www.meade.com/catalog/etx/etx_mak.html
ETX-90AT, ETX-105AT, and ETX-125AT Astro Telescopes ETX-90AT, ETX-105AT, and ETX-125AT When the original ETX^ telescope was introduced in 1996, it quickly crea ted a revolution in amateur astronomy. Here for the first time was a stu nningly beautiful, ultraportable, and highly versatile telescope system of unprecedented optical resolution and performance. Within one year of its introduction the ETX became the largest-selling modern telescope in the world.
Autostar Compu ter Controller ever produced in their price range. And yet without sac rificing any of the user-friendly features that started the ETX revoluti on. Optical Systems: Manufactured at the Meade Irvine, California, facility, ETX Maksutov-Cassegrain telescopes produce superlative, diffraction-limi ted optical performance and resolution. Optics so high in contrast, imag e brightness, and resolution that ETX-90AT, ETX-105AT, and ETX-125AT mod els often outperform many telescopes of larger apertures. ETX-90AT Maksutov-Cassegrain Optical System Fork Mounts with Standard-Equipment Dual-Axis Drive System and #497 Autos tar Controller: The rigid fork mountings of ETX Maksutov-Cassegrain mode ls include high-torque DC motors on both telescope axes, permitting elec tronic operation from the standard-equipment Autostar controller. With t he telescope placed in the altazimuth mode on a table, astronomical obje ct-tracking may be accomplished automatically, after a quick and easy 2- minute alignment of Autostar to the sky. Alternately, the telescope may be mounted in either the altazimuth or equatorial modes on the standard- equipment #884 Deluxe Field Tripod. Cordless Field Operation: The drive base of each telescope accepts eight (user-supplied) AA-batteries that power the telescope for about 20 hours of normal usage, negating any requirement for an external power source in the field.
Materials and Coatings: ETX optical systems include a Maksutov meniscus c orrector lens of Grade-A BK7 optical glass. This lens is individually ha nd-figured by a Meade master optician to achieve an optical null in comb ination with the Pyrex^ primary mirror. High transmission magnesium flu oride (MgF2) coatings on both sides of the correcting lens, as well as a luminum/silicon monoxide coatings on the primary and secondary mirrors, are provided as standard equipment. Optional coatings, described below, increase light transmission and reflectance still further.
Ultra-High Transmission Coatings (UHTC): Available optionally with the ETX-90AT, ETX-105AT, or ETX-125AT, the Meade UHTC group permits the hig hest levels of light transmission (about a 15% increase in total telesco pe light transmission compared to the standard coatings) ever offered on amateur telescopes. The UHTC group, if desired, must be specified at th e time of telescope order.
we sent the scope to a series of targets sprea d across the sky. Views of the Moon and planets were all satisfyingly crisp . One of my most enjoyable moments with this Mak came while I was viewing Castor on a foggy evening that offered very goo d seeing. The scope split this unequal double star very cleanly and disp layed the sort of Airy disks and diffraction rings that one sees in opti cal textbooks but seldom in real life." Standard Equipment: Meade ETX Astro Telescopes are supplied as complete i nstruments. Standard equipment includes a premium-grade Meade Series 400 0 Super Plssl 26mm eyepiece for 48X with the ETX-90AT, 57X with the ETX -105AT, or 73X with the ETX-125AT. The 8 x 21mm viewfinder of the ETX-90 AT incorporates an internal roof prism that results in an erect-image or ientation, facilitating the quick location and field-centering of both t errestrial and astronomical objects. ETX-105AT and ETX-125AT models are supplied with an 8 x 25mm right-angle viewfinder for comfortable object- sighting with the larger instruments. The #884 Deluxe Field Tripod is in cluded for rigid mounting of the telescope during standing or seated obs erving in either the altazimuth or equatorial mode. Use the standard-equ ipment #497 Autostar controller for automatic GO TO object locating. Motor Drive Systems DC servo motors with encoders, both axes;
At 50X the image showed incredible contrast and sharpness alon g the terminator. At 190X the lunar image fully maintained its rock-hard focus. Even at 350X, one hundred p ower per inch of aperture, no breakdown of the image occurred. Now I had to give the ETX the most sensitive test of all, viewing a second magnit ude star at this same extreme power. Clearly defined, faint, concentric diffraction rings surrounded the small, bright Airy disc. Taking the star both in and out of focus r evealed identically sized secondary shadow obstructions. Clearly, I was observing through an optical system that has no detectable wavefront err or."
Fifteen optionally available eyepieces permit ma gnification ranges of from 31X to over 300X with the ETX-90AT, from 37X to over #932 45 degree Erecting Prism For terrestrial observing with the ETX-90AT, ETX-105AT, and ETX-125AT Ast ro Telescopes the #932 45 Erecting Prism attaches to the telescope's re ar cell and presents correctly-oriented images, viewed at a convenient 4 57deg; Also shown in this photo are the Declination lock, focuser knob, and flip-mirror knob. The #126 2x Barlow Lens, a special short-foc us Barlow ideally suited to ETX systems, doubles the power of any eyepie ce. For terrestrial photography or astrophotography of the Moon and plan ets, the #64 T-Adapter threads to the telescope's rear cell and, with th e appropriate T-mount, accepts any 35mm camera with removable lens. In this way ETX models may be used for terrestrial photography or fo r astrophotography of the Moon and planets. Even the most novice observer will find himself or herself locating dozens of fascinating celestial objects the very first night out - from commonly-observed objects such as the rings of Saturn, the satellites of Jupiter, and the Orion Nebula (M42); to more difficult objects such as the Ring Nebula (M57) in Lyra, the Spiral Galaxy (M33) in Triangulum, an d the Sombrero Galaxy (M104) in Virgo; to very obscure objects near the telescope's threshold of visibility such as the diffuse nebula NGC 6559 in Sagittarius, the galactic star cluster NGC 1778 in Auriga, and the sp iral galaxy NGC 3310 in Ursa Major. Any of Autostar's database objects can be called up and entered on the ha nd controller display in seconds. The observer then simply presses the G O TO pushbutton and watches as the telescope automatically slews (moves) to the object and places it in the field of view. The effect of Autosta r is to bring objects easily within reach which were previously unreacha ble for all but the most dedicated of amateur astronomers. Without exaggeration the Meade Autostar Computer Controller opens up a ne w era in astronomical study for the casual or beginning astronomer, just as Meade LX200 and LX200GPS Schmidt-Cassegrains have for the advanced a mateur. Most Autostar users see more celestial objects in one night's vi ewing than typical first-time telescope owners previously have in a life time. Object Database: Included within Autostar's database are all of the follo wing astronomical objects a range of objects certain to keep even the most active amateur astronomer growing in his or her studies of the skie s for years: 5,386 objects from the Index Catalog (IC); the complete Index Catalog 7,840 objects from the New General Catalog (NGC); additional galaxies, ne bulae, and star clusters of all types; the complete New General Catalog 109 objects from the Caldwell Catalog of the best objects for small teles copes 110 Messier objects; the complete Messier catalog 16,800 stars from the Smithsonian Astrophysical Observatory (SAO) catalog , including double stars, variable stars, and other stars of special not e 50 Earth-orbiting satellites 26 asteroids, including all of the brightest asteroids 15 periodic comets 8 major planets from Mercury to Pluto Any of the objects in the preceding listing can be located simply by call ing up the object from the Autostar database and pressing GO TO. Within seconds Autostar directs the...
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