Meade Instruments ETX 90AT - Manual (Page 49)

49
Bearings:
Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ball bearings
Azimuth . . . . PTFE thrust bearing and radial ball bearing
Materials:
Tube body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . aluminum
Mounting . . . . . . ABS, with internal aluminum structure
Primary mirror. . . . . . . . . . . . . . . . . . . . . . . . Pyrex
® glass
Correcting lens . . . . . . . . . . . BK7 optical glass, Grade-A
Telescope dimensions:
. . . . . . . . . . . . . 43cm x 25cm x 20cm (17” x 10” x 8”)
Telescope net weight:
(incl. Autostar & batteries) . . . . . . . . . . . 6.1kg (13.5 lbs)
Telescope shipping weight. . . . . . . . . . . . . . . . 8.3kg (18.4 lbs)
Battery Life (approx.):
with Autostar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 hrs
Specifications: ETX-125AT Astro Telescope
Optical design . . . . . . . . . . . . . . . . . . . . Maksutov-Cassegrain
Primary mirror diameter . . . . . . . . . . . . . . . . . . 138mm (5.43”)
Clear aperture . . . . . . . . . . . . . . . . . . . . . . . . . . . 127mm (5.0”)
Focal length . . . . . . . . . . . . . . . . . . . . . . . . . . 1900mm (74.8”)
Focal ratio (photographic speed) . . . . . . . . . . . . . . . . . . . . f/15
Near focus (approx) . . . . . . . . . . . . . . . . . . . . . . . . 4.6m (15 ft)
Resolving power . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 arc secs
Super multi-coatings (EMC) . . . . . . . . . . . . . . . . . . . . standard
Limiting visual stellar magnitude (approx.) . . . . . . . . . . . . 12.5
Image scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.76°/inch
Maximum practical visual power . . . . . . . . . . . . . . . . . . . 500X
Optical tube dimensions
(dia. x length) . . . . . . . . . . 14.6cm x 36cm (5.75” x 14.2”)
Viewfinder . . . . . . . . . . . . . . . . . . . . . . . . 8 x 25mm right-angle
Secondary mirror obstruction (dia.; %) . . 39.4mm (1.6”); 9.6%
Telescope mounting . . . . . . . . . . . . . . . . fork type; double tine
Setting circle diameters . . . . . . . . . . . . . . . Dec.: 4.3”; R.A.: 9”
Input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 volts DC
Motor Drive System . . . DC servo motors with encoders, both axes
Bearings:
Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ball bearings
Azimuth . . . . . . . . . . . . . . . . . . . . . . . . . . . . ball bearings
Materials:
Tube body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . aluminum
Mounting . . . . . . . ABS, with internal aluminum structure
Primary mirror. . . . . . . . . . . . . . . . . . . . . . . . Pyrex
® glass
Correcting lens . . . . . . . . . . . BK7 optical glass, Grade-A
Telescope dimensions:
. . . . . . . . . . 48cm x 23cm x 27cm (19” x 8.9” x 10.8”)
Telescope net weight:
(incl. Autostar & batteries) . . . . . . . . . . . 6.9kg (15.2 lbs)
Telescope shipping weight. . . . . . . . . . . . . . . 11.4kg (25.2 lbs)
Battery Life (approx.):
with Autostar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 hrs