Meade LX50
Schmidt-Cassegrain Instruction Manual |
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. |
Use the following steps to
assemble your telescope. Note: Section headings list which LX50 model (7",
8", or 10") is covered under that heading.
Figure
1 Figure
2
[
toc ]1.
The Field Tripod (7", 8", and 10" LX50 Models)
The Field Tripods (Figs.
1 and 2) for Meade 7", 8", and 10" LX50 telescopes are supplied as completely
assembled units, except for the spreader bar (4, Fig. 1) and the 6 lock
knobs (2 knobs for each of the 3 tripod legs) used to adjust the height
of the tripod. These knobs are packed separately for safety in shipment.
The field tripod is used
in conjunction with the appropriate equatorial wedge (see next section
for instructions on the use of the equatorial wedge) for serious astronomical
applications. The equatorial wedge permits alignment of the telescope's
Polar Axis with the Celestial Pole (or North Star).
After removing the field
tripod from its shipping carton, stand the tripod vertically, with the
tripod feet down and with the tripod still fully collapsed (see Fig. 2).
Grasp two of the tripod legs and, with the full weight of the tripod on
the third leg, gently pull the legs apart to a fully open position.
Thread in the 6 lock-knobs
(2 on each tripod leg) near the foot of each tripod leg. Refer to Fig.
1. These lock-knobs are used to fix the height of the inner, extendible
tripod leg section. Note: "Firm feel" tightening is sufficient; over-tightening
may result in stripping of the knob threads or damage to the tripod legs
and results in no additional strength.
The spreader bar (4, Fig.
1) has been removed for shipment. To install, first remove the threaded
rod (2, Fig. 1) from the tripod head (1, Fig. 1); a small piece of plastic
holds the threaded rod in place. Remove the small plastic bag that is stapled
to the threaded rod. This bag contains the "C" clip retainer (used below)
and an extra clip.
Slide the spreader bar onto
the threaded rod (note the correct orientation as shown in Fig. 1) and
position the threaded rod back through the tripod head. Place the clip
retainer ( a "C" clip) into the slot in the threaded rod. This clip holds
the threaded rod in place. See Fig. 2.
Position the spreader bar
so that the 3 arms of the spreader bar are lined up with the 3 tripod legs.
The field tripod is now
ready to attach the equatorial wedge.
To vary the tripod height,
loosen the 6 lock-knobs, slide the 3 inner tripod leg sections out to the
desired height, and firmly re-tighten (but do not
overtighten) the
6 lock-knobs.
To collapse the tripod (after
removing the telescope and equatorial wedge) for storage, follow these
steps:
1. Rotate the spreader
bar 60° from its assembled position, so that one spreader bar arm is
located between each adjacent pair of tripod legs.
2. At the base of the tripod
is a 3-vane extension strut system, with a circular hub at its center (7,
Fig. 1). Grasp the tripod head (1, Fig. 1) with one hand and, with the
other hand, pull directly "up" on the central hub of the extension strut
system. This operation will cause the tripod legs to move inward to a collapsed
position.
PRECAUTIONARY NOTES
1. If the tripod does not
seem to extend or collapse easily, do not force the tripod legs
in or out. By following the instructions above, the tripod will function
properly, but if you are unclear on the proper procedure, forcing the tripod
into an incorrect position may damage the extension strut system.
2. Do not overtighten the
6 lock-knobs used to fix the inner tripod leg sections at various heights.
"Firm feel" tightening is sufficient.
3. Be sure the spreader
bar (4, Fig. 1) is not upside-down on the threaded rod.
[
toc ]2.
Equatorial Wedge
There are three equatorial
wedges used on Meade LX50 telescopes. Please read the section below that
applies to your telescope.
a. 7" and 8" Equatorial
Wedge (For 7" LX50 Maksutov-Cassegrain and 8" LX50 Schmidt-Cassegrain)
The Equatorial Wedge permits
use of the 7" or 8" LX50 telescope in an astronomical, or "equatorial,"
mode. The wedge fits onto the field tripod, described above, and accepts
the base of the 7" or 8" LX50 fork mount. See Fig.
3.
NOTE: The Meade equatorial
wedge is designed solely for use in conjunction with the Meade field tripod.
The wedge should never be used without the field tripod (e.g. by
placing the wedge alone on a table top and then mounting the telescope
on the wedge). The 7" or 8" LX50, placed onto the equatorial wedge alone
without the field tripod attached to the wedge may become seriously imbalanced,
to the point where the telescope may actually tip over.
The equatorial wedge for
the 7" and 8" LX50 telescope is of modern design, with several important
features incorporated to simplify and facilitate telescope operation. After
using the wedge, you will find that the functional design features included
are of very significant value in routine telescope operations. Features
included are:
1. Attachment of the wedge
to the field tripod by means of only one manual knob.
2. Quick azimuth adjustment
by loosening the manual knob as described above.
3. Bubble level for rapid
tripod/wedge leveling.
4. Etched latitude scale
for fast adjustment of the latitude angle.
To assemble the equatorial
wedge, follow this procedure (note that all required wedge hardware and
manual knobs are shipped within the wedge carton):
1. The wedge consists of
two basic parts: the wedge body and the tilt-plate, as shown in Fig.
3 Attach the tilt-plate to the wedge body by threading in the four
knobs provided. Two knobs, with washers, should be used on each side of
the wedge body so that a total of 4 knobs attach the tilt plate to the
wedge body.
2. Place the wedge onto
the field tripod with the central threaded rod of the tripod fitting through
the center hole in the floor of the wedge. Thread the 2-1/2" diameter manual
knob onto the threaded rod of the tripod and firmly tighten the manual
knob.
[
toc ]Azimuth
Control
The Azimuth Control for
the Meade Equatorial Wedge and Field Tripod is shipped in a plastic bag
and includes the following parts:
Azimuth Base (large
U shaped piece of aluminum)
Azimuth Arm (small T shaped
piece of aluminum)
2 - Azimuth Knobs
2 - 8-32 x 1/2" flat-head
machine screws
2 - 8-32 x 1" round-head
machine screws
To attach the Azimuth Control
to your wedge and tripod, follow these steps:
1. Remove the 4 set screws
from the wedge and field tripod (which plug the attachment holes) using
a screwdriver.
2. Attach the Azimuth Arm
to the Equatorial Wedge using the 2 8-32 x 1/2" flat-head machine screws.
3. Attach the Azimuth Base
to the Field Tripod using the 2 8-32 x 1" round-head machine screws.
4. Thread the two Azimuth
Adjustment Knobs into the Azimuth Base, until they just touch the Azimuth
Arm.
The Azimuth control is now
ready to use. To adjust in Azimuth, loosen the 3" central wedge knob. Rotate
the wedge by using the two Azimuth knobs in a push-pull manner. After positioning
the wedge, tighten the central wedge knob.
[
toc ]b.
Equatorial Wedge (For 10" LX50)
The Equatorial Wedge permits
use of the 10" Schmidt-Cassegrain LX50 telescope in an astronomical, or
"equatorial," mode. The wedge fits onto the field tripod, described above,
and accepts the base of the 10" Model LX50 fork mount. See
Fig. 5.
NOTE: The Meade equatorial
wedge is designed solely for use in conjunction with the Meade field tripod.
The wedge should never be used without the field tripod (e.g., by placing
the wedge alone on a table top and then mounting the telescope on the wedge).
The 10" LX50 telescope, placed onto the equatorial wedge alone without
the field tripod attached to the wedge may become seriously imbalanced,
to the point where the telescope may actually tip over.
The equatorial wedge is
of modern design, with several important features incorporated to simplify
and facilitate telescope operation. After using the wedge for your telescope,
you will find that the functional design features included are of very
significant value in routine telescope operations. Some of these features
include:
1. Attachment of the wedge
to the field tripod by means of only one manual screw.
2. Quick azimuth adjustment
by loosening the manual screw described above.
3. Bubble level for rapid
tripod/wedge leveling.
4. Etched latitude scale
for fast adjustment of the latitude angle.
Figure
4: Azimuth Control
Figure
5: Equatorial Wedge for 10" LX50 Telescope
To assemble the equatorial
wedge, follow this procedure (note that all required wedge hardware and
manual knobs are shipped within the wedge carton):
1. The wedge consists of
two basic parts: the wedge body and the tilt-plate, as shown in Fig. 5.
Attach the tilt-plate to the wedge body by means of the hex-screws provided.
Two screws, with washers, should be used on each side of the wedge body
so that a total of 4 screws attach the tilt plate to the wedge body.
2. Place the wedge onto
the field tripod with the central threaded rod of the tripod fitting through
the center hole in the floor of the wedge. Thread the 2-1/2" diameter manual
knob onto the threaded rod of the tripod and firmly tighten the manual
knob.
A fine latitude adjustment
mechanism (necessary only for precision astrophotographic polar alignment)
is included in one slot on the side of the wedge for the 8" and 10" LX50;
two of these mechanisms (one at each side of the wedge) are provided with
the wedge for the 10" LX50. Loosen the hex-screw at the side of the wedge
and slide each mechanism so that the 1-inch long screw (located just inside
the vertical wedge wall) presses up against the bottom surface of the tilt-plate.
To make fine latitude adjustments,
follow this procedure: (1) loosen slightly the screws (5), on each side
of the wedge, as shown in Fig. 5; (2) turn the screw pressing against the
bottom of the tilt-plate so that the tilt-plate moves in latitude angle;
(3) re-tighten the screws or knobs.
Use of the fine latitude
mechanisms on the wedge for the 10" LX50 requires that both mechanisms
be adjusted as just described.
[
toc ]c.
Superwedge (For 10"LX50 with Superwedge)
The Superwedge permits use
of the 10" LX50 telescope in an astronomical, or "equatorial," mode. The
wedge fits onto the field tripod, described below, and accepts the base
of the 10" LX50 fork mount. see Fig. 7.
NOTE: The Meade Superwedge
is designed solely for use in conjunction with the Meade field tripod.
The Superwedge should never be used without the field tripod (e.g., by
placing the Superwedge alone on a table top and then mounting the telescope
on the wedge). The 10" LX50, placed onto the Superwedge alone without the
field tripod attached to the wedge may become seriously imbalanced, to
the point where the telescope may actually tip over.
The Superwedge for the 10"
LX50 telescope is of modern design, with several important features incorporated
to simplify and facilitate telescope operation. After using the Superwedge
for your telescope, you will find that the functional design features included
are of very significant value in routine telescope operations. Some of
these features include:
1. Attachment of the Superwedge
to the field tripod by means of only one manual knob. (For photographic
applications with the telescope where extreme steadiness is required, 3
additional hex-head screws are provided).
2. Quick Azimuth adjustment
by loosening the manual knob as described above.
3. Bubble level for rapid
tripod/wedge leveling.
4. Etched latitude scale
for fast adjustment of the latitude angle.
5. Built-in latitude adjustment
control.
Figure
6: Superwedge for 10" LX50 Telescope
Figure
7: Mounting Superwedge
To assemble the Superwedge,
follow this procedure (note that all required wedge hardware and manual
knobs are shipped within the wedge carton):
1. Locate the two 8-32 nylon
set screws on the rim of the tripod head and remove them. Attach the tangent
arm to the tripod using the supplied 8-32 X 1/2" socket cap screws. (See
Fig. 7.)
2. Push the field tripod
threaded rod up so that the threaded rod extends above the top of the tripod
head.
3. Holding the threaded
rod in position, place the Superwedge on top of the tripod head so that
the threaded stud extending from the tripod head passes through the center
hole on the wedge floor. Make sure the pin extending from the bottom of
the azimuth thrust bar is positioned in the slot on the tangent arm (see
Fig. 7).
4. Install the large hand
knob/compass onto the threaded stud. Pass the three 5\16-18 X 1-1/4" button
head screws through the clearance slots on the wedge floor and thread them
into the tripod head.
5. The lower tilt plate
locking screws (see "A", Fig. 8) are installed in the factory to allow
the tilt plate to be adjusted for any latitude greater than 25 degrees
and less than 55 degrees. If viewing in a region with a latitude greater
than 55 degrees, move the locking bolts to the lower mounting holes (see
"B", Fig. 8).
Figure
8: Latitude Range Holes
[
toc ]Magnetic
Compass (for 10" Superwedge)
The magnetic compass helps
the observer to set-up the telescope without actually seeing the pole star
Polaris. This allows setting up before dark or in locations where the view
of Polaris is obstructed. The magnetic compass has an adjustment to compensate
for the local angle of Magnetic Declination. Note: Magnetic Declination
is the difference between Magnetic North (which the compass shows) and
true north (where the telescope should be pointed). Magnetic Declination
should not be confused with the astronomical term "Declination," which,
when used with "Right Ascension," describes the celestial coordinate system.
[
toc ]a.
Setting Magnetic Declination
In order to obtain an accurate
reading using the compass, you must first adjust for the Magnetic Declination
for your location.
1. First, determine the
Magnetic Declination in your area using the Isogonic Chart (Fig. 9).
Figure
9: Magnetic Declination Map
2. Squeeze the clear central
vial with thumb and index finger of the left hand.
3. With the right hand,
rotate the outer dial until the orienting arrow (the black arrow painted
on the inside clear surface) is lined up with the desired Magnetic Declination
angle on the declination scale. Notice that East Magnetic Declination is
to the right of the "North" position and West Magnetic Declination is left
of the "North" position. As an example, Fig.
10 shows the correct setting for 16 degrees West Declination, which
covers Providence, Rhode Island.
[
toc ]b.
Compass Installation
The Magnetic Compass is
now set for the correct declination angle. To attach to the Equatorial
Wedge, follow these steps:
1. Snap the Magnetic Compass
into the 3" diameter wedge attachment knob (after setting the Magnetic
Declination as described above). Position the compass into the knob so
that the 360 degree location on the direction scale (the "North" position)
lines up with one of the nine points of the knobs. (See Fig.
10.) Press the compass firmly into the knob.
2. Assemble the Equatorial
Wedge onto the Field Tripod as described using the knob/ compass combination
to attach the wedge to the tripod.
[
toc ]c.
Finding True North
The Magnetic Compass is
now ready to use. Just follow these simple steps for a quick and easy azimuth
alignment:
1. Loosen the knob/compass
slightly. This allows for rotation of the Equatorial Wedge under the knob/compass
(Fig. 11). The magnetic pointing arrow
will point to magnetic north.
2. Rotate the knob/compass
so that the magnetic pointing arrow lies directly over the painted black
alignment arrow (painted on the bottom surface of the compass, Fig.
12). The "North" position on the direction scale (and the point on
the knob/compass) now point directly north.
3. Rotate the Equatorial
Wedge in azimuth (without moving the knob/compass) until the centerline
of the wedge lines up with the point of the knob/compass (Fig.
13). The centerline of the Equatorial Wedge now falls directly on the
true north line.
4. Tighten the knob/compass,
locking the Equatorial Wedge into place.
The Field Tripod and Equatorial
Wedge are now pointed directly toward celestial north, without ever having
seen the North Star.
[
toc ]4.
Mounting the Telescope On the Wedge (7", 8", and 10" LX50 Models)
With 7" and 8" LX50 telescopes,
three knobs are supplied for mounting the telescope's drive base to the
tilt-plate of the equatorial wedge. With the 10"LX50, three socket screws
are provided for this purpose.
Thread one of these knobs
(or screws, as appropriate) partially into the hole on the underside of
the drive base, located at the curved-end of the drive base. See 4, Fig.
14. This knob or screw should be threaded in about 3 full turns, not
fully threaded into the hole.
Check that the knobs or
bolts at the side of the wedge, (5, Fig. 3
or 5, Fig. 5), are firmly tightened before
placing the telescope onto the wedge.
Grasping the 2 fork arms
of the telescope firmly, with the power panel towards you, place the telescope
onto the tilt plate of the wedge by sliding the knob (7" and 8" LX50) or
screw (10" LX50) into the slot at the top of the curved-end of the wedge
tilt-plate.
Insert the 2 remaining knobs
for the 7" and 8" LX50, or socket screws for the 10" LX50, through the
underside of the tilt plate and into the underside of the drive base. Tighten
down all 3 knobs or screws to a firm feel. Extreme force is not necessary
in this regard.
The telescope is now fully
mounted onto the wedge and field tripod. Adjustments in wedge latitude
angle and/or azimuth orientation may be made with the telescope in place.
Further details on telescope polar alignment see Appendix A: Equatorial
Use.
Figure
15: Underside of Drive Base
Figure
16: Telescope on Wedge
Figure
17: 8" LX50 Telescope
[
toc ]5.
Mounting the Viewfinder
Each 7", 8", and 10" LX50
telescope is supplied as standard equipment with a straight-through viewfinder.
The bracket for this viewfinder is packed separately from the finder itself,
and 6 metal thumbscrews for collimation are pre-threaded into the viewfinder
bracket. The viewfinder bracket mounts onto the telescope. See
Fig. 17.
a. Attaching the Viewfinder
Slide the viewfinder into
the bracket and lightly tighten the 6 collimation (alignment) screws (2,
Fig. 17).
b. Focusing the Viewfinder
The viewfinder has been
pre-focused at the factory. However, should it become necessary to adjust
the focus, follow these steps:
1) Loosen the Focus Lock
Ring (16, Fig. 17).
2) While looking at a star,
rotate the Dew Shield (1, Fig. 17) until the star is in focus. (This refocuses
the objective lens.) CAUTION! Take care when rotating counter clockwise.
You are unthreading the dew shield and it may fall off if rotated too far.
Refocusing the objective lens will only require a few turns of the Dew
Shield at most.
3) When the Dew Shield is
rotated to the sharpest focus for your eye, tighten the Focus Lock Ring
against the Dew Shield to fix its position.
c. Collimating the Viewfinder
The viewfinder will require
alignment, or collimation, with the main telescope. Using the 25mm eyepiece,
point the main telescope at some easy to find land object (e.g.,
the top of a telephone pole or corner of a building) at least 200 yards
distant. Center a well-defined object in the main telescope. Then, simply
turn the 6 metal collimation thumbscrews (2, Fig. 17) until the crosshairs
of the viewfinder are precisely centered on the object already centered
in the main telescope. With this collimation accomplished, objects located
first in the wide-field viewfinder will then be centered in the main telescope's
field of view.
[
toc ]6.
Attaching the Diagonal Prism and Eyepiece
The eyepiece holder (6,
Fig. 17) threads directly onto the rear-cell thread of the 7", 8" and 10"
telescopes. The diagonal prism (13, Fig. 17) slides into the eyepiece holder
of the 7", 8" and 10" telescopes. In turn, the diagonal prism accepts the
supplied 1-1/4" O.D. eyepiece.
For astronomical observations,
the diagonal prism generally provides a more comfortable right-angle viewing
position. Alternately, in the 7", 8" and 10" telescopes, an eyepiece may
be inserted directly into the eyepiece holder for straight-through observations.
Note in this case, however, that the image will appear inverted and reversed
left-for-right. With the diagonal prism, telescopic images appear correctly
oriented up-and-down, but still reversed left-for-right. For terrestrial
applications, a fully corrected image orientation is desired, both up-and-down
and left-for-right. The optional #924 Erecting Prism or #928 45° Erect-Image
Diagonal Prism should be ordered separately. Eyepieces and the diagonal
prism are held in their respective places on the telescope by a moderate
tightening of the thumbscrews on the diagonal prism and eyepiece holder.
[
toc ]7.
Checking the Collimation of the Optics
The optical systems of all
Meade Schmidt-Cassegrains are precisely collimated, or aligned, before
leaving the factory. However, if the telescope has received a severe jolt
in shipment the optics can become de-collimated, a situation which may
result in serious image degradation. Recollimating the optics is, however,
a simple procedure which is easily performed by the telescope user. We
urge all LX50 owners to confirm the collimation of their telescope, and
to recollimate the optics if necessary.
There is no collimation
procedure required for the Meade 7" Maksutov-Cassegrain telescope. Factory
alignment assures optimal viewing accuracies.
[
toc ]8.
7" Tube Swing-Through Limit
The length of the 7" LX50
optical tube prohibits the correcting plate end of the tube from swinging
through the fork arms–the tube will hit the mount. When the telescope is
aligned, the software will stop the telescope from moving into the mount.
If the telescope is not aligned, there are mechanical stops. Viewing some
parts of the sky might be restricted if using a wedge.
Observing sites with latitudes
higher than 45° will not have any restrictions. Latitudes below 45°
will have the southern horizon somewhat restricted when using a wedge and
polar aligning. To determine the amount of sky not available, subtract
the latitude of the observing site from 45, this will give the number of
degrees of the southern horizon that the 7" LX50 will not reach. For example,
if the latitude of the observing site is 35°, then 10° (45-35)
of southern sky is unavailable for observations. No restrictions of observable
sky occur in the Altazimuth mode of alignment and operation.
[
toc ]9.
Maksutov Fan
The Maksutov optical tube
assembly is equipped with a fan which will assist in the stabilization
of the temperature of the optics. The fan will operate when a special power
cord (supplied in the accessory box) is plugged into the fan and the LX50
panel plug marked "Aux," and with the power switch in the "On" position.
The amount of time required to stabilize the temperature will be dependent
upon ambient conditions including the observation site and pre-existing
condition of the telescope. The fan should be activated at the beginning
of the observation session to accelerate the temperature stabilization.
As soon as the optics have reached an equilibrium with the environment,
the fan should be turned off by unplugging the fan power cord. Fan operation
time should range between 5 and 25 minutes. While it is permissible to
run the fan continuously it is not recommended because the very slight
vibration of the fan may cause noticeable movement of the objects observed
in the sensitive optics.
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