Meade Comprehensive Guide to ETX Telescope Features and Operation
Page 14

Light 1 (top LED): The fastest speed. Use to move the telescope quickly from one point in the sky to another.

Light 2: Best for centering an object in the viewfinder.

Light 3: Best for centering an object in the field of a low-to-moderate power eyepiece, such as the standard SP 26mm.

Light 4: The slowest speed. Use to center an object in the field of view of high-power eyepieces, such as the optional 6.7mm or 12.4mm.

The four available speeds are:

Light 1

=

1200 x sidereal

(300 arc-min/sec or 5°/sec)

Light 2

=

180 x sidereal

(45 arc-min/sec or 0.75°/sec)

Light 3

=

32 x sidereal

(8 arc-min/sec or 0.13°/sec)

Light 4

=

8 x sidereal

(2 arc-min/sec or 0.034°/sec)

The two slowest speeds (8x and 32x sidereal) can be used for pushbutton (manual) tracking of astronomical objects while observing through the eyepiece.

Modes of Operation

The Electronic Controller can be set to operate in either of two primary modes: the Alt/Az mode (used when the telescope is operated in the altazimuth configuration; see below) and the polar mode (used when the telescope is polar- (or equatorial) aligned; see page 16).

•Choose the Alt/Az (altitude-azimuth, or vertical-horizontal) mode for all terrestrial operations of the telescope. In the Alt/Az mode, use the Arrow keys to slew the telescope to terrestrial or astronomical objects and, once you locate them, follow these objects if they move. However, in this mode astronomical tracking is not automatic and requires continuous pushes of the Arrow keys. The Electronic Controller is factory pre-set to the Alt/Az mode.

•Choose the polar mode when the telescope is equipped with either the optional #880 (ETX–90EC) or #881 (ETX-105EC or ETX-125EC) Table Tripod, or #883 Deluxe Field Tripod, for extensive astronomical observations. In this mode use the Arrow keys to slew the telescope to objects. In addition, the telescope’s internal motor drive is turned on, enabling the telescope to automatically track celestial objects.

You can configure the two screws on the bottom rear of the Electronic Controller handbox to change the default mode of the Electronic Controller to Alt/Az or polar. When in polar mode, you may also set the alignment to the hemisphere in which you are located (not necessary in the Alt-Az mode).

Caution: Mode screws A and B are the outer screws in the recess directly under the letters A and B on the rear of the Electronic Controller. Do not remove either of the inner two screws in the recess.

•Remove mode screw A (1, Fig. 12) to make the Northern hemisphere polar mode the automatic default of the Electronic Controller when power is applied (i.e., the motor drive is activated for operation in the Earth’s Northern Hemisphere).

•Remove mode screw B (2, Fig. 12) to make the Southern Hemisphere polar mode the automatic default of the Electronic Controller when power is applied (i.e., the motor drive is activated for operation in the Earth’s Southern Hemisphere ).

•Leave both the A and B screws in place (or remove both screws) to keep the telescope in the original factory default Alt/Az mode.

Note: Removing either A or B screw affects only the telescope’s default mode; you may still make mode changes when desired using the MODE key (see, APPENDIX A, page 26).

Telescope Mountings

A mount allows a telescope to move on its axes. The two basic types of mounting are Altazimuth (Alt/Az) and Polar (Equatorial).

Alt/Az Mode

Altazimuth (Alt/Az) mounting permits movement of the telescope tube in vertical (altitude) and horizontal (azimuth) directions. The ETX models incorporate an altazimuth mount (as shown in Fig. 9), ideal for terrestrial

 

Meade Instruments Corporation

 

 

FC

35-4702-00

CC

 

 

 

Tested to comply

 

 

 

with FCC Standards

 

A

FOR HOME OR OFFICE USE

B

 

 

 

1

 

 

 

2

Fig. 12: Mode screws on rear of Electronic Controller.

(1) Mode screw A; (2) Mode screw B.

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Contents Meade Instruments Corporation Page Contents QUICK-START Guide Slew SpeedTelescope and Electronic Controller Functions ETX-90EC Astro TelescopeViewfinder ETX Your Personal Window to the UniverseTelescope Controls Flip mirror control in the up position Computer Control PanelLight Blinking Off Indicator Light KeyElectronic Controller Functions Getting Started Aligning the Viewfinder Using The ViewfinderFocusing the Viewfinder ETX-90EC 8 x 21mm Erect-Image Viewfinder Alignment Observation Techniques Choosing an Eyepiece Understanding Magnification Telescope Focal Length Power = Eyepiece Focal Length1900mm Power = = 26mm Terrestrial ObservingElectronic Controller Astronomical ObservingSidereal Rate Slew SpeedsTelescope Mountings Alt/Az ModeModes of Operation You use Polar or Equatorial mounting. By Polar ModeTo move the telescope using the Electronic Controller Locating the Celestial Pole Polar Alignment ProcedureCelestial Coordinates Standard Tripod Leg ETX-105EC, ETX-125EC Standard Tripod Leg ETX-90ECHigh-Latitude Tripod Leg ETX-90EC High-Latitude Tripod Leg ETX-105EC, ETX-125ECPhotography ETX-90ECExample of a format 1 photo Few Tips on PhotographyPower 2x Barlow Optional AccessoriesPower ETX-105EC ETX-125EC Eyepiece#825 Right- Angle Viewfinder General Maintenance Storage and TransportTroubleshooting Inspecting the OpticsMeade Customer Service Telescope moves off a terrestrial object while observingSpecifications ETX-125EC Astro Telescope Specifications ETX-90EC Astro TelescopeSpecifications ETX-105EC Astro Telescope Tracking Motor Speeds Changing Modes Using the Electronic ControllerAppendix a Advanced Electronic Controller Functions Northern Hemisphere PolarAppendix B Helpful Charts Appendix C Precise Polar Alignment Setting Circles Setting CirclesMoon Appendix D YOU and the UniverseAutostar Glossary PlanetsDeep-Sky Objects Pleiades is one of the most beautiful open clustersMeade Limited Warranty Meade Instruments Corporation
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