Appendix E: Maintaining Your Lx200; Keeping Your Telescope Clean - Meade LX200 Instruction Manual

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 build-
up, 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.
CAUTION: Anytime the LX200 is being stored or
transported, be sure to release the R.A. and Dec.
locks, to prevent serious damage to the drive gears.
CAUTION: Never attempt to wipe down optics that are
covered with dew. Dust and dirt may be trapped with
the collected dew, and upon wiping the optics you
may scratch them. After the dew has evaporated you
will most likely find them in fine condition for the next
observing session.
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
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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.
CAUTION: Do not use scented, colored, or lotioned
tissues or damage could result to the optics.
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 propellant (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