Celestron 21062, 31042 User manual

ENGLISH

AstroMaster Series Telescopes

INSTRUCTION MANUAL

● AstroMaster 70 EQ # 21062 ●AstroMaster 76 EQ # 31035 ● AstroMaster 114 EQ # 31042

Table of Contents
INTRODUCTION ..........................................................................................................................	3
ASSEMBLY ...................................................................................................................................	6
Setting up the Tripod ..................................................................................................................	6
Attaching the Equatorial Mount..................................................................................................	7
Installing the Counterweight Bar & Counterweights..................................................................	7
Attaching the Slow Motion Cables.............................................................................................	8
Attaching the Telescope Tube to the Mount...............................................................................	8
Installing the Diagonal & Eyepiece (refractor)...........................................................................	9
Installing the Eyepiece on the Newtonians.................................................................................	9
Moving the Telescope Manually ..............................................................................................	10
Balancing the Mount in R.A. ....................................................................................................	10
Balancing the Mount in Dec. ....................................................................................................	10
Adjusting the Equatorial Mount................................................................................................	11
Adjusting the Mount in Altitude...............................................................................................	11
TELESCOPE BASICS .................................................................................................................	12
Image Orientation .....................................................................................................................	13
Focusing....................................................................................................................................	13
Aligning the Finderscope..........................................................................................................	13
Calculating Magnification ........................................................................................................	14
Determining Field of View .......................................................................................................	15
General Observing Hints...........................................................................................................	15
ASTRONOMY BASICS ..............................................................................................................	16
The Celestial Coordinate System..............................................................................................	16
Motion of the Stars....................................................................................................................	16
Polar Alignment with Latitude Scale........................................................................................	17
Pointing at Polaris.....................................................................................................................	18
Finding the North Celestial Pole...............................................................................................	18
Polar Alignment in the Southern Hemisphere ..........................................................................	19
Aligning the Setting Circles......................................................................................................	21
Motor Drive ..............................................................................................................................	22
CELESTIAL OBSERVING .........................................................................................................	23
Observing the Moon .................................................................................................................	23
Observing the Planets ...............................................................................................................	23
Observing the Sun.....................................................................................................................	23
Observing Deep-Sky Objects....................................................................................................	24
Seeing Conditions .....................................................................................................................	24
ASTROPHOTOGRAPHY............................................................................................................	25
Short Exposure Prime Focus Photography ...............................................................................	25
Piggyback Photography ............................................................................................................	25
Planetary & Lunar Photography with Special Imagers.............................................................	25
CCD Imaging for Deep Sky Objects ........................................................................................	25
Terrestrial Photography ............................................................................................................	25
TELESCOPE MAINTENANCE..................................................................................................	26
Care and Cleaning of the Optics ...............................................................................................	26
Collimation of a Newtonian......................................................................................................	26
OPTIONAL ACCESSORIES.....................................................................................................	29
AstroMaster Specifications...........................................................................................................	30

Congratulations on your purchase of an AstroMaster Series telescope. The AstroMaster Series of telescopes come in several different models and this manual covers three models mounted on the CG-2 German Equatorial Mount ---

70mm refractor, 76mm Newtonian, and 114mm Newtonian. The AstroMaster Series is made of the highest quality materials to ensure stability and durability. All this adds up to a telescope that gives you a lifetime of pleasure with a minimal amount of maintenance.

These telescopes were designed for the First Time Buyer offering exceptional value. The AstroMaster series features a compact and portable design with ample optical performance to excite any newcomer to the world of amateur astronomy.

AstroMaster telescopes carry a two year limited warranty. For details see our website at www.celestron.com

Some of the many standard features of the AstroMaster include:

•All coated glass optical elements for clear, crisp images.

•Smooth functioning, rigid equatorial mount with setting circles in both axes.

•Preassembled steel leg tripod with 1.25” legs ensures stable platform.

•Quick and easy no-tool set up.

•CD-ROM “The Sky” Level 1 --- astronomy software which provides education about the sky and printable sky maps.

•All models can be used terrestrially as well as astronomically with the standard accessories included.

Take time to read through this manual before embarking on your journey through the Universe. It may take a few observing sessions to become familiar with your telescope, so you should keep this manual handy until you have fully mastered your telescope’s operation. The manual gives detailed information regarding each step as well as needed reference material and helpful hints guaranteed to make your observing experience as simple and pleasurable as possible.

Your telescope is designed to give you years of fun and rewarding observations. However, there are a few things to consider before using your telescope that will ensure your safety and protect your equipment.

Warning

Never look directly at the sun with the naked eye or with a telescope (unless you have the proper solar filter). Permanent and irreversible eye damage may result.

Never use your telescope to project an image of the sun onto any surface. Internal heat build-up can damage the telescope and any accessories attached to it.

Never use an eyepiece solar filter or a Herschel wedge. Internal heat build-up inside the telescope can cause these devices to crack or break, allowing unfiltered sunlight to pass through to the eye.

Do not leave the telescope unsupervised, either when children are present or adults who may not be familiar with the correct operating procedures of your telescope.

Figure 1-1 AstroMaster 70 EQ Refractor

1.	Telescope Optical Tube	9.	Latitude Adjustment Screw
2.	Dovetail Mounting Bracket	10.	Tripod Accessory Tray
3.	R.A. Setting Circle	11.	Tripod
4.	Star Pointer Finderscope	12.	Counterweight Bar
5.	Eyepiece	13.	Counterweights
6.	Focus Knob	14.	Equatorial Mount
7.	Dec. Slow Motion Cable	15.	Dec. Setting Circle
8.	R.A. Slow Motion Cable	16.	Objective Lens

Figure 1-2 AstroMaster 114 EQ Newtonian

(AstroMaster 76 EQ Newtonian Similar)

1.	Eyepiece	8.	Tripod Accessory Tray
2.	Tube Ring (not on 76 EQ)	9.	Tripod
3.	Telescope Optical Tube	10.	Counterweights
4.	Primary Mirror	11.	R.A. Setting Circle
5.	Dec. Slow Motion Cable	12.	Equatorial Mount
6.	R.A. Slow Motion Cable	13.	Dec. Setting Circle
7.	Latitude Adjustment Screw	14.	Focus Knob

This section covers the assembly instructions for your AstroMaster telescope. Your telescope should be set up indoor the first time so that it is easy to identify the various parts and familiarize yourself with the correct assembly procedure before attempting it outdoor.

Each AstroMaster comes in one box. The pieces in the box are – optical tube with attached sky pointer and tube rings (114 EQ only), CG-2 equatorial mount, counterweight bar, two counterweights – 2.0 lbs. (0.9kg) for the 70 EQ and 2.6 lbs. (1.2kg) for the 76 EQ & 114 EQ, R.A. & Dec. slow-motion cables, 10mm eyepiece – 1.25”, 20mm eyepiece – 1.25” (erect image for 76 EQ & 114 EQ), erect image diagonal 1.25” (for 70 EQ), “The Sky” Level 1 CD-ROM.

Setting up the Tripod

1.Remove the tripod from the box (Figure 2-1). The tripod comes preassembled so that the set up is very easy.

2.Stand the tripod upright and pull the tripod legs apart until each leg is fully extended and then push down slightly on the tripod leg brace (Figure 2-2). The very top of the tripod is called the tripod head.

3.Next, we will install the tripod accessory tray (Figure 2-3) onto the tripod leg brace (center of Figure 2-2).

4.Insert the cut-out in the center of the tray (flat side of the tray facing down) to match the center of the tripod leg brace and push down slightly (Figure 2-4). The ears of the tray should appear as in Figure 2-4.

Figure 2-1

Figure 2-2

Figure 2-3

Figure 2-4

5.Rotate the tray until the ears are under the leg brace support of each leg and push slightly and they will lock in place (Figure 2-5). The tripod is now completely assembled (Figure 2-6).

6.You can extend the tripod legs to the height you desire. At the lowest level the height is 24” (61cm) and extends to 41” (104cm). You unlock the tripod leg lock knob at the bottom of each leg (Figure 2-7) and pull the legs out to the height you want & then lock the knob securely. A fully extended the tripod looks like the image in Figure 2-8.

7.The tripod will be the most rigid and stable at the lowest height.

Figure 2-5

Figure 2-6

Figure 2-7

Figure 2-8

Attaching the Equatorial Mount

The equatorial mount allows you to tilt the telescopes axis of rotation so that you can track the stars as they move across the sky. The AstroMaster mount is a German equatorial mount (CG-2) that attaches to the tripod head. To attach the mount:

1.Remove the equatorial mount from the box (Figure 2-10). The mount has one latitude adjustment screws (latitude locking bolt) attached to and the other one attaches to the threaded hole in the mount (see area in Figure 2-24).

2.The mount will attach to the tripod head and more specifically to the knob with bolt attached under the tripod head (Figure 2-9). Push the mount (large flat portion with a small tube sticking out) into the center hole of the tripod head until it is flush and hold it steady. Then, reach under the tripod head with your other hand and turn the knob which will thread into the bottom of the mount. Continue turning until it is tight. The completed assembly of the mount to the tripod is seen in Figure 2-11.

Figure 2-9

Figure 2-10

Figure 2-11

Installing the Counterweight Bar & Counterweights

To properly balance the telescope, the mount comes with a counterweight bar and two counterweights. To install them:

1.Remove the counterweight safety screw (orange color) from the counterweight bar (at the opposite end of the threaded rod) by unthreading it counterclockwise – see Figure 2-12.

2.Install the large threads of the counterweight bar into the threaded hole in the Dec. axis of the mount -- see Figure 2-13 until it is tight. Now you are ready to attach the counterweights.

3.Orient the mount so that the counterweight bar points toward the ground.

4.Loosen the locking knob on the side of each counterweight (it doesn’t matter which counterweight you attach first) so that the threads do not protrude through the center hole of the counterweights.

5.Slide one of the counterweights onto the counterweight bar about half way up and tighten the locking knob securely. The correct orientation of the weights is shown in Figure 2-14.

6.Slide the second counterweight onto the counterweight bar flush up against the first one and then lock securely.

7.Replace the safety screw and thread it on securely. The completed assembly is shown in Figure 2-14.

Figure 2-12

Figure 2-13

Figure 2-14

Attaching the Slow Motion Cables

The AstroMaster mount comes with two slow motion control cables that allow you to make fine pointing adjustments to the telescope in both R.A. and Declination. To install the cables:

1.Locate the two cables with knobs on them (both are identical is size and length) and make sure the screw on each cable end does not protrude through the opening.

2.Slide the cable onto the R.A. shaft as far as it will go. There are two R.A. shafts, one on either side of the mount. It makes no difference which shaft you use since both work the same (unless you are using a motor drive). Use whichever one you find more convenient.

3.Tighten the screw on the R.A. cable to hold it securely in place.

4.The DEC. slow motion cable attaches in the same manner as the R.A. cable. The shaft that the DEC. slow motion knob fits over is toward the top of the mount, just below the telescope mounting platform.

Figure 2-15	Figure 2-16
R.A. Shaft on bottom and Dec. Shaft on top	R.A. & Dec. Cables with knobs attached

Attaching the Telescope Tube to the Mount

The telescope optical tube attaches to the mount via a dovetail slide bar mounting bracket at the top of the mount (Figure 2-16). For the 114 EQ Newtonian, the mounting bar is the bracket which is attached to the tube rings. For the 70 EQ refractor and the 76 EQ Newtonian the mounting bar is attached along the bottom of the telescope tube.

Before you attach the optical tube, make sure that the declination and right ascension locking knobs are tight (Figure 2-17). Then, make sure that the latitude adjustment screws (Figures 1-1 & 1-2) are tight. This will ensure that the mount does not move suddenly while attaching the telescope optical tube. Also, remove the objective lens cap (refractor) or the front opening cap (Newtonian). To mount the telescope tube:

1.Remove the protective paper covering the optical tube. You will have to remove the tube rings on the 114 EQ Newtonian before removing the paper.

2.Loosen the mounting knob and the mounting safety screw on the side of the dovetail mounting platform so they do not protrude into the mounting platform – see Figure 2-18.

3.Slide the dovetail mounting bar into the recess on the top of the mounting platform (figure 2-17).

4.Tighten the mounting knob on the dovetail mounting platform to hold the telescope in place.

5.Hand tighten the mounting platform safety screw until the tip touches the side of the mounting bracket.

NOTE: Never loosen any of the knobs on the telescope tube or mount other than the R.A. and DEC knobs.

Hint: For maximum rigidity of the telescope and mount, make sure the knobs/screws holding the tripod legs to the tripod head are tight.

Figure 2-17

Dec. Lock Knob on top of Dec. circle & R.A. Lock Knob on top of R.A. circle

Figure 2-18

Mounting Knob & Safety Screw in the dovetail bracket Shown is the 114 EQ telescope tube

Installing the Diagonal & Eyepiece (refractor)

The diagonal is a prism that diverts the light at a right angle to the light path of the refractor. This allows you to observe in a position that is more comfortable than if you looked straight through. This diagonal is an erect image model that corrects the image to be right side up and oriented correctly left-to-right which is much easier to use for terrestrial observing. Also, the diagonal can be rotated to any position which is most favorable for you. To install the diagonal and eyepieces:

1.Insert the small barrel of the diagonal into the 1.25” eyepiece adapter of the focus tube on the refractor – Figure 2-19. Make sure the two thumbscrews on the eyepiece adapter do not protrude into the focuser tube before installation and the plug up cap is removed from the eyepiece adapter.

2.Put the chrome barrel end of one of the eyepieces into the diagonal and tighten the thumb screw. Again, when doing this make sure the thumb screw is not protruding into the diagonal before inserting the eyepiece.

3.The eyepieces can be changed to other focal lengths by reversing the procedure in step 2 above.

Installing the Eyepiece on the Newtonians

The eyepiece (or ocular) is an optical element that magnifies the image focused by the telescope. Without the eyepiece it would be impossible to use the telescope visually. Eyepieces are commonly referred to by focal length and barrel diameter. The longer focal length (i.e., the larger the number) the lower the eyepiece magnification (i.e., power). Generally, you will use low-to-moderate power when viewing. For more information on how to determine power, see the section on “Calculating Magnification”. The eyepiece fits directly into the focuser of the Newtonians. To attach the eyepieces:

1.Make sure the thumbscrews are not protruding into the focuser tube. Then, insert the chrome barrel of the eyepieces into the focus tube (remove the plug up cap of the focuser first) and tighten the thumbscrews – see Figure 2-20.

2.The 20mm eyepiece is called an erecting eyepiece since it corrects the image so it is right side up and corrected left to right. This makes the telescope useful for terrestrial viewing.

3.The eyepieces can be changed by reversing the procedure as described above.

Figure 2-19

Figure 2-20

Moving the Telescope Manually

In order to properly use your telescope, you will need to move your telescope manually at various portions of the sky to observe different objects. To make rough adjustments, loosen the R.A. and Dec. locking knobs slightly and move the telescope in the desired direction. To make fine adjustments, when the knobs are locked you turn the slow motion cables.

Both the R.A. and Dec. axis have locking knobs to clutch down each axis of the telescope. To loosen the clutches on the telescope, unlock the locking knobs.

Figure 2-21

Dec. Lock Knob on top of Dec. circle & R.A. Lock Knob on top of R.A. circle

Balancing the Mount in R.A.

To eliminate undue stress on the mount, the telescope should be properly balanced around the polar axis. In addition, proper balancing is crucial for accurate tracking if using an optional motor drive. To balance the mount:

1.Release the R.A. lock knob (see figure 2-21) and position the telescope off to one side of the mount (make sure that the dovetail mounting bracket knob is tight). The counterweight bar will extend horizontally on the opposite side of the mount (see figure 2-22).

2.Release the telescope — GRADUALLY — to see which way the telescope “rolls” or falls.

3.Loosen the counterweight locking knob on the counterweights (one at a time).

4.Move the counterweights to a point where they balance the telescope (i.e., it remains stationary when the R.A. lock knob is released).

5.Tighten the locking knobs to hold the counterweights in place.

Balancing the Mount in Dec.

The telescope should also be balanced on the declination axis to prevent any sudden motions when the Dec. lock knob (Fig 2-21) is released. To balance the telescope in Dec.:

1.Release the R.A. locking knob and rotate the telescope so that it is on one side of the mount (i.e., as described in the previous section on balancing the telescope in R.A.).

2.Lock the R.A. locking knob to hold the telescope in place.

3.Release the Dec. locking knob and rotate the telescope until the tube is parallel to the ground (figure 2-23).

4.Release the tube — GRADUALLY — to see which way it rotates around the declination axis. DO NOT LET

GO OF THE TELESCOPE TUBE COMPLETELY!

5.For the 114 EQ Newtonian, loosen the screws that hold the telescope tube inside the tube rings and slide the telescope either forwards or backwards until it remains stationary when the Dec. lock knob is released. For the 76 EQ Newtonian and 70 EQ refractor, loosen the mounting knob and safety screw on the dovetail mounting bracket (Figure 2-18) and slide the telescope tube slightly in either direction until it remains stationary when the Dec. lock knob is released.

6.Tighten the tube ring screws firmly to hold the telescope in place on the 114 EQ. For the 76 EQ and the 70 EQ, tighten the mounting knob and then the safety screw on the dovetail mounting bracket.

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