Astro-Tech AT 106 Quick Start Manual

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A T 106
Thank you for choosing this Astro-Tech AT106 high-
performance apochromatic ED triplet refractor.
A review in Sky & Telescope magazine said the AT106
"provided superb optical and mechanical quality" and called it
"an amazing bargain in the world of premium refractors."
Astro-Tech AT 106 Apochromatic ED Triplet Refractor Specifications
Aperture .......................................... 106mm (4.17")
Focal Length ...............................................690mm
Focal Ratio ...................................................... f/6.5
Objective Type ........... collimatable air-spaced triplet
using all Ohara glass, including an FPL-53 ED element
Optical Coatings ........................... fully multicoated
Resolving Power
(Dawes' Limit)
Visual Limiting Magnitude .............. 12.6 maximum
Light Grasp
(versus the eye)
Field Stops .......................... three knife-edge baffles
Focuser ............................. 2.7" dual-speed Crayford
with 10:1 reduction ratio fine focus; 2" and 1.25"
compression ring accessory holders; 360° rotating
focuser with separate 360° camera angle rotation
Focuser Travel ............ 80mm (3.15") with mm scale
Back Focus
(drawtube fully extended)
PARTS OF THE AT106
Lock knob for 360°
2" accessory
holder camera angle rotation
lock knob
Lock knob for focuser
Right coarse
Fine focus
focus knob
knob
Brass compression ring
Dust cover
Your Astro-Tech AT106 refractor is usable for day and night
viewing, simply by adding a star diagonal, eyepiece, and mount. Any
1.25" or 2" eyepiece can be used, from a 40mm for the lowest practical
magnification (17x) to a 3.2mm (215x) for high power use. A 2"
compression ring accessory holder on the focuser and a separate
1.25" compression ring accessory holder let you use either 1.25" or
2" star diagonals and eyepieces with no other adapter needed.
Mounting your AT106: A stable altazimuth or astronomical mount
is essential for best viewing with the 11 pound AT106. Your scope is
not supplied with mounting rings, but 114mm i. d. split rings and a
variety of dovetail plates are readily available from your Astro-Tech
dealer for installing your AT106 on the mount of your choice.
....... 1.09 arc seconds
.............................. 229x
..... 65mm (2.25")
Retractable
dew shield
Lock knob for 360°
focuser rotation
drawtube
Lock knob for
dew shield
(under tube)
1.25" accessory
lock knob
from Astronomy Technologies
This instruction sheet will help you get the most out of your
new refractor so you can enjoy a lifetime of high-performance
observing and imaging.
Please familiarize yourself with your telescope's parts and
functions before using it for the first time.
Finder ...... none; mounting point provided for optional
Astro-Tech multiple reticle finder or similar finder
Dew Shield ...................... retractable, with lock knob
Dew Shield Diameter ......................... 148mm o. d.
Objective Lens Cover ......................... slip-on metal
Tube Diameter .................................... 114mm o. d.
Tube Length
(lens shade retracted)
Tube Length
(lens shade extended)
Optical Tube Weight .......................... 11 lbs. (5 kg)
Case ....... 9.5 lb. (4.3 kg) aluminum-frame foam-fitted
lockable hard case, with carrying handle
Case Dimensions ..................... 28.25" x 9.25" x 10"
Lowest Usable Power ............ 17x (40mm eyepiece)
Highest Terrestrial Power ....... 98x (7mm eyepiece)
Highest Practical Power ........ 172x (4mm eyepiece)
Theoretical Maximum ........ 215x (3.2mm eyepiece)
Lock knob for
focuser drawtube
Mounting point for
optional finder
Focusing
scale on
focuser
drawtube
Left coarse
focus knob
Lock knob for 360°
rotatable camera
angle adjuster
2" accessory
holder
1.25"
accessory
holder
Astronomical observing: The theoretical maximum usable power
available from your AT106 is 215x, although this requires a 3.2mm
eyepiece that provides a very narrow and dim 0.49mm diameter exit
pupil. Still higher powers are within your scope's capabilities, but
require truly excellent seeing conditions and the patience to wait for
those conditions to make their brief and infrequent appearances.
A more practical maximum magnification for astronomical viewing
with your AT106 would be 172x, using a 4mm eyepiece.
Keep in mind that seeing conditions play an important role in how
high a magnification you can use on any given night. Only very good
seeing conditions (clear skies and calm air) will support viewing at
215x. Under less than ideal conditions, powers in the 115x to 140x
......... 24" (610mm)
......27.5" (698mm)
1 of 3
focuser
mounting
screws
(Do not
adjust)
Fine
focus
knob
Right
coarse
focus
Brass
knob
compression
ring
2" accessory
holder lock knob