Orion EQ-13 User manual

INSTRUCTION MANUAL
IN 672 Rev B 8-22
Orion®EQ-13 Equatorial
Telescope Mount and Tripod
#55026
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2022 Orion® Telescopes & Binoculars.All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modied or adapted, without the prior written consent of Orion Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY

2
I. Parts
Part Qty
A — Tripod 1
B — Equatorial mount 1
C — Accessory tray 1
D — Latitude adjustment T-bolt 2
E — Slow-motion cables 1
F — Counterweight shaft 1
G — Counterweightt 1
Figure 1. Included components of the Orion EQ-13 Equatorial Mount.
2
Congratulations on your purchase of an Orion telescope mount. Your new EQM-13 Equatorial Mount
and Tripod is quality equatorial mount designed for astronomical viewing with small telescopes. These
instructions will help you assemble and properly use your new mount. Please read them over thoroughly
before getting started.
G
F E
D
B
A
CB
WARNING: Do NOT look at the Sun without a
professionally made solar filter on the telescope;
serious eye damage may result if you look at the
Sun with any unfiltered optical instrument. Do not
leave the telescope unsupervised around children.
Always cover the lenses when leaving the telescope
in direct sunlight.

3
II. Assembly
1. Spread the tripod (A) legs apart and stand the tripod on
the ground. You can extend the legs to the desired height
later using the leg lock knobs. For now just keep them fully
retracted.
2. Attach the accessory tray (C) by registering its center cut-
out over the center of the tripod leg brace assembly (Figure
2A). Press the tray down and twist it until the tray tabs click
in place under the three retaining clips on the brace (2B).
3. Now you will attach the equatorial mount (B) to the tripod.
Place the base of the mount onto the tripod’s mounting
platform, and then simply thread the captive mount attach-
ment knob under the tripod clockwise up into the mount
until it is tight (Figure 3).
4. Next, thread the second latitude adjustment T-bolt (D) into
the hole in the mount base. (One T-bolt comes pre-installed;
the other one you must install yourself.) Figure 3 shows the
two installed latitude adjustment T-bolts.
5. Install the counterweight shaft (F) by threading it into the
counterweight shaft collar (Figure 4A).
6. Now remove the safety stop at the end of the shaft and
slide counterweight (G) onto the shaft (Figure 4B). You
may have to loosen the counterweight lock knob to allow
the weight to slide onto the shaft. Once the counterweight
is on the shaft, replace the safety stop.
7. Attach the two slow-motion cables (E) to the RA and Dec
gear shafts by threading the collar on the gear shaft onto
the cable until tight (Figure 5).
The EQ mount is now fully assembled.To install an optical tube
on the mount, make sure the tube is equipped with a compat-
ible Vixen-style dovetail bar.
III. Installing a Telescope
Optical Tube On the Mount
Before installing an optical tube, ensure that the right ascen-
sion and declination lock knobs (Figure 6) are tightened so
that the mount won’t swivel accidentally when you’re attaching
the tube rings or the optical tube. And of course make sure
the counterweight is installed on the counterweight shaft.
Make sure the two saddle clamp knobs are backed out suf-
ciently to allow the dovetail bar to seat properly. Then lift the
optical tube and set the dovetail mounting bar into the mount’s
saddle. When the dovetail bar is seated in the saddle, tighten
the saddle clamp knobs until tight.
IV. Balancing the Telescope
To insure smooth movement of the telescope on both axes
of the equatorial mount, it is imperative that the optical tube
be properly balanced. First we’ll balance the telescope with
respect to the R.A. axis, then the Dec. axis.
1. Keeping one hand on the telescope optical tube (sold
separately), loosen the R.A. lock knob (see Figure 7A).
Make sure the Dec. lock knob is locked, for now. The tele-
scope should now be able to rotate freely about the R.A.
axis. Rotate it until the counterweight shaft is parallel to the
ground (i.e., horizontal), as in Figure 7A.
2. Now loosen the counterweight lock knob and slide the
weight along the shaft until it exactly counterbalances
the telescope. That’s the point at which the shaft remains
horizontal even when you let go of the telescope with both
hands.
3. Retighten the counterweight lock knob. The telescope is now
balanced on the R.A. axis.
4. To balance the telescope on the Dec. axis, rst tighten the
R.A. lock knob, with the counterweight shaft still in the hori-
zontal position.
5. With one hand on the telescope optical tube, loosen the
Dec. lock knob (see Figure 7B). The telescope should now
Figure 2. A) Place center of accessory tray over the center of the
leg brace assembly. B) Press down and twist tray until the tabs click
under retaining clips.
Figure 3. Secure the EQ mount to the tripod with the mount
attachment knob.
Tray tab
Retaining
clip
Latitude
adjustment
T-bolt
Mount
attachment
knob
Latitude
adjustment
T-bolt
(need to
install)
(pre-
installed)
A. B.

4
be able to rotate freely about the Dec. axis. If the front of
the telescope swings downward, that means you need to
move it back in the mount’s saddle. If the front of the tele-
scope swings upward, then you need to shift the telescope
forward in the saddle. To move the telescope in the saddle,
loosen the saddle lock knobs just a little – so the dovetail
bar doesn’t accidentally pop out of the saddle. Position the
telescope so it remains horizontal when you carefully let go
with both hands. This is the balance point.
6. Retighten the saddle clamp knobs.
The telescope is now balanced on both axes. Now when you
loosen the lock knob on one or both axes and manually point
the telescope, it should move without resistance and should
not drift from where you point it.
V. Polar Alignment
When you look at the night sky, you no doubt have noticed that
the stars appear to move slowly from east to west over time.
That apparent motion is caused by the Earth’s rotation (from
west to east). An equatorial mount is designed to compensate
for that motion, allowing you to easily “track” the movement of
astronomical objects, thereby keeping them from drifting out of
your telescope’s eld of view while you’re observing.
This is accomplished by slowly rotating the telescope on its
right ascension (R.A.) axis, using only the R.A. slow-motion
knob. But rst the R.A. axis of the mount must be aligned
with the Earth’s rotational (polar) axis—a process called polar
alignment.
For Northern Hemisphere observers, approximate polar align-
ment is achieved by pointing the mount’s right ascension axis
at the North Star, Star (Polaris). It lies within 1° of the north
celestial pole (NCP), which is an extension of the Earth’s rota-
tional axis out into space. Stars in the Northern Hemisphere
appear to revolve around the NCP.
To nd Polaris in the sky, look north and locate the pattern
of the Big Dipper (Figure 8). The two stars at the end of the
“bowl” of the Big Dipper point approximately to Polaris.
Observers in the Southern Hemisphere aren’t so fortunate to
have a bright star so near the south celestial pole (SCP). The
star Sigma Octantis lies about 1° from the SCP, but it is barely
visible with the naked eye (magnitude 5.5).
To polar align the equatorial mount:
1. Roughly level the mount by adjusting the length of the three
tripod legs as needed (Figure 9).
Figure 4. A) Thread the counterweight shaft onto the mount.
B) After removing the safety stop, slide the counterweight onto the
shaft.
Figure 5. Attach the two slow-motion cables to the mount.
Figure 6. The assembled EQ-13 mount looks like this.
A. B.
Safety stop
Dec. slow-motion
cable
R.A. slow-motion
cable
Saddle
clamp
knobs
Dec. lock knob
R.A. lock knob
Dovetail
saddle
R. A. (Polar) axis
Dec. axis
To Polaris
Slow motion
cable

5
2. Loosen the latitude lock knob a half turn or so (Figure 10).
3. Using the two latitude adjustment T-bolts, set the latitude so
that the pointer on the latitude scale indicates the latitude
of your observing location. (Loosen one latitude adjustment
T-bolt before tightening the other.) If you don’t know your
location’s latitude, you can look it up on the internet. For
example, if your latitude is 35° North, set the pointer to 35.
Then retighten the latitude lock knob. The latitude setting
should not have to be adjusted again unless you move to a
different viewing location some distance away.
4. Next, loosen the mount attachment knob (see Figure 10) just
enough to allow you to rotate the mount in azimuth. Then
rotate the mount by hand so the R.A. axis points rough-
ly at Polaris (Figure 6). If you cannot see Polaris directly
from your observing site, consult a compass and rotate the
mount so the telescope points North. Then retighten the
mount attachment knob.
The equatorial mount is now (roughly) polar aligned. From
this point on in your observing session, you should not
make any further adjustments to the azimuth or the lati-
tude of the mount, nor should you move the tripod. Doing
so will ruin the polar alignment. The telescope should
henceforth be moved only about its R.A. and Dec. axes.
Figure 7. A) Balance a telescope in right ascension by sliding the counterweight along the shaft until it counterbalances the telescope. B)
Balance the telescope on the declination axis by sliding the dovetail mounting bar forward or back in the mount’s saddle.
A. B.
R.A. lock knob
Saddle
clamp
knobs
Counterweight lock
knob
Counterweight
shaft
Dec. lock knob
Figure 8. To nd Polaris in the night sky, look north and nd the
Big Dipper. Extend an imaginary line from the two "Pointer Stars" in
the bowl of the Big Dipper. Go about ve times the distance between
those stars and you'll reach Polaris, which lies within 1° of the north
celestial pole (NCP).
Big Dipper
(in Ursa Major)
Little Dipper
(in Ursa Minor)
Cassiopeia
N.C.P.
Pointer
Stars
Polaris

6
VI. Using the EQ-13 Mount
Using the R.A. and Dec. Slow-Motion Control
Cables
The R.A. and Dec. slow-motion control cables (see Figure 6)
allow ne adjustment of the mount’s position to center objects
within the telescope’s eld of view. Before using the cables,
manually “slew” the mount to point the telescope in the vicinity
of the desired target. Do this by loosening the R.A. and Dec.
lock knobs and moving the telescope about the mount’s R.A.
and Dec. axes. Once the telescope is pointed somewhere
close to the object to be viewed, retighten the mount’s R.A.
and Dec. lock knobs.
The object should now be visible somewhere in the eld of
view of the telescope’s nder scope of reex sight. If it isn’t,
use the slow-motion controls to scan the surrounding area of
s k y. Note: when using the slow motion cables, the R.A.
and Dec lock knobs should be tightened, not loose. When
the object is visible in the nder scope, use the slow-motion
controls to center it. Now, look in the telescope’s eyepiece and
use the slow-motion controls to center it in the eyepiece.
The R.A. slow motion cable can turn the mount’s R.A. axis a
full 360 degrees. However, the Dec. slow-motion cable has a
limited range of about 25 degrees. If you reach the end of the
range of motion – and you cannot turn the knob further – you
should reverse direction by 10 degrees or so, then release
the Dec. lock knob and move the telescope by hand back
Figure 9. Adjust the tripod leg length by loosening the leg lock
knob, then extending the leg to the desired length. Then retighten the
knob.
Figure 10. Loosen the latitude lock knob, then use the two latitude
adjustment T-bolts to set the latitude scale pointer to your location’s
latitude.
Figure 11. The R.A. and Dec. setting circles allow you to locate
an object by its R.A. and Dec. coordinates.
Latitude scale
Dec. setting
circle
R. A. setting
circle
Mount attachment knob
Latitude lock
knob
Latitude
adjustment
T-bolts

7
to about where it was pointed before the slow-motion cable
stopped turning. Now you should be able to use the slow
motion cable again for ne pointing in either direction.
Tracking Celestial Objects
When you observe a celestial object through the telescope,
you’ll see it drift slowly across the eld of view. To keep it in
the eld, assuming the equatorial mount is polar aligned, just
turn the R.A. slow-motion control cable counterclockwise to
track. The Dec. slow-motion control cable is not needed for
tracking. Objects will appear to move faster at higher magni-
cations, because the eld of view is narrower.
Optional Electronic Drive for Automatic Tracking
An optional DC electronic drive is available for the EQM-13
equatorial mount. This battery-operated drive provides auto-
mated, hands-free tracking. Objects will then remain station-
ary in the eld of view without any manual adjustment of the
R.A. slow-motion control cable.
Understanding the Setting Circles
The two setting circles on an equatorial mount enable you to
locate celestial objects by their “celestial coordinates”. Every
object resides in a specic location on the “celestial sphere”.
That location is denoted by two numbers: its right ascension
(R.A.) and declination (Dec.). In the same way, every location
on Earth can be described by its longitude and latitude. R.A.
is similar to longitude on Earth, and Dec. is similar to latitude.
The R.A. and Dec. values for celestial objects can be found in
any star atlas or online planetarium app.
On the EQ-13 mount, the R.A. setting circle is scaled in hours,
from 1 through 24, with small marks in between representing
10-minute increments (Figure 11). The numbers at the base
of the setting circle scale apply to the Northern Hemisphere
while the numbers above them apply to viewing in the
Southern Hemisphere.
The Dec. setting circle is denoted in degrees, with each main
mark representing 10° increments (Figure 11). Values of Dec.
coordinates range from +90° to -90°. The 0° mark indicates
the celestial equator. For this mount, the number scale goes
to 90 on either side of 0 – there are no (+) or (-) signs. When
the telescope is pointed north of the equator, actual values of
Dec. are negative.
For example, the coordinates for the Orion Nebula (M42) are:
R.A. 5 hr 35.4 min, Dec. -5° 27'
That’s 5 hours and 35.4 minutes in right ascension, and -5
degrees and 27 arc-minutes in declination (there are 60 arc-
minutes in 1 degree of declination).
Before you can use the setting circles to locate objects, the
mount must be polar aligned, and the setting circles must be
calibrated. The easiest way to calibrate the setting circles is
to point the telescope at an identiable bright star, center it
in the eyepiece, then set the setting circles to the star’s pub-
lished coordinates, which you can nd in a star atlas or astro-
nomical software program, or perhaps on the internet.
Calibrating the Setting Circles
Using a star atlas or astronomy planetarium program, identify
a bright star visible in your sky. Some smartphone astronomy
apps allow you to hold your phone up to the sky and the app
will identify the stars and constellations visible in the direction
you’re pointing to. Note the right ascension and declination
coordinates of the star.
Let’s take as an example Altair, in the constellation Aquila. Its
coordinates are:
R.A. 19 hr 51 min, Dec 8° 52'
1. Loosen the R.A. and Dec. lock knobs on the equatorial
mount, so the telescope optical tube can move freely.
2. Point the telescope at Altair. Lock the R.A. and Dec. lock
knobs. Center the star in the eyepiece with the slow-motion
control cables.
3. Rotate the R.A. setting circle until the metal arrow indicates
19 hr 51 min.
4. Then rotate the Dec. setting circle until the metal arrow indi-
cates +8° 52'
Note that the setting circles may be a little hard to rotate.
But just grab it rmly around the edge and twist it and it
will rotate.
Finding Objects with the Setting Circles
Now that both setting circles are calibrated, look up the coordi-
nates of an object you wish to view.
1. Loosen the R.A. lock knob and rotate the telescope until
the R.A. value from the star atlas matches the reading on
the R.A. setting circle. Remember to use the lower set of
numbers on the R.A. setting circle if you’re in the Northern
hemisphere. Retighten the lock knob.
2. Loosen the Dec. lock knob and rotate the telescope until
the Dec. value from the star atlas matches the reading on
the Dec. setting circle. Remember that values of the Dec.
setting circle are positive when the telescope is pointing
north of the celestial equator (Dec. = 0°), and negative
when the telescope is pointing south of the celestial equa-
tor. Retighten the lock knob.
Most setting circles are not accurate enough to put an object
dead-center in the telescope’s eyepiece, but they should place
the object somewhere within or near the eld of view of the
nder scope, assuming the equatorial mount is accurately
polar aligned. Use the slow-motion controls to center the object
in the nder scope, and it should appear in the telescope’s eld
of view.
The R.A. setting circle must be re-calibrated every time you
wish to locate a new object. Do so by calibrating the setting
circle for the centered object before moving on to the next one.
Confused About Pointing the Telescope?
Beginners occasionally experience some confusion about how
to point the telescope overhead or in other directions. One
thing you DO NOT do is make any adjustment to the mount’s
latitude setting or to its azimuth position. That will throw off the
mount’s polar alignment. Once the mount is polar aligned, the
telescope should be moved only about the R.A. and Dec. axes.
This is done by loosening one or both of the R.A. and Dec.
lock knobs and moving the telescope by hand, or keeping the
knobs tightened and moving the telescope using the slow-
motion cables.

8
EQ-13 Mount’s Load Capacity
The Orion EQ-13 Equatorial Mount has a load capacity of
13 lbs. That means it can typically support a telescope tube
and its accessories weighing up to 13 lbs. The amount of
weight the mount can stably support will depend somewhat
on the type of telescope, however. For instance, compact tele-
scopes such as Maksutov-Cassegrains have short tubes with-
out much “lever arm,” so they are quite stable on the mount.
Longer telescopes, such as some refractors and Newtonian
reectors have more of a lever arm and thus may wiggle or
vibrate for longer when touched.
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: [phone]
International: [phone]
Customer Support: [email protected]
Copyright © 2022 Orion® Telescopes & Binoculars.All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modied or adapted, without the prior written consent of Orion® Telescopes & Binoculars.
AN EMPLOYEE-OWNED COMPANY
One-Year Limited Warranty
This Orion product is warranted against defects in materials or workmanship for a peri-
od of one year from the date of purchase. This warranty is for the benet of the original
retail purchaser only. During this warranty period Orion Telescopes & Binoculars will
repair or replace, at Orion’s option, any warranted instrument that proves to be defec-
tive, provided it is returned postage paid. Proof of purchase (such as a copy of the origi-
nal receipt) is required. This warranty is only valid in the country of purchase.
This warranty does not apply if, in Orion’s judgment, the instrument has been abused,
mishandled, or modied, nor does it apply to normal wear and tear. This warranty gives
you specic legal rights. It is not intended to remove or restrict your other legal rights
under applicable local consumer law; your state or national statutory consumer rights
governing the sale of consumer goods remain fully applicable.
For further warranty information, please visit www.OrionTelescopes.com/warranty.