Astro-Tech AT6RC Quick Start Manual

astro-tech
A T 6 RC
Thank you for choosing this Astro-Tech AT6RC
6" f/9 Ritchey-Chrétien reflector, selected as a Sky
& Telescope Hot Product for 2009.
Your AT6RC is designed primarily for exceptional
coma-free imaging using webcams, Deep Sky
Imager-type cameras, and DSLRs.
Visual observing is also possible with your AT6RC,
however. The scope's 2" Crayford focuser will accept
PARTS OF THE AT6RC
Fine
focus
Lock knob for focuser drawtube; a
knob
drawtube tension knob is hidden
behind the coarse focus knob
Right coarse
focus knob
thread-on extension
tubes
Astro-Tech AT 6RC Ritchey-Chrétien Reflector Specifications
Aperture .................................................... 152mm (6")
Focal Length .................................................. 1370mm
Focal Ratio ............................................................... f/9
Optical Type .............................. dual hyperbolic mirror
Mirrors .......................... BK7 optical glass, coated with
enhanced aluminum and overcoated with quartz
Secondary Mirror Holder Obstruction ............. 76mm
Field Stops ................. eight internal knife-edge baffles
Tube Diameter ................................. 7.5" (190mm) o. d.
Tube Length
(no extensions)
Your Astro-Tech AT6RC 6" f/9 true Ritchey-Chrétien reflector is
designed primarily for exceptional astronomical imaging, to provide
you with the coma-free photographic field astrophotographers crave,
but can't get from conventional reflectors and Schmidt-Cassegrains.
Visual observing is also possible, although with somewhat reduced
contrast compared to conventional reflectors. There is a 2" compres-
sion ring accessory holder on the focuser drawtube, plus a separate
1.25" compression ring accessory holder, so you can use either 1.25"
or 2" star diagonals and eyepieces with no other adapter needed.
Mounting shoe for optional finder
Locking collar for 360° rotatable focuser
true Ritchey-Chrétien reflector
(50% by diameter, 25% by area)
................. 19.6" (498mm)
from Astronomy Technologies
both 1.25" and 2" star diagonals.
This instruction sheet will provide you with
information on how to get the most out of your
new Ritchey-Chrétien reflector, and how to properly
maintain your telescope so it can give you a lifetime
of observing and imaging enjoyment.
Please familiarize yourself with your scope's parts
and functions before operating it for the first time.
Vixen-style equatorial
mount dovetail
Left coarse
focus knob
1.25" accessory
lock knob
1.25" accessory
Tube Length
(all 3 extensions)
Tube Weight
(no extensions)
Tube Weight
(all 3 extensions)
Mounting System ...... 12.75" long Vixen-style dovetail
Focuser ....................................... dual-speed Crayford
2" and 1.25" compression ring accessory holders;
360° rotating camera angle/observing angle adjuster
Focuser Travel .......... 1.34" (34mm) with dual inch and
millimeter scales on drawtube for repeatable focus
Finder ........ none; mounting shoe provided for optional
Astro-Tech multiple reticle finder or similar finder
Components of the Focusing System: To minimize drawtube
flexure under heavy loads during imaging, the drawtube travel of the
external focuser is kept short, at 34mm. To make up for the longer
all-purpose focuser drawtube travel found in refractors used for im-
aging (typically 80mm to 135mm), the focusing system has four com-
ponents, as shown in the illustration on the next page. They include
a Crayford focuser that can be rotated 360° and is threaded onto the
scope's rear cell when you receive your AT6RC, and three 3.7" diam-
eter extension tubes (two 1" long and one 2" long) that can be threaded
Dust cap
2" accessory
adapter lock knob
............... 23.6" (600mm)
............... 12.1 lbs. (5.5 kg)
........ 12.85 lbs. (5.84 kg)
with 10:1 reduction ratio fine focus;
Focusing
scales on
focuser
drawtube
Fine
focus
knob
Right
coarse
focus
knob