Meade Instruments Corporation
Telescopes · Binoculars · Microscopes
 
Meade LX50 Schmidt-Cassegrain Instruction Manual
D. THE LX50 KEYPAD HAND CONTROLLER
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.
The LX50 Hand Controller is a dual-axis drive corrector with 4 photo-guide or microslew speeds, and allows the very small tracking corrections necessary for long exposure astrophotography as well as the microslewing to and centering of objects. This hand controller is also used to access the special functions of the LX50 telescope such as reversing the button directions and selecting different drive rates.

[ toc ]1. LX50 Self Diagnostic Test

When the LX50 is first powered up, all LED's are turned on in rotation four times, indicating the telescope is performing the self diagnostic tests. The circuits and logic are tested and if any faults are found, the LED's will continue to circulate.

Table 1: Keypad Functions

[ toc ]2. LX50 Hand Controller Normal Operation

a. Direction Keys

Labeled N, S, E, and W (1, Fig.18) these four keys make the LX50 move, or microslew in a specific direction, with an option of four different speeds, explained below. When pressing a direction key, the only feedback is the motion of the telescope.

b. Speed Key

This key is used to change the speed at which the telescope is moved when pressing one of the direction keys. The currently selected speed is indicated by the speed indicator illuminated LED beside the speed key, and pressing the speed key will increment the selected speed to the next speed.

The four speeds are 32x sidereal rate which is useful for centering the object in a viewfinder, 16x sidereal rate for centering the object in a wide-field eyepiece, 8x sidereal rate for centering the object in a high-power eyepiece, and 2x sidereal rate which is used for guiding an astrophotograph.

NOTE: All of the slew speeds will drive the LX50 in all four directions, except for 2x. The 2x sidereal speed has one difference in that it will not interrupt the Right Ascension tracking direction to make Easterly (for Northern hemisphere) or Westerly (for Southern hemisphere) adjustments; it will merely stop. You will find, however, that the slower drive will move the image opposite of the tracking direction, without disturbing the smooth drive action. This performance is absolutely essential when making astrophotographs.

It should also be noted that the tracking speed of the telescope is VERY slow-one complete revolution in 24 hours. You will not SEE the telescope moving when it is tracking. You will also not see the telescope move when pressing a direction key at the 2x speed unless you are looking at an object through the eyepiece.

[ toc ]3. LX50 Hand Controller Special Function Menu

This feature is used to customize the operation of the LX50 telescope by changing up to four functions of the telescope.

To enter the Special Function Menu, simply hold down the East and West buttons for 2 seconds. The following chart summarizes these features.

To move between features, use the N and S keys.

To select or change a feature, use the Speed key.

To exit the Special Function Menu, press the N key until all four LED's blink in pairs and then hit the Speed key. This action will return the telescope to normal operation.

[ toc ]a. Northern/Southern Hemisphere Operation (32x LED)

The LX50 is design to be operated from both the Northern and Southern hemispheres. The default is the Northern hemisphere. It can be temporally changed from the hand controller, using the Special Function Menu. This change will be in effect as long as power is supplied to the telescope. Upon power-up, the hemisphere operation reverts back to the Northern hemisphere setting.

To change the hemisphere operation, use the N / S key to move to the 32x LED. Note: The LED will blink slowly to indicate Northern hemisphere operation or rapidly for Southern hemisphere operation. Pressing the Speed button will toggle between these hemisphere settings.

[ toc ]b. Reversing the N / S Button Direction

When guiding an astrophoto, it is often desirable to reverse the direction of the telescope in North and South movements (e.g., when you press the N button, the telescope will move South). To make this change, use the N / S key to move to the 16x LED. Press the Speed key. The 16x LED will now blink quickly indicating the buttons have been reversed.

[ toc ]c. Reversing the E / W Button Direction

When guiding an astrophoto, it is often desirable to reverse the direction of the telescope in East and West movements (e.g. when you press the W button, the telescope will move East). To make this change, use the N / S key to move to the 8x LED. Press the Speed key. The 8x LED will now blink quickly indicating the buttons have been reversed.

[ toc ]d. Changing the Tracking Rate

The tracking rate can be changed in .5% increments using this function. To change the rate, follow these steps:

1. Use the N / S key to move to the 2x LED.

2. Pressing the Speed key will activate this mode for input and turn off all four LED's.

3. Press the N key for each .5% speed increase (the 32x LED will blink once for each key press) or the S key for each .5% speed decrease (the 8x LED will blink once for each key press).

4. When the desired number of speed correction adjustments is entered, press the Speed key to complete the adjustment.

When the Speed key is pressed, the 32x or 8x LED will blink once for each .5% adjustment entered, confirming the number of adjustments, and then return to the Special Function Menu, with the 2x LED quickly blinking to indicate the tracking rate has been adjusted.

Note: Whenever tracking speed changes are requested, they are made relative to the standard speed - NOT relative to the last adjusted speed.

[ toc ]e. Exiting the Special Function Menu

To exit the Special Function Menu, press the N key until all four LED's blink in pairs and then hit the Speed key. This action will return the telescope to normal operation.

Figure 19: LX50 Power Panel

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