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Object appears in the viewfinder but not in the eyepiece:

 

 

The viewfinder is not properly aligned with the telescope (see 

THE VIEWFINDER

). 

Slew speed does not change when the SPEED key is pressed or the telescope moves slowly even though 
the fast slew speed is chosen:

 

 

Verify that only one light is lit on the Electronic Controller. If more than one light is on or blinking then the 
Mode function is active. Exit the Mode function by pressing and holding the MODE key until only one light is 
on (see

Electronic Controller Modes

). 

 

The battery power may be low (see 

Assembly Instructions

.) 

Telescope does not track a celestial object:

 

 

The telescope can only track celestial objects automatically if it is properly polar aligned and the motor drive 
has been activated (see 

Polar Alignment Procedure

 and 

Modes of Operation

). 

Images through the eyepiece appear unfocused or distorted:

 

 

The magnification used may be too high for the seeing conditions. Back off to a lower power eyepiece 
(see

Understanding Magnification

). 

 

If inside a warm house or building, move outside. Interior air conditions may distort terrestrial or celestial 
images, making it difficult, if not impossible, to obtain a sharp focus. For optimal viewing, use the telescope 
outside in the open air instead of observing through an open or closed window or screen. 

 

If viewing a land object on a warm day, heat waves will distort the image (see 

Terrestrial Observing

). 

 

For clear viewing of objects, turn the focus knob (9, Fig. 1) slowly since the "in-focus" point of a telescope is 
precise. Turning the focus knob too quickly may cause the focus point to pass without notice. 

 

The optics within the telescope need time to adjust to the outside ambient temperature to provide the 
sharpest image. To "cool down" the optics, set the telescope outside for 10 to 15 minutes before observing 
begins. 

Telescope moves off a terrestrial object while observing:

 

 

The motor drive may be activated (see 

Modes of Operation

). 

 

Verify that the vertical and horizontal locks are tight (see 

Telescope Controls

). 

Telescope does not move past a certain point:

 

 

The built-in vertical or horizontal rotational "stops" may have been reached (see 

Rotational Limits

). 

Telescope pauses when changing slew direction:

 

 

This pause is normal (see 

Arrow Keys

). 

A terrestrial object appears reversed left-for-right:

 

 

An eyepiece in the standard 90° observing position (4, Fig. 1) yields this image orientation. To view a 
correctly oriented image, the optional #932 Erecting Prism is required (see 

OPTIONAL ACCESSORIES

Meade Customer Service

 

 
If you have a question concerning the ETX-90EC, call the Meade Instruments Customer Service Department at 
(949) 451-1450, or fax at (949) 451-1460. Customer Service hours are 8:30 AM to 4:30 PM, Pacific Time, Monday 
through Friday. In the unlikely event that the ETX-90EC requires factory servicing or repairs, 

write or call the 

Содержание ETX-90EC

Страница 1: ...rsects the celestial sphere This point in the sky is located near the North Star Polaris In mapping the surface of the Earth lines of longitude are drawn between the North and South Poles Similarly li...

Страница 2: ...s telescope such as the ETX 90EC this motion is rapid indeed If the motor drive has not been engaged objects centered in the telescope s eyepiece move entirely out of the field of view in 30 to 160 se...

Страница 3: ...d horizontal locks 6 and 10 Fig 1 and rotate the telescope so that it is oriented as shown in Fig 15 Tighten the vertical and horizontal locks In this orientation the telescope s optical tube is lined...

Страница 4: ...ast for millions of years Maria plural for mare are smooth dark areas scattered across the lunar surface These dark areas are large ancient impact basins that were filled with lava from the interior o...

Страница 5: ...ETX 90EC Titan the largest of Saturn s 18 moons can also be seen as a bright star like object near the planet Deep Sky Objects Star charts can be used to locate constellations individual stars and de...

Страница 6: ...0 Format 2 1450mm focal length Camera Body T Mount Sections 1 and 2 of the 64 T Adapter see Fig 19 Format 2 utilizes both sections of the 64 T Adapter threaded together to form a rigid unit as shown i...

Страница 7: ...hould be acceptable If used for astrophotography the meter probably will not provide good results since camera meters are not made to compensate for a dark sky 5 Terrestrial photography through the ET...

Страница 8: ...ndard equipment with the ETX 90EC telescope Use these eyepieces only under extremely steady atmospheric conditions Fig 23 Optional eyepieces yield higher and lower magnifying powers with the telescope...

Страница 9: ...priate to your brand of 35mm camera With the 64 T Adapter and T Mount in place the camera body is rigidly coupled to the telescope s optical system which in effect becomes the camera s lens 880 Table...

Страница 10: ...ght side up but reversed left for right The 932 Prism threads on to the telescope s photo port 17 Fig 1 and presents a correctly oriented image as well as a convenient 45 observing angle An eyepiece o...

Страница 11: ...244 Electric Focuser The 1244 Focuser Fig 33 replaces the manual focuser knob of the ETX 90EC and permits smooth precise electric focusing of the image through a remote handbox supplied with the focus...

Страница 12: ...yet notwithstanding its precision and detail Epoch 2000sk is easy and intuitive to use even by the novice Epoch 2000sk operates the ETX 90EC through a laptop computer in the field using the 497 Autost...

Страница 13: ...turn of the telescope to the Meade factory 5 If the ETX 90EC is used outdoors on a humid night telescope surfaces may accumulate water condensation While such condensation does not normally cause any...

Страница 14: ...not come on or there is no response when pressing the Electronic Controller arrow keys Verify that the computer control panel power switch 1 Fig 4 is in the ON position Verify that the Electronic Cont...

Страница 15: ...ng a land object on a warm day heat waves will distort the image see Terrestrial Observing For clear viewing of objects turn the focus knob 9 Fig 1 slowly since the in focus point of a telescope is pr...

Страница 16: ...gs standard Limiting visual stellar magnitude approx 11 7 Image scale 1 16 inch Maximum practical visual power 325X Optical tube dimensions dia x length 10 4cm x 27 9cm 4 1 x 11 Secondary mirror obstr...

Страница 17: ...is recommended to purchase the 883 Deluxe Field Tripod The tripod head tilts easily to the local latitude angle for quick polar alignment and locks in a 90 position to facilitate Alt Az viewing see OP...

Страница 18: ...ally turn the R A circle 14 Fig 1 to read the R A of the object at the R A pointer 7 Fig 15 3 The R A circle is now calibrated to read the correct R A of any object at which the telescope is pointed T...

Страница 19: ...The Summer Triangle is a notable region in the sky to the left of the handle of the Big Dipper The triangle is made up of three very bright stars Vega Deneb and Altair By drawing an imaginary line ou...

Страница 20: ...ut 4 3 light years or 25 trillion miles This distance is so large that if a scale model were created with the Earth one inch away from the Sun the nearest star would have to be placed over 4 miles awa...

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