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APPENDIX E: MAINTAINING YOUR LX200
1. Keeping Your Telescope Clean
Prevention is the best recommendation that a telescope owner can follow to keep astronomical equipment in top working order. Proper measures taken during observation and when storing equipment between observing runs can add many years of trouble free use.
Dust and moisture are the two main enemies to your instrument. When observing, it is advisable to use a proper fitting dew shield. The dew shield not only prevents dew from forming, and dust from settling on the corrector plate lens, it prevents stray light from reducing image contrast.
Although dew shields go a long way to prevent moisture buildup, there can be times when the telescope optics will have a uniform coating of moist dew. This is not particularly harmful, as long as the instrument is allowed to let the dew evaporate. This can be done with a hair dryer, or just setting up the telescope indoors with the dust covers removed. It is also advisable that you let the foam lined case for the LX200 dry out indoors for a day if the night was moist. Packing your telescope away in a moist case can result in giving it a steam bath later.
If you live in a very moist climate, you may find it necessary to use silica desiccant stored in the telescope's case to ward off moisture and the possibility of fungus growing on and within the coatings of the optics. Replace the desiccant as often as necessary.
Those living in coastal areas or tropic zones should also cover the electronic ports on the power panel and the keypad with gaffers tape to reduce corrosion on the metal contacts. Apply a dab of a water displacement solution (i.e. WD-40) with a small brush on all interior metal contacts and the input cord metal contacts. The keypad and all separate accessories should be kept in sealable plastic bags with silica desiccant.
A thick layer of dust will attract and absorb moisture on all exposed surfaces. Left unattended, it can cause damaging corrosion. To keep dust at bay when observing, the telescope can be set up on a small section of indoor/outdoor carpet. If you are observing for more than one night in a row, the telescope can be left set up but covered with a large plastic bag (such as the one supplied with the telescope). The rear cell opening of the LX200 can also be sealed off to the elements by threading on the optional accessory Skylight 1A Dust Seal. Eyepieces, diagonals, and other accessories are best kept in plastic bags and stored in cases, such as the Meade #50 Accessory Case.
All of the non optical surfaces of the LX200 should be cleaned routinely with a soft rag and alcohol to prevent corrosion. The cast metal surfaces and the individual exposed screws can also be kept looking new and corrosion free by wiping them down with a water displacement solution. Take care not to smear the solution onto any optical surface, and to wipe up any excess solution with a clean dry cloth. The painted tube can be polished with a liquid car polish and a soft rag.
Surprisingly, the most common telescope maintenance error is cleaning the optics too often. A little dust on any of
the optical surfaces causes virtually zero degradation of optical performance. It should be of no concern whatsoever to see
some small particles on the inside or outside of telescope optics. Should the optics get more dust on them than you would care for, simply use a photographic grade camel hair brush with very gentle strokes. You can also blow off dust with an ear syringe (available from a local pharmacy).
There is a point, however, when the optics must be cleaned. This is when you can easily tell that there is a thin layer of fine particulates that make the optics look very slightly hazy. To clean the optics we must suggest that you make your own lens cleaning solutions, since it is impossible to know all of the ingredients used in commercial lens cleaners. Pure isopropyl alcohol (90% or better) will clean most residual film build-up on optical surfaces (and metal surfaces too).
Organic materials (e.g., fingerprints) on the front lens may be removed with a solution of 3 parts distilled water to 1 part isopropyl alcohol. A single drop of biodegradable dishwashing soap may be added per pint of solution. Use soft, white facial tissues and make short, gentle strokes. Change tissues often.
Sprayer bottles are a convenient dispenser of lens cleaning solutions onto the tissues. Use soft, white facial tissues and make short, gentle strokes. Change tissues often. If the optics are small (such as viewfinders or eyepieces), the tissue can be rolled to the appropriate thickness and then broken in half to create two cleaning wands. It is advised that you avoid many of the so-called lens cleaning papers (many which contain fiberglass), lens cloths, or chamois.
Before attempting to clean an optical surface with a liquid solution, it is very important that as much dust as possible is removed by using forced air and/or gentle strokes with a photographic grade camel hair brush. The forced air can come from a rubber ear syringe, or canned compressed air from a photographic supply store. Be sure to hold the canned air in a vertical position and try spraying compressed air on your hand before aiming at the optics to see if any of the propellent (solid material) comes out. Propellant is very difficult to remove from optics, so take care not to tip the can when using it. If you have access to a compressor hose, be sure that it is filtered to prevent oil from being sprayed on the optics.
Once you are confident that you have removed most of the dust and large particles, begin cleaning with the mixture described above. Pour or spray enough solution onto a pillow or wand of tissue until it is quite wet. If you are cleaning a corrector plate, use radial strokes with a smooth pillow of tissue, starting from the center out, using no pressure. If you are cleaning small optical surfaces, use the rolled wands of tissue starting from the edges then spiraling in to the center, again using no pressure. Never pour or spray the solution onto the corrector plate or eyepieces themselves, as the liquid may go behind or in between lenses, where it is difficult or impossible to reach. Never attempt to disassemble an eyepiece to clean the inner elements, as you will certainly not be able to properly center and re-assemble the optical train.
Use dry tissue to make the final clean up, again using no pressure. If there is still some sort of residue, repeat the procedure using the three part formula described above, again using the same cleaning techniques.
The inside surface of the corrector plate and secondary mirror may at some point become dirty due to particles falling inside the tube when removing or replacing the rear dust cover or threading on accessories. To reduce the chance of interior contamination, the Meade Skylight 1A Dust Seal is very effective. If the Dust Seal is not used, it helps to have the rear cell pointed downward when replacing the rear dust cover or attaching accessories.
Another more serious, but not damaging problem is the possibility of a hazy (usually uneven) film building up on the inside of the corrector plate. This can be caused by
