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A. Introducing the Meade Model 285
The Model 285 is an easy-to-operate, high performance 60mm refracting telescope,
intended for astronomical and terrestrial (land) observing. Equipped with
a deluxe equatorial mount and aluminum tripod, the telescope's motion is
continuously adjustable for tracking celestial or land objects. Your telescope
comes to you ready for adventure; it will be your companion in a universe
of breathtaking landscapes, planets, galaxies, and stars.
Figure 1: Meade Model 285 60mm (2.4") Refracting Telescope
1. Tripod legs
2. Equatorial mount
3. R.A. flexible cable control
4. Dec. flexible cable control
6. Counterweight shaft
7. Counterweight lock
8. Safety washer/knob
9. Latitude lock
10. Polar axis
11. Latitude adjustment knob
12. Telescope optical tube assembly
13. Saddle plate for mounting optical tube
14. Optical tube mounting wing-nuts
15. Optical tube mounting bolts
16. Diagonal mirror
18. Focuser thumbscrew
20. Diagonal thumbscrew
21. Declination axis
22. R.A. lock
23. Dec. lock
24. 5 x 24 viewfinder
25. Viewfinder bracket
26. Viewfinder bracket thumbscrews
27. R.A. setting circle
28. Dec. setting circle
29. Latitude dial
30. Azimuth lock
31. Focus knobs
32. Polar shaft acorn cap nut
33. Azimuth base
34. Azimuth shaft bolt
35. R.A. worm block assembly
36. Dec. worm block assembly
37. Dew shield
38. Objective lens cell
39. Accessory shelf with attachment knob
40. Leg braces
41. Front lens dust cover
42. Adjustable sliding leg extension
43. Sliding inner leg extension thumbscrew lock
44. Tripod-to-mount attachment bolts
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1. This Manual
These instructions detail the set-up, operation, specifications, and optional
accessories of your Meade Model 285. In order that you may achieve maximum
enjoyment of the instrument, we urge that you take a few minutes to read
all of this manual before making first observations through the telescope.
As you read this manual, the technical terms associated with telescopes
will be made clear.
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2. Standard Equipment
Complete optical tube assembly with 60mm diameter, multi-coated objective
lens, dew shield, mounting hardware, 5 x 24 viewfinder with bracket, and
rack-and-pinion focuser. Lens focal length = 900mm; f/15.
Equatorial mount with pre-attached, continuously adjustable, aluminum
tripod and leg braces.
MA 25mm (36x) and MH 9mm (100x) eyepieces (1.25" O.D. )
Hybrid diagonal mirror (fits into the telescope's .965" focuser, and
accepts 1.25"-barrel diameter eyepieces)
Counterweight with counterweight shaft
Flexible cable controls for both telescope axes
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B. Unpacking and Assembly
(Numbers in brackets below refer to Fig. 1)
Your Meade Model 285 comes to you packaged almost entirely pre-assembled.
You will find upon opening the giftbox that there are two compartments within
that contain the optical tube assembly and the tripod with equatorial mount.
The accessories described above will be located within compartments custom-cut
into the styrofoam block inserts. (References hereine.g.,(6)are
to Fig.1 unless otherwise specified.)
(1) Remove and identify the telescope's Standard Equipment listed in Section
(2) Spread the tripod legs (1) to full extension so that the leg braces
are taut (should one of the tripod leg braces slip out of the center triangle
fastener, merely reposition the brace and slide it back into position).
Adjust the tripod with the attached equatorial mount (2) to the desired
height by loosening the tripod lock knobs and extend the sliding inner section
of each tripod leg; then tighten each knob. Note that these knobs need only
be tightened to a "firm feel." Overtightening the tripod lock
knobs can result in damage to the knob or the tripod leg itself.
(3) Remove the mounting knob from the round accessory shelf. Place the accessory
shelf on top of the center triangle leg brace fastener of the tripod so
that the threaded stud protruding from the bottom of the shelf passes through
the hole in the center. Then replace and tighten the accessory shelf mounting
(4) Attach the flexible cable controls (3) and (4). These cable controls
are secured in place with a firm tightening of the thumbscrew located at
the end of each cable.
(5) Holding the counterweight (5) firmly in one hand, slip the counterweight
onto the counterweight shaft (6). Attach the counterweight (5) and counterweight
shaft (6), by supporting the unlocked (7) counterweight firmly in one hand,
while threading the counterweight shaft into the base of the Declination
axis of the telescope's equatorial mount with the other (see Fig. 1). Once
firmly attached, slide the counterweight to about 3" from the bottom
of the counterweight shaft (approximate balance point) and secure it in
place with the thumbscrew lock (7) of the counterweight. Note: If the counterweight
ever slips, the secured threaded safety washer/knob (8) will not let the
weight slide entirely off the counterweight shaft. Be certain that this
safety washer/knob is always in place.
(6) Attach the viewfinder bracket (25) to the telescope using the 2 thumbscrews
provided. These thumbscrews are pre-threaded into the main telescope tube
at the viewfinder location. The thumbscrews fit through the 2 holes located
at the base of the viewfinder bracket and thread into the main tube. Orient
the placement of the bracket as seen in Fig. 1. Place the viewfinder (24)
into the viewfinder bracket rings by backing off the thumbscrews (26). Then
center the viewfinder in both bracket rings using the thumbscrews on each
bracket ring. Orient the viewfinder so its front objective lens is pointing
in the same direction as the telescope's objective lens (38).
(7) Release the latitude lock (9) of the equatorial mount, and tilt the
polar axis (10) of the telescope to roughly a 45° angle by turning
the latitude adjustment knob (11). With the polar axis thus tilted, firmly
re-tighten the latitude lock.
(8) Remove the wing-nuts (14) from the optical tube mounting bolts (15)
that are on the underside of the optical tube (12) of the telescope. Then
lay the telescope optical tube assembly onto the saddle plate (13), passing
the mounting bolts (14) through the holes in the saddle of the mount. Re-attach
the wing-nuts to the mounting bolts, and tighten to a firm feel. Be sure
the objective lens (38) of the tube is on the same side of the saddle plate
(13) as Declination slow-motion control (4).
(9) Insert the diagonal mirror (16) into the focuser (17), and tighten the
focuser thumbscrew (18), to secure the diagonal mirror.
(10) Insert the MA25mm eyepiece (19) into the diagonal mirror, and tighten
the diagonal thumbscrew (20) to secure the eyepiece.
The telescope is now fully assembled. Before it can be properly used, however,
the telescope must be balanced and the viewfinder aligned.
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1. Balancing the Telescope
In order for the telescope to move smoothly on its mechanical axes, it must
first be balanced about the 2 telescope axes: the polar axis (10) and the
Declination axis (21). All motions of the polar aligned telescope (more
on this later) take place by moving about these two axes, separately or
simultaneously. To obtain a fine balance of the telescope, follow the method
(Note: if the counterweight is positioned as recommended on the previous
pagethe telescope is already approximately balanced.)
Loosen the R.A. lock (22) and rotate the telescope so that the counterweight
shaft (6) is parallel to the ground (horizontal).
Slide the counterweight (5) along the counterweight shaft (6) until the
telescope remains in one position without tending to drift down in either
direction. Then tighten the counterweight lock knob (7), locking the counterweight
The telescope is now properly balanced.
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2. Alignment of the Viewfinder
The wide field of view provided by the 5 x 24mm viewfinder permits easy
object sighting prior to observation in the higher-power main telescope.
The 5 x 24 viewfinder (24) and viewfinder bracket (25) must be attached
to the main telescope tube as in Fig. 1.
In order for the viewfinder to be functional, however, it must be aligned
to the main telescope, so that both the viewfinder and main telescope point
at the same position in the sky. With this simple alignment performed, finding
objects is greatly facilitated, since you will first locate an object in
the wide-field viewfinder, then you will look in the eyepiece of the main
telescope for a detailed view. To align the viewfinder follow these steps:
(1) Remove the telescope front dust cover (41).
(2) Place the low-power (MA25mm) eyepiece into the focuser of the main telescope.
(3) Loosen the R.A. lock (22) and the Dec. lock (23) just enough so that
the telescope turns freely on both axes. Next, point the main telescope
at some well-defined land object (e.g. the top of a telephone pole)
at least 200 yards distant. Then re-tighten the R.A and Dec. axes locks.
Turn the flexible cable controls, (3) and (4), to center the object in the
(4) With the front of the viewfinder (see Fig. 1) already centered in the
front bracket ring, look through the viewfinder and loosen or tighten, as
appropriate, one or more of the rear viewfinder bracket ring thumbscrews
(26) until the viewfinder's crosshairs are likewise centered on the object
previously centered in the main telescope.
(5) Check this alignment on a celestial object, such as a bright star or
the Moon, and make any refinements necessary, using the method outlined
With this alignment performed, objects first located in the wide-field of
the viewfinder will also be centered in the main telescope's field of view.
(Note: The viewfinder presents an image which is upside-down; this is customary
in all astronomical viewfinders.)
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C. Understanding Celestial Movements and Coordinates
To line up the Model 285 with the pole, follow this procedure:
1) Release the Azimuth lock (30) of the Azimuth base (33), so that the entire
telescope-with-mounting may be rotated in a horizontal direction. Rotate
the telescope until the polar axis (10) points due North. Use a compass
or locate Polaris, the North Star (see Fig.
3), as an accurate reference for due North.
2) Level the mount, if necessary, by adjusting the heights of the three
3) Determine the latitude of your observing location by checking a road
map or atlas. Release the latitude lock (9) and tilt the telescope mount
by turning the latitude adjustment knob (11) so that the pointer indicates
the correct latitude of your viewing location on the latitude dial (29).
Re-tighten the latitude lock (9).
4) If steps (1) - (3) above were performed with reasonable accuracy, your
telescope is now sufficiently well-aligned to the North Celestial Pole for
Once the mount has been polar-aligned as described above, the latitude angle
need not be adjusted again, unless you move to a different geographical
location (i.e. a different latitude). The only polar alignment procedure
that needs to be done each time you use the telescope is to point the polar
axis due North, as described in step (1) above.
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D. Using the Telescope
With the telescope assembled, balanced and polar aligned as described above,
you are ready to begin observations. Decide on an easy-to-find object such
as the Moon, if it is visible, or a bright star to become accustomed to
the functions and operations of the telescope. For the best results during
observations, follow the suggestions below:
To center an object in the main telescope, slightly loosen the telescope's
R.A. lock (22) and Dec. lock (23). The telescope can now turn freely on
its axes. Use the aligned viewfinder to first sight-in on the object you
wish to observe; with the object centered on the viewfinder's crosshairs,
re-tighten the R.A. and Dec. locks.
Always start an observation with the lower power MA 25mm eyepiece; get
the object well-centered in the field of view and sharply focused. Then
try the next step up in magnification. If the image starts to become fuzzy
as you work into higher magnifications, then back down to a lower power;
the atmospheric steadiness is not sufficient to support high powers at the
time you are observing. Keep in mind that a bright, clearly resolved but
smaller image will show far more detail than a dimmer, poorly resolved larger
image. The MA 25mm eyepiece included with the Model 285 presents a wide
field of view, ideal for general astronomical observing of star fields,
clusters of stars, nebulae, and galaxies; it is also probably the best eyepiece
to use in the initial finding and centering of any object.
Once centered, the object can be focused by turning one of the knobs of
the focusing mechanism (31). You will notice that the astronomical object
in the field of view will begin to slowly move across the eyepiece field.
This motion is caused by the rotation of the Earth on its axis, as described
in Section C, although the planets and stars, are, for practical purposes,
fixed in their positions in the sky. The platform on which the telescope
is sitting ( the Earth) rotates once every 24 hours under these objects.
To keep astronomical objects centered in the field of the polar aligned
telescope, simply turn the R.A. flexible cable control (3). These objects
will appear to move through the field more rapidly at higher powers. Note:
the Declination flexible cable control is used only for centering purposes,
and not for tracking.
Avoid touching the eyepiece while observing through the telescope. Vibrations
resulting from such contact will cause the image to move. Likewise, avoid
observing sites where ground-based vibrations may resonate the tripod. Viewing
from the upper floors of a building may also introduce image movement.
You should allow a few minutes to allow your eyes to become "dark
adapted" before attempting any serious astronomical observations. Use
a red filtered flashlight to protect your night vision when reading star
maps or inspecting the components of the telescope.
Avoid setting up the telescope inside a room and observing through an
open window (or worse yet, a closed window). Images viewed in such a manner
may appear blurred or distorted due to temperature differences between inside
and outside air. Also, it is a good idea to allow your telescope a chance
to reach the ambient (surrounding) outside temperature before starting an
Avoid viewing objects low on the horizon. Objects will appear better
resolved with far greater contrast when viewed higher in the sky. Also,
if images appear to "shimmer" in the eyepiece, reduce power
until the image steadies. This condition is caused by air turbulence in
the upper atmosphere.
We repeat the warning stated at the outset of this manual: Never
point the telescope directly at or near the Sun at any time! Observing the
Sun, even for the smallest fraction of a second, will result in instant
and irreversible eye damage, as well as physical damage to the telescope
The Meade Model 285 may be used for a lifetime of rewarding terrestrial
and astronomical observing, but basic to your enjoyment of the telescope
is a good understanding of the instrument. Read the above instructions carefully
until you understand all of the telescope's parts and functions. One or
two observing sessions will serve to clarify these points forever in your
The number of fascinating objects visible through your Meade refractor is
limited only by your own motivation. Astronomical software such as Meade's
Epoch 2000, or a good star atlas such as the Meade Star Charts
will assist you in locating many interesting celestial objects. These objects
- Cloud belts across the surface of the planet Jupiter.
- The 4 major satellites of Jupiter, visible in rotation about the planet, with the satellite positions changing each night.
- Saturn and its famous ring system, as well as several satellites of Saturn, much fainter than the major satellites of Jupiter.
- The Moon: A veritable treasury of craters, mountain ranges and fault lines. The best contrast for viewing the Moon is during its crescent phase. The contrast during the full Moon phase is low due to the angle of illumination.
- Deep-Space: Nebulae, galaxies, multiple star systems, star clusters hundreds of such objects are visible through the Model 285.
- Terrestrial objects: Your Meade Model 285 may be used for high-resolution
land viewing. In this case note that the diagonal mirror results in an image
which is reversed left-for-right, but which is correctly oriented up and
down. For a fully-corrected image, the optional Meade #931 Hybrid 45° Erect-Image
Roof Prism (.965" / 1.25") is required. Terrestrial observations
should almost always be made using a low-power eyepiece (50X or less), for
bright sharp images. Beyond the 50X limit images may appear very poor due
to the fact that the images are being viewed through the thickest and most
turbulent part of the atmosphere, unlike astronomical observations made
by pointing the telescope up and through a thinner atmosphere.
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E. Using Setting Circles
Setting circles of the polar aligned equatorial mount can facilitate the
location of faint celestial objects not easily found by direct visual observation.
To use the setting circles, follow this procedure:
Use a star chart or star atlas, and look up the celestial coordinates,
Right Ascension and Declination (R.A. and Dec.), of an easy-to-find bright
star that is within the general vicinity of the faint object you wish to
Center the determined bright star in the telescope's field of view.
Manually turn the R.A. setting circle (27) to read the R.A. of the object
now in the telescope's eyepiece.
The setting circles are now calibrated (the Dec. setting circle (28) is
factory calibrated). To locate a nearby faint object using the setting circles
determine the faint object's celestial coordinates from a star chart, and
move the telescope in R.A. and Declination until the setting circles read
the R.A. and Dec. of the object you are attempting to locate. If the above
procedure has been carefully performed, the faint object will now be in
the vicinity of the telescope's field of view with a low power
The R.A. Setting Circle must be manually re-calibrated on the current
Right Ascension of a star manually every time the telescope is set up, and
reset to the centered object's R.A. coordinate before moving to a new R.A.
coordinate setting. The R.A. Setting Circle has two sets of numbers, the
inner set is for southern hemisphere, while the outer set of numbers (the
set closest to the R.A. gear), is for use by observers located North of
the Earth's equator (e.g. in North America).
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F. Calculating Power
The power, or magnification of the telescope depends on two optical characteristics:
the focal length of the main telescope and the focal length of the eyepiece
used during a particular observation. For example, the focal length of the
Model 285 telescope is fixed at 900mm. To calculate the power in use with
a particular eyepiece, divide the focal length of the eyepiece into the
focal length of the main telescope. For example, using the MA 25mm eyepiece
supplied with the Model 285, the power is calculated as follows:
Meade Instruments manufactures several types of eyepiece designs
that are available for your telescope. The type of eyepiece has no
bearing on magnifying power but does affect such optical characteristics
as field of view, flatness of field, eye-relief, and color correction.
The maximum practical magnification is determined by the nature of the object
being observed and, most importantly, by the prevailing atmospheric conditions.
Under very steady atmospheric "seeing," the Model 285 may be used
at powers up to about 225x on astronomical objects. Generally, however,
lower powers of perhaps 75x to 180x will be the maximum permissible, consistent
with high image resolution. When unsteady air conditions prevail (as witnessed
by rapid "twinkling" of the stars), extreme high-power results
in "empty magnification," where the object detail observed is
actually diminished by the excessive power.
Optional accessory eyepieces are available both to increase and decrease
the operating power of the telescope. If the Model 285 is used
on a regular basis, a selection of four to five eyepieces is a worthwhile
investment to get the most performance from your telescope. For example,
an eyepiece assortment of focal lengths 32mm** or 40mm, 25mm*, 12mm, 9mm*,
and 5mm yields a magnifying range of 28x or 22.5x, 36x, 72x, 100x, and 180x
When lens cleaning does become necessary, use a camel's hair
brush or compressed air gently to remove dust. If the telescope's dust cover
is replaced after each observing session, cleaning of the optics will rarely
be required. Note: remove the dew shield (37) to access the objective lens
(38) for cleaning.
Every Meade Model 285 equatorial mount and tripod is factory inspected for
proper fit and function prior to shipment. It is unlikely that you will
need to adjust, or tighten these parts after receipt of the telescope. However,
if the instrument received unusually rough handling in shipment, it is possible
that some of these assemblies can be loose. To make adjustments you will
need a 1/2" or 11/16" socket or adjustable end wrench, a 5/64"
hex wrench, and a Phillips-head screwdriver.
The equatorial mount has four main areas that can be adjusted: A loose polar
shaft can be tightened by releasing a 5/64" hex set-screw that is on
the side of the 11/16" polar shaft acorn cap nut (32), and then turning
the 11/16" acorn cap nut clockwise to a firm feel, and then tightening
the 5/64" hex set-screw. A loose Azimuth base (33), can be tightened
by turning the 11/16" Azimuth shaft bolt (34), that is located underneath
the mount and in between the three tripod legs, clockwise to a firm feel.
The R.A. (35), and Dec. (36) worm block assemblies can have backlash removed
by releasing the 2 Phillips-head screws on each assembly, applying pressure
to the worm block against the worm gear, and then tightening the Phillips-head
screws. Note that overtightening of any of the nuts, bolts, or screws can
inhibit the smooth rotating action of the axes and gears, and may result
in stripping the threads.
The tripod legs have 1/2" nuts that may have backed off; these should
also be tightened to a firm feel.