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Meade LX50 Schmidt-Cassegrain Instruction Manual
 C. TELESCOPE ASSEMBLY
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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