Meade Instruments Corporation
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Meade Apochromatic Refrators Instruction Manuals
Models 102ED, 127ED, 152ED, and 178ED
 D. MAINTENANCE
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.
[ toc ] 1. Keeping Your Telescope Clean

Prevention is the best recommendation that a telescope owner can follow in keeping astronomical equipment in top working order. Proper measures taken during observations and when storing the equipment between observation runs can add many years of trouble free use.

Dust and moisture are the two main enemies to your instrument. When observing, always use the Dew Shield (1, Fig. 4). The Dew Shield not only helps prevent dew from forming, and dust from settling on the 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 dew is allowed to evaporate from the instrument, accomplished by setting up the telescope indoors with the dust covers removed.

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 the optics in fine condition for the next observing session.

If you live in a very moist climate, you may find it necessary to use silica dessicant 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 silica dessicant as often as necessary.

Those living in coastal areas or tropic zones should also cover the electronic ports on the optional Power Panel and the Keypad with gaffers tape to reduce corrosion on the metal contacts. Apply a dab of a water displacement solution (such as WD-40) with a small brush on all of the interior metal contacts and the input cord metal contacts. The Keypad and all separate accessories should be kept in sealable plastic bags with silica dessicant.

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). 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 telescope 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 (such as WD-40). 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. When the objective lens of the telescope requires cleaning, the optical tube assembly should be returned to Meade Instruments, where the optics will be professionally disassembled and cleaned for a reasonable charge. Do not attempt to disassemble or clean the lenses yourself. Disassembling, cleaning, reassembling, and collimating an apochromatic lens is a task properly performed only by specially-trained technicians.



[ toc ] 2. Factory Servicing and Repairs

Meade apochromatic refracting telescopes have been designed and manufactured for years of trouble-free operation and repairs should rarely be necessary. If a problem does occur, first write or call our Customer Service Department. Do not return the telescope until you have communicated with us in this way, since the great majority of the problems can be handled without the return of the telescope to us. However, should the occasion arise that the instrument requires factory servicing, a Meade Instruments Customer Service Representative will issue a Return Goods Authorization (RGA) number and give you full instructions on how to use it. Returning a telescope without the RGA may greatly delay any servicing or repairs. When telephoning or writing, please explain the exact nature of the problem so that we may offer a prompt remedial procedure. Be sure to include your full name, address, phone and fax numbers where you can be reached.

Should you live outside of the United States, contact your Authorized Meade Distributor from whom you purchased the instrument.

You can reach the Meade Instruments Customer Service Department either by mail, phone, or fax at:

Meade Instruments Corporation
6001 Oak Canyon
Irvine, CA 92618-5200
U.S.A.

+1 (714) 451-1450
Fax: +1 (714) 451-1460




Table 3: Specifications and Features of Meade ED Apochromatic Refracting Telescopes
TELESCOPE: 4" Model 102ED 6" Model 127ED 6" Model 162ED 7" Model 17SED
optical Design 2-element ED Apochromat 2-element ED Apochromat. 2-element ED Apochromat 2-element ED Apochromat
Diameter 110mm 135mm 160mm 188mm
Clear Aperture 102mm (4.0") 127mm (5.0") 152mm (6.0") 178mm (7.0")
Focal Length 920mm f/9 1140mm f/9 1370mm f/9 1600mm f/9
ResolvIng Power (arc secs.) 1.1 0.9 0.74 0.64
Super Multi-Coatings on Front Element Standard, both sides Standard, both sides Standard, both sides Standard, both sides
Near Focus (approx.) 50 ft. 75 ft. 100 ft 150 ft.
Limiting Visual Magnitude 12 12.8 13.5 13.8
Limiting Photographic Magnitude 14.6 15.3 16 16.3
Image Scale 1.54°/inch 1.26°/inch 1.05°/inch 0.90°/inch
Maximum Practical Visual POV".OR 40OX 50OX 60OX 70OX
Actual Field with SWA 40mm Eyepiece 2.9° 2.35° 1.95° 1.67°
35mm Angular Film Coverage 1.48° x 2.11° 1. 1 9° x 1.70° 0.99° x 1.41° 0.85°x 1.21°
Optical Tube Dimensions (dia. x length) 4.5" x 31.5" 5.5" x 40.75" 7" x 51" 8" x 59.5"
Dow Shield (dis. x length) 5.5" x 5.5" 7" x 7" 8.25" x 8.5" 9.8' x 10"
Focusing Mechanism 2.7" I.D.; 4"travel 2.7" I. D.; 4" travel 2.7" I.D.; 4" travel 2.7" I.D.; 4" travel
Eyepiece-Holder 2", with 1.25" adapter 2", with 1.25" adapter 2", with 1.25" adapter 2", with 1.25" adapter
Diagonal Mirror 2" #930 2" #930 2" #930 2" #930
Equatorial Mounting LXD 650; German-type LXD 650; German-type LXD 750; German-type LXD 750; German-type
Ball Bearings 8 - 2.25" dia. 8 - 2.25" dia. 8 - 3. 1" dia. 8 - 3.1" dia.
Tripod Standard Field Tripod Standard Field Tripod Giant Field Tripod Giant Field Tripod
Tripod Legs Inner leg: 1.5" O.D.; Inner leg: 1.5" O.D.; Inner leg: 2" O.D.; Inner leg: 2" O.D.;
  Outer leg: 2" O.D. Outer leg: 2" O.D. Outer leg: 3" O.D. Outer leg: 3" O.D.
Tripod Height [Note 1] 30" - 44" variable 30" - 44" variable 40" - 50" variable 40" - 50" variable
Counterweight(s) 1 - 10 lb. 1 - 15 lb. 1 - 25 lb. 1 - 25 lb. & 1 - 12 lb.
Worm Gear Dias. RA & Dec: 2.8" RA & Dec: 2.8" RA & Dec: 3.75" RA & Dec: 3.75"
Setting Circles RA: 4"; Dec: 4.15" RA: 4"; Dec: 4.15" RA: 4.75"; Dec: 5" RA: 4.75"; Dec: 5"
Manual Slow-Motion Controls RA and Dec RA and Dec RA and Dec RA and Dec
Latitude Range 1 5° to 60° 15° to 60° 20° to 60° 20° to 60°
Optional Computer Drive System (see below) #1697 CDS #1697 CDS #1697 CDS #1697 CDS
Materials        
   Objective Lens KF3; ED/FK01 KF3; ED/FK01 KF3; ED/FK01 KF3; ED/FK01
   Optical Tube aluminum aluminum aluminum aluminum
   Equatorial Mounting aluminum castings aluminum castings aluminum castings aluminum castings
   Field Tripod chromed steel chromed steel chromed steel chromed steel
Total Net Telescope Weight (approx., with mount & tripod) 69 lbs. 78 lbs. 153 lbs. 176 lbs.
Heaviest Sub-Section for Field Assembly 23 lbs. 23 lbs. 55 lbs. 55 lbs.
Shipping Weight (approx.) 86 lbs. 96 lbs. 185 lbs. 212 lbs.

Meade ED Apochromatic Refracting Telescopes Optional Computer Drive System

OPTIONAL COMPUTER DRIVE SYSTEM: #1697 Computer Drive System (CDS)
Drive Motors 9-speed microprocessor-controlled DC servo motors in RA and Dec with Smart Drive software.
Slow Speeds 2x, 32x sidereal; 2°/sec. - 8°/sec., in 1°/sec. increments
Onboard Celestial Object Database 64,359 objects
Hand Controller Motorola 68HC05 microcontroller; 2 line x 16 alphanumeric character display; 19 button keypad, red LED backlit.
Main Controller 16MHz 68000 microprocessor; 128K program
  memory; 16K RAM; 612 byte non-volatile memory (EEROM)
Power Source [Note 2] 18 volts DC

[1] The LXD 650 mount supplied with 4" and 5" APO models adds approx. 18" to the tripod heights listed; the LXD 750 mount supplied with 6" and 7" APO models adds approx. 24" to the tripod heights listed.
[2] The #1697 CDS includes a 25 ft. power cord and adapter for operation from any standard 115v. AC outlet. For field operation of the drive system from a 12v. automobile cigarette lighter plug, the #1812 Electronic DC Adapter is available.

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