power panel (Fig. 3-11) faces South (use Polaris for this). Tighten bolt securely.
Gently remove the plastic bag covering the telescope, and place it inside the box in the space formerly occupied by the telescope.
Loosen the declination lock knob (Fig. 3-2) and rotate the telescope until the optical tube is roughly horizontal. Tighten the declination lock knob. Release the R.A. lock (Fig. 3-7) and pivot the telescope until you encounter a stop. Do not force this, instead turn the telescope back 180 degrees and ccontinue until the tube points roughly North (the rear aperture will be above the power panel). Tighten the R.A. lock. FROM THIS MOMENT ON, THE DECLINATION AND R.A. LOCKS ARE NOT TO BE RELEASED! ALL TELESCOPE MOTION WILL BE PERFORMED BY THE DRIVE GEAR AND CONTROLLED THROUGH THE CONTROLLER ONLY!!!
Remove the large dust cap covering the telescope’s front aperture, and place it on the plastic bag in the box.
Plug the keypad hand controller (Fig. 3-12) cable into the receptacle marked HBX in the power panel and place the controller gently on the ground. The controller can safely rest there while the telescope slews.
Remove the viewfinder (Fig. 3-1,2,18) (small telescope) from its cavity in the foam, remove the plastic bag covering it and its lenscap, and replace bag and cap in the viewfinder’s cavity. Place the viewfinder in front of the viewfinder bracket on the top of the optical tube. Ensure that the set screws in the bracket are loosened, and slide the viewfinder into the bracket. Hand-tighten the set screws.
Remove the microfocuser (large assembly with helical cord) from its cavity in the foam. Remove the small dust cap covering the telescope’s rear aperture and place it in the plastic bag containing the microfocuser. From the bag, extract the adapter ring and thread it onto the rear aperture of the optical tube.
Ensure that the set screws on the microfocuser are loosened (these are the three large thumbscrews protruding from the assembly at 120° intervals. They are absent from the figures because they were added at Duke), then slide it over the adapter ring, with the large boxlike part facing up and the hand screws facing out. Gently tighten the three set screws to fasten the microfocuser to the adapter ring. Return the plastic bag with the dustcap to the microfocuser’s cavity in the foam.
Plug the helical cord into the receptacle marked FOCUS on the power panel. This is the topmost of three identical receptacles. BE SURE YOU HAVE CORRECTLY IDENTIFIED THE FOCUS RECEPTACLE!!!
Remove the diagonal prism (Fig. 3-13) from its small cavity in the foam. Loosen the hand screw on the right-hand side of the microfocuser (when facing the telescope's rear) and slide the metal-plated side of the prism into the microfocuser. DO NOT FORCE THE PRISM IN, LEAVE A SMALL GAP! Tighten the hand screw to fix the prism in place.
Remove the eyepiece (Fig. 3-14) from its cavity in the foam; remove the eyepiece from its protective canister and return the canister to the cavity. Loosen the hand screw in the prism and slide the eyepiece into the prism, LEAVING A SMALL GAP. Tighten the hand screw to fix eyepiece in place.
Make sure no packaging parts remain lying around, then return the top foam insert and close the storage box. This keeps the foam dry and the lid serves as a handy field desk.
Plug the power supply into the socket in the base of the pier, and insert the power cable into the receptacle marked Power in the power panel.
You have now completed assembly. BEFORE POWERING THE TELESCOPE UP, CALL AN INSTRUCTOR TO VERIFY THAT ALL COMPONENTS ARE CORRECTLY ASSEMBLED AND CONNECTED.
Switch the telescope on. The handbox display will read Welcome to AutoStar. Allow the telescope to perform its start-up functions.
When the display reads Press 0 to align or Mode for Menu press 0.
The telescope will begin its alignment process. The telescope will use its GPS receiver to establish its precise location as well as the exact time. It will then slew to several positions to measure the orientation of the mount. This complete, the telescope will attempt to point North (using a magnetic compass and its map of local deviations of magnetic from true North). No user input is required in this process. You should take advantage of this time to make preparations for observing, orient yourself to the sky, and try to locate the targets you plan to observe (or their positions, if they are too faint to see). You can also begin to fill out your observation report.
Finally, the telescope will choose a first star to align on, slew to point towards that star, and beep. The display will read Ctr Brightest Star: Press ENTER. DO NOT PRESS ENTER WITHOUT INSTRUCTOR PERMISSION. What is going on is that the North-finding capability is limited and the alignment is rarely perfect. The telescope tries to point at a star, but will usually miss it, often by quite a bit. Using the four arrow keys near the top of the controller keypad, you need to move the telescope until the selected star is centered in the field of view. You will need to change the slew speed from the default setting. Depending on how far you need to move you will want to set the speed to 6 or 7. Often the star is not even in the field of view; to find it use the viewfinder first. If you are not sure which star you are looking for, press the ? key (lower right of keypad) to display the name of the star the telescope is trying to aim at. Find the star and center it in the viewfinder using the reticle (cross-hairs). Then you should see the star in the telescope’s (much smaller) field of view and can center it there. When you think you have the right star centered, or if you are stuck, CALL AN INSTRUCTOR TO VERIFY THAT YOU HAVE CORRECTLY CENTERED THE RIGHT STAR or for help in finding the correct star.
Press ENTER when the star is centered; the computer will select a second alignment star and step 4 will repeat for this star. Using the deviations of these two stars from where it “thought” they should be the computer will attempt to compute a correction to its self-alignment. If the procedure was followed correctly, the display will soon read: Align Successful. Any other display is cause to call an instructor for help.
The display will soon change to Press 0 for Tour or MODE for menu. Press MODE to avoid being trapped in the telescope's Guided Tour mode. You are now ready to begin observing!
THERE ARE A NUMBER OF KNOBS AND SCREWS ON THE TELESCOPE THAT HAVE NOT BEEN MENTIONED HERE. THIS IS BECAUSE YOU SHOULD HAVE NO CAUSE TO TOUCH OR MANIPULATE THEM. IF YOU ARE NOT SURE WHAT A PARTICULAR KNOB DOES, PLEASE ASK BEFORE TOUCHING IT. IT IS QUITE EASY TO HARM THE OPTICS, AND EVEN EASIER TO RUIN ALIGNMENT, REQUIRING A REPETITION OF THE PROCEDURE YOU JUST COMPLETED.
Operating these telescopes via the controller menus is quite straightforward and we will acquire a familiarity with the various functions as we use them. You can find the full Operating Manual on the observatory website. A few general notes here:
PLEASE REMEMBER THAT ALL TELESCOPE FUNCTIONS ARE TO BE CONTROLLED EXCLUSIVELY THROUGH THE CONTROLLER. DO NOT TOUCH ANY KNOBS AFTER THE TELESCOPE HAS BEEN SET UP.
The telescope is operated through a nested set of menus using the keypad as follows:
The two arrow keys at the bottom of the handbox are scrolling keys, used to navigate menus. The ? key between them serves as a Help key and is our way to request clarifications from the system about what is happening.
The ten numeric keys serve, of course, to enter numeric data into the system when the software is in a mode where it accepts such input. Each of these also doubles at other times as a function key, essentially a shortcut through the menu system to a particularly useful menu. These are:
The 0 key doubles as LIGHT which toggles a red utility light at the top of the handbox, turning the handbox into a somewhat feeble but dark-vision-safe flashlight.
The 1 key doubles as SPEED. The next key pressed will determine the slew speed at which the telescope moves in response to the arrow keys. We will typically use a relatively high speed of 7 for the large-magnitude motions needed during alignment. For finer motions we use a lower speed of 4 or 5. At the end of alignment we leave the slew speed at the low setting.
The 2 key doubles as CALDWELL. After this is keyed, the numeric input following will be interpreted as a number in the Caldwell catalog.
The 3 key doubles as M. After this is keyed, the numeric input following will be interpreted as a number in the Messier catalog.
The 4 key doubles as FOCUS. When keyed, the telescope goes into Focus mode. The four directional arrow keys near the top of the handbox will now control not the direction the telescope points but the position of the prism (using the autofocuser motor). The speed at which the prism moves can be set by using the scroll arrow keys. For most of our applications, FAST is quite precise enough. When done focusing, return to normal operation by keying FOCUS again.
The 5 key doubles as SS (Solar System). Keying this lists Solar System objects, including planets, the Moon, and asteroid and comet submenus.
The 6 key doubles as STAR. Keying this brings up a menu of star catalogs you can use to find a specific star. Many of the brightest stars appear in the NAMED catalog, for others you can use the HIP(parchus) or others.
The 7 key can be used to control an illuminated reticle. Since we don't have these, we will not need that key.
The 8 key doubles as IC (index catalog). When keyed, the numeric input following will be interpreted as a number in this catalog of deep sky objects, which represents objects discovered between 1888 and 1907, when it was published as two appendices to the NGC.
The 9 key doubles as NGC (new general catalog). When keyed, the numeric input following will be interpreted as a number in this catalog of deep sky objects, which represents objects discovered by 1888.
The four arrow keys near the top of the handbox serve to move the telescope.
The ENTER key, as one would expect, serves to confirm a selection.
The MODE key serves to “pop” up one level in the hierarchical menu system, much the way an exit or esc key on a cell phone might. To exit some situations, such as the Guided Tour you may need to hold this down for a few seconds.
The GOTO key causes the telescope to slew to the target currently selected. When done slewing the telescope will beep. Keying GOTO at this time initiates a spiral search procedure, in which the telescope moves slowly in a spiral pattern around its current direction. This can be useful in searching for an object that is not in the field of view. To stop the spiral search use the MODE key.
YOU WILL BECOME FAMILIAR WITH TELECOPE FUNCTIONS THROUGH USE. IF AT ANY POINT YOU ARE NOT COMPLETELY SURE WHAT TO DO, ASK RATHER THAN GUESS. PLEASE.
Once the observation session has ended, begin by setting the power switch to off. Next, proceed to dismantle the telescope, undoing steps 15-2 inverting the order of assembly. If, however, you choose to unplug the controller before taking out the eyepiece and prism that is absolutely ok.
As you take each component out, ensure that ALL SCREWS HOLDING IT ARE PROPERLY LOOSENED before pulling it off and scratching the telescope body. Avoid over-loosening screws to prevent them falling and getting lost in the dark.
Put each component back in its plastic bag in the correct cavity in the foam.
Replace the main lens cap on the telescope and then swing it back to its initial vertical position by releasing the declination lock knob. If there is the extra piece of foam, wedge it between the lens cap and the mount base. Partially tighten the knob to gently lock the telescope in this position.
After removing all components, loosen the R.A. lock and rotate the telescope 90° to the right so that the carrying handles are on your left when you face the power panel. Partially tighten the lock. Loosen the pier bolt while someone is supporting the telescope BY ITS HANDLES. Lift the telescope and place it gently into the box. The telescope will only fit in the foam insert in one particular orientation and the fit is snug then. Check for the correct orientation before you have an 80-lb. telescope in your arms and blocking your vision.
CALL AN INSTRUCTOR TO APPROVE YOUR DISASSEMBLY AND PACKING AT THIS POINT!
Place the top foam insert back over the entire telescope and its components, and close the telescope storage box.