Bushnell Refractor Equatorial Mount Instruction Manual

The World’s Easiest Equatorial Mount

Instruction Manual for Refractor Telescopes

Before you get started, you’ll need to know that your telescope is a Refractor telescope.
All telescopes turn the image they receive upside down and backwards. Refractor
telescopes have the ability to turn (erect) or turn the image right side up. Also, some
refractor telescopes can correct the right to left viewing with a special eyepiece. All of
this is especially helpful if what you are looking at is on land as opposed to outer space.

Without getting fancy or technical, equatorial mounts are star finders. Most all of the
visible stars in the sky have an address in a book called a Star Atlas (roadmap of stars)
that is expressed in terms of its Right Ascension and then its Declination. Basically it’s
outer space longitude and then latitude. It will look something like this:

23hr 42min 03sec, 78.3deg N

When using an equatorial mount, you can move your telescope to these settings and find
the star that corresponds to that address. You can purchase a Star Atlas at just about any
bookstore on earth

As well, you will need to be able to locate and identify 2 stars in the sky. The first star
will be the North Star. Coincidentally this star is perfectly north EVERY night you go
out. It is generally around 25 to 45 degrees up from the horizon in North America.

The second star you will need to be able to identify in the sky is a little bit harder. The
second star can really be any star in the sky other than our sun and the North Star. You
can pick a star from a constellation that is in the sky and use a particular star in it. You
will not only have to be able to identify it, but in Step 5 you will need to be able to center
it in the telescope. Unfortunately, there is no other alternative. If you want to use your
equatorial mount, you’ll need to be able to do this. We recommend using a star called
Mizar, as it is visible all months of the year in North America.

In most Star Atlas books there is a section that gives suggestions on which stars to use for
the second star, I recommend using it. Also, there is a section that has the latitude setting
for the North Star in certain areas. You will need this when going through Step 4.

Finally, you will need to set your telescope up to be able to use a Star Atlas. The
following instructions in steps 1-7 will show you how to do this. Good Luck and Have
Fun!!!!!

Table of Contents

Page 1 ….... Introduction

Page 2 ….... Table of Contents

Page 3 ….... Listing of all the Telescope Sections

Page 4 ….... Fine Adjustment Cables

Page 5 ….... The Telescope’s Axis’s

Page 6 ….... The Different Lenses

Page 7 ….... Figuring the Magnification

Page 8 …… The Lens Combinations

Page 9 ….... Aligning the Finderscope

Page 10 …...Aligning the Finderscope continued
Page 11 ….. Aligning the Finderscope continued
Page 12 ….. Step 1 – Getting the Mount at Right Angles
Page 13 ….. Step 2 – Facing the Telescope North
Page 14 ….. Step 3 – Putting in the Eyepiece
Page 15 ….. Step 4 – Finding the North Star
Page 16 ….. Step 5 – Setting the Declination Dial to 90 degrees
Page 17 ….. Step 6 – Finding the Second Star – Its Declination Address
Page 18 ..… Step 7 – Finding the Second Star – Its Right Ascension Address
Page 19 ….. Keeping the Telescope Aligned

Declination
Lock Knob

Declination
Setting

Right

Ascension

Lock

Knob

Right

Ascension

Setting

Latitude

Lock Knob

Latitude
Adjustment
Knob

Finderscope

Focusing Tube That you put

the eyepieces into and bring
the image into focus by
turning either of the two
Focusing Knobs on the sides.

Counter Weight

Makes Sure the
Telescope Doesn’t
Fall Because Of
Uneven Weight

Counterweight Shaft

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22
21
20
19
18

Horizontal Axis
Setting – If there

are numbers on this
just ignore them.
Only in step 2 will
you ever turn the
telescope here.

Telescope Tube

Horizontal
Axis Setting
Lock Knob

3

End That
Faces What
You Are
Looking At.
Never look at
the sun.

Fine Adjustment Cables

The fine adjustment cables move the declination and right ascension settings in very
small increments. When you are aligning the finderscope or centering a star or planet in
the telescope there will be a time when only small adjustments will be necessary. That is
when you’ll use these knobs. They look like the diagram below. Notice one is long and
the other is short. It really doesn’t matter which one goes on the declination and which
one goes on the right ascension. Generally though, they go on just like the below
diagram. They connect to the telescope mount only one way so I won’t cover their
attachment procedure.

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22
21
20
19
18

If your equatorial mount is set up correctly,
you can move just the Right Ascension Fine
Adjustment Knob ONLY to follow any star
across the sky!

4

Declination

Fine

Adjustment

Right

Ascension

Fine

Adjustment

Telescope Axis’s

This instruction manual refers to 3
axis’s in which the telescope will
turn. This diagram illustrates these
axis’s where the telescope can move.

When using your fine
adjustment cables, you’ll
be moving these two
axis’s.

The Different Lenses

There are many different lenses to know about on a refractor telescope. Each has a
specific function that also goes on in a specific order. Below covers these lenses. If you
try different combinations other than what is listed in the next few pages, you will not be
able to see out of your telescope clearly. I’ll introduce you to each of the lenses and their
functions.

The Eyepieces

The Barlow Lens

BARLOW

5

The Erector Lens

ERECTOR

4

The Penta Mirror

3

The Diagonal Mirror

3

4mm Eyepiece

This is the high-powered

eyepiece. It is generally

shorter than the 20mm

eyepiece.

20mm Eyepiece

This is the low-powered

eyepiece. It is generally

taller than the 4mm eyepiece

The Barlow Lens

This piece multiplies the

magnification by generally 2

to 3 times.

Most of the time it will say 2X or

3X on the side of it. Every once in

a while it will even have a different

number.

The Erector Lens

All telescopes turn the image
upside down. This piece can

“erect” the image.

Erecting the image is only available

on Refractor telescopes. Erecting

Lenses generally multiply the

magnification by 1.5 times.

The Penta Mirror

All telescopes make the image appear to move in

the opposite direction as you are turning it from
right to left. The Penta Mirror corrects this and

allows you to look down into the telescope instead

of having to look from behind.

The Diagonal Mirror

The Diagonal Mirror allows you to look down

into the telescope instead of having to look from

behind. It does not correct the right to left

viewing.

It multiplies the magnification

by 2 times.

This piece offers no additional magnification.

As well, most all Refractor telescopes come
with either the Penta Mirror or the Diagonal

Mirror but never with both.

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