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6

place. The tips of the tensioner and nylon screws should seat
into the wide groove on the rear of the finder scope’s body.

Slide the base of the finder scope bracket into the dovetail
holder near the focuser. Lock the bracket into position by tight-
ening the knurled thumbscrew on the dovetail holder.

Installing the CorrecTension (XT) Friction
Optimization System

Perhaps the most exciting new feature of the SkyQuest
Dobsonians is the CorrecTension Friction Optimization sys-
tem. Because of their light weight, 6" and 8" Dobsonians have
always been plagued by insufficient friction on the altitude
bearing surfaces. As a result, such telescopes move up and
down much too freely. This causes problems when the observ-
er tries to accurately center and track an object for viewing,
especially at higher powers. Also, the telescope becomes very
sensitive to balance, requiring additional equipment such as
counterweight systems or adjustable side bearings to com-
pensate.

SkyQuest Dobsonians employ a simple yet effective remedy
for the friction problem that obviates the need for such cum-
bersome countermeasures. CorrecTension Friction Optimization
utilizes a spring coil to “pull” the tube assembly down onto the
altitude bearing pads, thereby increasing the friction by just
the right amount. With CorrecTension, you can change eye-
pieces, or add a barlow lens or solar filter without having to
tediously adjust the telescope’s balance as you would with
other Dobsonians. The altitude friction will roughly equal the
azimuth friction, ensuring optimal performance.

To install the CorrecTension assembly, follow these steps
while referring to Figure 7:

1. Put one of the black nylon spacers on a black Phillips-head

screw. The spacer should be oriented so the narrow end
seats against the head of the screw. Slip one of the black
1/4" washers over the end of the screw. Now, thread the
screw into the hole in the base side panel just below the
cradle. The screw will thread into the preinstalled insert in

the hole. Use a Phillips screwdriver to tighten the screw.
Repeat this procedure on the opposite side panel.

2. Next, insert one of the screws with a round plastic knob

attached through the end ring of one of the springs. Slip a
black nylon spacer onto the screw. Orient the spacer so
the narrow end is closest to the knob. Thread the entire
assembly into the hole in the center of the telescope’s alti-
tude side bearing until tight. The end ring of the spring
should seat onto the narrow end of the spacer. Repeat this
procedure for the other altitude side bearing.

3

Attach a pull loop to the free end of each spring. Slide the
loop through the opening in the ring on the end of the spring.

4. Now, pull each spring down using the pull loop, and posi-

tion the spring’s end ring over the head of the Phillips
screw (installed in Step 1) and onto the narrow part of the
nylon spacer, as shown in Figure 8. You needn’t attach
both springs simultaneously; one at a time is fine.

Figure 7. 

Close-up view of the CorrecTension system, which

pulls the tube assembly down onto the altitude bearing pads.

Black nylon

spacers

1/4" washer

(black)

Altitude side bearing

Screw w/round knob

Spring

Phillips-head 
screw (black)

Pull loop

Figure 8. 

(a)

To attach the spring to the base, grip the pull loop

with your index finger and pull down on the spring.

(b)

While pulling

down, slip the end ring of the spring over the bolt head and onto the
narrow part of the nylon spacer, then release the pull loop.

a.

b.

Summary of Contents for SkyQuest XT6 9806

Page 1: ...ding Exceptional Consumer Optical Products Since 1975 Customer Support 800 676 1343 E mail support telescope com Corporate Offices 831 763 7000 P O Box 1815 Santa Cruz CA 95061 Orion SkyQuest XT6 XT8 9806 and 9808 Dobsonian Reflecting Telescopes ...

Page 2: ...anel Front brace Handle Top baseplate Ground baseplate 2 Figure 1 The SkyQuest XT Dobsonian XT6 pictured Finder scope Finder scope bracket Eyepiece Focus knob Optical tube Altitude side bearing CorrecTension Friction Optimization System Pull loop Left side panel Eyepiece rack ...

Page 3: ...ontaining the unassembled Dobsonian base Be careful unpacking the boxes We recommend keeping the original shipping contain ers In the event that the telescope needs to be shipped to another location or returned to Orion for warranty repair hav ing the proper shipping containers will help ensure that your telescope will survive the journey intact Make sure all the parts in the Parts List below are ...

Page 4: ...ing should be flush with the top surface of the top baseplate 6 Insert the T nut K into the center hole of the ground base plate A so the nut s flanged top is on the same side of the baseplate as the Teflon pads Thread the large hex head bolt G with a 3 8 washer F attached up through the ground baseplate and through the T nut until it is tight Now position the top baseplate D with side panels atta...

Page 5: ... the tube will not yet be properly bal anced since the eyepiece and finder scope are not in place and the CorrecTension system has not been installed Installing the Finder Scope The SkyQuest XT6 8 come with a high quality 6x30 achro matic finder scope Figure 6a The 6 means it magnifies 6 times the 30 means it has a 30mm diameter lens To place the finder scope in the finder scope bracket first unth...

Page 6: ...g to Figure 7 1 Put one of the black nylon spacers on a black Phillips head screw The spacer should be oriented so the narrow end seats against the head of the screw Slip one of the black 1 4 washers over the end of the screw Now thread the screw into the hole in the base side panel just below the cradle The screw will thread into the preinstalled insert in the hole Use a Phillips screwdriver to t...

Page 7: ...the two thumbscrews on the eyepiece holder and insert one of the eyepieces Then secure it in place with the thumbscrews The other eyepiece can be placed in the eyepiece rack until it is needed For the XT8 There are three thumbscrews on the focuser one holds the eyepiece and two hold the 1 25 adapter To insert the eyepiece loosen the thumbscrew that is on the 1 25 adapter itself it will be highest ...

Page 8: ...ve lens cell in or out on the finder scope body Precise focusing will be achieved by focusing the finder scope on a bright star Once the image appears sharp retighten the lock ring behind the objective lens cell The finder scope s focus should not need to be adjusted again Aiming Pointing the Telescope Now that the finder scope is aligned the telescope can be quickly and accurately pointed at anyt...

Page 9: ...pect the user to compensate for heavier accessories by adding weight to the opposite end of the telescope tube Such counterweighting systems can be expensive and unwieldy The CorrecTension Friction Optimization system of the SkyQuest Dobsonians however solves the finicky balance problem The spring coils pull the tube down onto the base thereby increasing the friction on the altitude bearing pads W...

Page 10: ...Now the base and tube are disengaged and can be transported separately Do not use the navigation knob as a carry handle Note The SkyQuest may be too heavy for some users to lift and carry as one unit Do not strain yourself If the load seems too heavy disengage the springs and carry the base and tube separately When putting the SkyQuest into a vehicle common sense pre vails It is especially importa...

Page 11: ...t setscrews while tightening the other two as depicted in Figure 14 The goal is to center the primary mirror reflection in the secondary mirror as in Figure 12d Don t worry that the reflection of the secondary mirror the smallest circle with the collimation cap dot in the center is off center You will fix that in the next step Adjusting the Primary Mirror The final adjustment is made to the primar...

Page 12: ... air currents rising from them which distort the image seen in the eyepiece Similarly you should not observe through an open window from indoors Better yet choose a site out of town away from any light pollution You ll be stunned at how many more stars you ll see Most importantly make sure that any chosen site has a clear view of a large portion of the sky Cooling the Telescope All optical instrum...

Page 13: ...poil your night vision Tracking Celestial Objects The Earth is constantly rotating about its polar axis complet ing one full rotation every 24 hours this is what defines a day We do not feel the Earth rotating but we can tell that it is at night by seeing the apparent movement of stars from east to west This movement translates into a rate of approxi mately 25 per minute or 15 arc seconds per seco...

Page 14: ...ivity in the Sun Many observers like to make drawings of sunspots to monitor how the Sun is changing from day to day Important Note Do not look at the Sun with any optical instrument without a professionally made solar filter or permanent eye damage could result Also be sure to cover the finder scope or better yet remove it altogether C The Planets The planets don t stay put like the stars so to f...

Page 15: ...t recognize the constella tion on sight consult a planisphere The planisphere gives an all sky view and shows which constellations are visible on a given night at a given time Now look at your star chart and find the brightest star in the constellation that is near the object that you are trying to find Using the finder scope point the telescope at this star and center it on the crosshairs Next lo...

Page 16: ...secondary mirror of your telescope are front surface aluminized and overcoated with hard silicon dioxide which prevents the aluminum from oxidizing These coatings normally last through many years of use before requiring re coating which is easily done To clean the secondary mirror it must be removed from the telescope Do this by holding the secondary mirror holder sta tionary with your fingers don...

Page 17: ... secondary mirror 34 5mm Weight 38 lbs 6 oz Tube length 45 5 Tube outer diameter 7 25 SkyQuest XT 8 Primary mirror focal Length 1200mm Primary mirror diameter 203mm Focal Ratio f 5 9 Focuser Rack and pinion Accepts 2 eyepieces and 1 25 eyepieces with adapter Eyepieces 25mm 10mm Sirius Plössl fully coated with multi coatings 1 25 barrel diameter Magnification with supplied eyepieces 48x 120x Finder...

Page 18: ... Way Watsonville CA 95076 If the product is not registered proof of purchase such as a copy of the original invoice is required This warranty does not apply if in Orion s judgment the instrument has been abused mishan dled or modified nor does it apply to normal wear and tear This warranty gives you specific legal rights and you may also have other rights which vary from state to state For further...

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