Meade 883 Instruction Manual

Operating Instructions

#883 Deluxe Field Tripod

For use with the ETX-90RA, ETX-90EC, and ETX-125EC Astro Telescopes

P ARTS LISTING AND ASSEMBLY

When opening the packing box for the first time, note carefully
the following parts included with the full-length #883 Deluxe
Field Tripod:

• Tripod

• 2 Attachment Knobs (with 1/4-20 threads)

• Accessory Tray

Preparing the Tripod For Use

The #883 Deluxe Field Tripod (Fig. 1) is simple to set up and
easy to use. Users need only attach the accessory tray and
adjust the tripod to the desired observing height.

1. Extending the Tripod

Remove the tripod from the packing box and stand it
upright. Grasp two of the tripod legs, leaving the full
weight of the tripod on the third leg. Gently pull the legs
apart to a full open position.

2. Attaching the Accessory Tray

Remove the round accessory tray (7, Fig. 1) from the
packing box. Remove the black, star-shaped lock knob
from the threaded rod on the bottom of the accessory tray.
Attach the tray to the tripod by inserting the threaded rod
through the central hub of the extension strut (8, Fig. 1).
Rethread the lock knob onto the accessory tray.

3. Varying the Tripod Height

Loosen the black, star-shaped height adjustment knob
(6, Fig. 1) at the base of each tripod leg. Slide the three
inner tripod leg sections to the desired height. Tighten the
three height adjustment knobs to a “firm feel.” Do not
overtighten.

NOTE: The tripod legs do not all have to be extended to exactly
the same length. Vary the height of one or more tripod legs as
required to achieve an approximately level mounting surface
for the telescope, as shown by the bubble level (5, Fig. 1).

4. Collapsing the Tripod for Storage

Remove the accessory tray (7, Fig. 1) from the tripod.
Grasp the top of the tripod with one hand, and with the
other hand, pull up on the central hub of the extension
strut (8, Fig. 1) where the accessory tray was attached.
This action will cause the tripod legs to move inward to a
collapsed position.

Important Note: If the tripod does not extend or collapse
easily, do not force the tripod legs in or out. By following the
above instructions the tripod will function properly. Forcing the
tripod into an incorrect position may damage the extension strut
system.

Attaching an ETX Astro Telescope to the Tripod

1. Confirm that the latitude lock lever (12, Fig. 1) is in the
locked position by rotating the lever clockwise until tight. If
using the ETX-90RA model, confirm that the N/S switch
on the bottom of the drive base of the telescope is set for
the correct hemisphere prior to mounting.

2. On the side of the
telescope drive base,
locate the two table
tripod attachment hole
covers (Fig. 2).

NOTE: These holes are
for the optional table
tripod and are used for
location purposes only
with the field tripod.

3. Locate the field tripod mounting hole on the bottom of the
drive base that is closest to the hole covers located in
step 3. Slightly thread one of the provided 1/4-20
attachment knobs into the hole.

4. Place the telescope base on the tripod mounting plate
(2, Fig. 1), aligning the knob inserted in step 3 with the
mounting slot (1, Fig. 1) located directly above the “N”
tripod leg (8, Fig. 1). Slide the knob into the slot, then
position the telescope base so that the second field tripod
mounting hole lines up with the second mounting slot.

5. Thread the second 1/4-20 knob through the slot and into
the hole in the telescope drive base. Tighten both knobs
to a firm feel only to secure the telescope to the tripod. Do

not overtighten or damage to the threads may occur.

The #883 Deluxe Field Tripod provides for two alignment
configurations of ETX Astro Telescope models: Alt/Az and polar.

AL T/AZ ALIGNMENT

Alt/Az alignment (Fig. 3) is best used for terrestrial (land)
viewing and for casual celestial observation. The telescope’s
manual slow-motion controls (ETX-90RA) or the Electronic
Controller arrow keys

(ETX-90EC and ETX-125EC)

are used to

keep the object within the field of view.

NOTE: Fully automatic tracking of celestial objects can be
accomplished in the Alt/Az configuration using the optional
#497 Autostar Computer Controller with the ETX-90EC and
ETX–125EC. The ETX-90RA must be polar-aligned to
automatically track celestial objects (see

POLAR ALIGNMENT

).

In Alt/Az viewing applications, the three legs of the #883 Deluxe
Field Tripod may be positioned in an arbitrary orientation. The
telescope mounting, however, should be placed in a horizontal
position by turning the fine latitude adjustment knob (4, Fig. 1) until
the latitude scale (3, Fig. 1) reads 90°, unlocking and re-locking the
latitude lock knob (11, Fig. 1) to accomplish this adjustment.

NOTE: The ETX-90RA motor drive should be turned off in
terrestrial applications.

Fig. 1: #883 Deluxe Field Tripod.

1

1

11

12

10

9

8

3

2

4

6

7

Fig. 2: Drive Base of the ETX-90RA
showing attachment holes covers
standard on all ETX telescopes.

1. Mounting Slots

2. Mounting Plate

3. Latitude Scale

4. Fine Latitude
Adjustment Knob

5. Bubble Level

6. Height Adjustment
Knob

7. Accessory Tray

8. Extension Strut
System

9. North-Pointing
Tripod Leg (marked
“N” at position of
arrow)

10. Fine Azimuth
Adjustment Knobs

11. Latitude Lock Knob

12. Latitude Lock Lever

(opposite side)

5

POLAR ALIGNMENT

Polar alignment (Fig. 3) is the process of lining up the
telescope’s polar axis with the North Celestial Pole (or South
Celestial Pole if observing from the southern hemisphere).

With a polar-aligned telescope, tracking celestial objects is
possible by simply turning on the drive motor in the base of the
telescope. The motor counteracts the Earth’s rotation, keeping
objects in the field of view. Also, with a polar-aligned telescope,
the telescope’s R.A. and Dec setting circles may be used to
locate faint objects directly from their catalogued coordinates.

Polar Alignment Procedure

Make sure the telescope is firmly attached to the tripod, as
described above, with the latitude lock knob (11, Fig 1) and the
latitude lock lever (12, Fig. 1) firmly locked.

Step 1 below is equivalent to pointing the telescope’s polar axis
due north (or due south for observers in the southern
hemisphere). Step 2 is equivalent to making the telescope’s
latitude angle equal to the latitude angle of your observing
location.

1. On top of one of the tripod legs, locate the letter "N"
(9, Fig. 1). This represents the north leg of the tripod. Pick
up the entire telescope-and-tripod and place the tripod so
that the leg marked "N" points due north. For observers in
the southern hemisphere (e.g., Australia, South America,
Africa, etc.), the leg marked "N" should point due south.

2. Determine the latitude of your observing location from a
road map, atlas, or refer to the telescope instruction
manual. To set the latitude of the tripod to your observing
location, loosen the latitude lock knob (11,Fig. 1). Turn the
fine latitude adjustment knob (4, Fig. 1) clockwise or
counterclockwise until the latitude pointer indicates the
correct latitude on the latitude scale (3, Fig. 1).

It may be necessary to loosen the lock nut on the fine
latitude adjustment knob (4, Fig. 1) to allow enough
movement of the mount to achieve the latitude of your
location. Once the desired latitude has been set, tighten
the lock nut until it is flush against the mount. Tighten the
latitude lock knob (11, Fig. 1) as well.

NOTE: The fine azimuth adjustment knobs (9, Fig. 1), which
move the telescope horizontally without moving the tripod itself,
may be used to aid in the alignment procedure.

By following the above procedure, the telescope is polar­aligned for most celestial observing applications. Approximate
polar alignment is sufficient in the great majority of these
applications.

Important Note: For almost all astronomical observing
requirements, approximate settings of the telescope’s latitude
and polar axis are acceptable! Do not allow undue attention to
precise polar alignment of the telescope to interfere with your
basic enjoyment of the instrument.

Using the North Star (Polaris) to find North will aid in polar
alignment. Polaris can be found in relation to the Big Dipper by
projecting a line from the so-called “pointer stars” of the Big
Dipper (Fig. 4). For southern hemisphere alignment, locate
south by using the faint star Sigma Octans (the South Star).

Using a Polar-Aligned Telescope

Once the telescope is polar-aligned, the telescope motor drive
will keep a celestial object in the field of view of the telescope.

1. To center a celestial object within a polar-aligned
telescope, see the appropriate section in the telescope’s
instruction manual (for the ETX-90RA model, see
Locating Astronomical Objects; for ETX-90EC and
ETX–125EC models, see Observing with the Electronic
Controller). Do not move the tripod or adjust the latitude
angle when centering an object in the telescope as this
will destroy the polar alignment.

2.

Activate the telescope’s motor drive. The motor drive keeps

celestial objects within the telescope's field of view.

• ETX-90RA: The On/Off switch is located on the

bottom of the drive base.

• ETX-90EC or ETX–125EC: See the Modes of

Operation section of the telescope’s instruction
manual.

NOTE:Depending on the accuracy of the alignment procedure,
it may be necessary to use the R.A. and Dec slow-motion
controls (ETX-90RA) or the Electronic Controller arrow keys
(ETX-90EC or ETX-125EC), to make minor adjustments to
keep celestial objects in the field of view.

3. The motor drive disengages when the R.A. and Dec lock
levers are unlocked and re-engages when the lock levers
are locked, making it possible for the motor drive to
remain on during an entire observing session.

4. At the end of an observing session, remember to turn off
the motor drive.

If you have a question concerning use of the #883 Deluxe Field
Tripod, call the Meade Instruments Customer Service
Department at [phone], or fax at [phone].
Customer Service hours are 8:30 AM to 4:30 PM, Pacific Time,
Monday through Friday.

Fig. 4: Locating Polaris.

Version 0799 14-4010-01

Fig. 3: Examples of Alt/Az (left) and polar mounting (right) of an
ETX-90EC to the #883 Deluxe Field Tripod.

ALT/AZ:
Tripod head
locked at 90°

POLAR:
Tripod head
locked at
observer’s
latitude

Meade Instruments Corporation

World’s leading manufacturer of astronomical telescopes for the serious amateur.

6001 OAK CANYON, IRVINE, CALIFORNIA 92620-4205 U.S.A.

[phone] ■FAX: [phone] ■www.meade.com

Little Dipper

Polaris

Big Dipper

Cassiopeia