IMPORTANT NOTICE! Never use a telescope or spotting scope to look at the Sun! Observing the Sun, even for the shortest fraction of a second, will cause irreversible damage to your eye as well as physical damage to the telescope or spotting scope itself. |
Magellan operates under one of four modes that are cycled by pressing the
MODE key. The four modes are,
- Telescope Mode
- Coordinate Mode
- Timer Mode
- Blank Mode
Some modes have sub-menus accessed by moving the LCD arrow (positioned to
the left of the menu item) up or down using the PREV or NEXT key, and then
pressing ENTER.
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A. Telescope Mode
The default start-up mode for Magellan is Telescope Mode. This mode has telescope
related functions. The sub-menus for this mode are: Object Library, Align,
Date, Encoders and Help. These functions allow the telescope to be aligned
and the object libraries to be accessed for pointing at these objects.
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1. Object Library
This menu item defaults to the top of the menu listing for quick access.
All library data and object search filters are accessed from this menu.
When selected, by pressing the ENTER key, a scrolling menu appears listing
the object library functions. These functions include: Select Object, Object
Information, Start Find, Field, Parameters and User Library.
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a) Select Object
When the Select Object menu is activated by pressing the ENTER key, the
display will offer various object catalogs to be selected. Scroll through
these libraries using the PREV or NEXT keys and select a library by pressing
the ENTER key. When selected, a blinking cursor is displayed, prompting
you to input the catalog number of the desired object. Use the PREV/NEXT
keys to change the digit value and ENTER to fix the value and advance to
the next digit.
Pressing ENTER after the last digit displays the object's description (i.e.
the name, type, magnitude and size or separation). If the object is known
by a common or popular name, this will be displayed first, otherwise the
size and magnitude will be displayed. If the popular name is displayed,
an additional press of ENTER will display the size and magnitude information.
Pressing ENTER again displays the object's coordinates in Right Ascension
and Declination. A third press of ENTER displays the distance to the object
from the telescope's current position. This distance is continually updated
as the telescope is moved, allowing you to steer the telescope to the object.
The MODE key aborts the selected menu item and returns to the previous menu
list.
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b) Object Information
The display shows information about the selected library object. Pressing
ENTER displays the object's description (i.e. the name, type, magnitude
and size or separation). Pressing ENTER again displays the object's coordinates
in Right Ascension and Declination. A third press of ENTER displays the
distance to the object from the telescope's current position. This distance
is continually updated as the telescope is moved allowing you to steer the
telescope to the object.
As you move to various parts of the sky, you may find that object positions
differ slightly from the position indicated by Magellan. These differences
arise from inaccuracies in leveling (squaring) or centering stars during
the initial alignment. You can make minor corrections to the alignment by
"synchronizing" Magellan on any object within the Magellan catalogs.
This is done by centering the known object in the field of view while the
object information for that object is displayed. Press and hold the ENTER
key for one or two seconds and the display will show the message, "Center
object, then press ENTER." Pressing ENTER will now synchronize the
Magellan to the coordinates of the centered object. This will improve the
accuracy of Magellan for objects in the immediate vicinity. While any object
from the object catalogs may be used to "sync" the Magellan, you
may wish to select a bright neighbor of a fainter object to provide the
final pointing accuracy to find that faint object. Appendix A lists the
bright stars from the STAR catalog which may be used for this purpose.
The MODE key aborts the selected menu item and returns to the previous menu
list.
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c) Start Find
Selecting this option filters the library database for objects that match
the specifications listed under the Parameters menu (see below) and displays
the closest object's description (i.e. the name, type, magnitude and size).
Pressing ENTER again displays the object's coordinates in Right Ascension
and Declination. A third press of ENTER displays the distance to the object
from the telescope's current position.
Press NEXT to display the information for the next closest object. PREV
will display the information for the farthest object (or the previous closest
object).
The MODE key aborts the selected menu item and returns to the previous menu
list.
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d) Field
This command identifies objects in the field of view of the telescope. By
pressing ENTER Magellan displays the central object's description (i.e.
the name, type, magnitude and size). Pressing ENTER again displays its coordinates
in Right Ascension and Declination. A third press of ENTER displays the
distance to the object from the telescope's current position.
The MODE key aborts the selected menu item and returns to the previous menu
list.
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e) Parameters
Start Find uses the specifications listed below to filter the database for
matching objects. Scroll through these 6 specifications using the PREV/NEXT
keys and select the ones to change by pressing ENTER.
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1) Type
This menu file option allows you to select the type of CNGC objects you
wish to locate. The symbols GPDCO represent:
G Galaxies
P Planetary Nebulae
D Diffuse Nebulae
C Globular Star Clusters
O Open Star Clusters
Initially, the blinking cursor appears over the G symbol. If you decide
not to look for galaxies, press the PREV/NEXT key and the letter will disappear,
deselecting the GALAXIES category. If you wish to leave GALAXIES selected,
then move the blinking cursor over to one of the other category symbols
by pressing ENTER. You can then deselect the undesired categories.
If you wish to recall a category symbol, move the blinking cursor over the
symbol location and press the PREV/NEXT key. After your selections are made,
press ENTER.
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2) Better
The BETTER menu file option allows you to define the visual object quality
range. At power up, the range is set at the bottom of the scale on VP. When
using the START FIND menu selection, it will select all objects that are
very poor through super or what could be considered an "ALL" setting.
The object quality symbols are:
SU Super
EX Excellent
VG Very Good
G Good
FR Fair
PR Poor
VP Very Poor
If you wish to define the visual object quality range to very good and better,
press ENTER and the blinking cursor will appear on the quality value.
From the quality setting press PREV/NEXT to move to higher or lower quality
settings. Once you have selected the quality value required, press ENTER
to complete the selection process.
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3) Larger
The LARGER menu file option allows settings of the lower apparent size limit
of the objects you wish to see. At power up, it is set to 000' (arc minutes).
In order to make a decision as to the size limits that you may impose, it
helps to have a clear understanding of exactly what an arc minute of sky
is. A good example is the apparent size of the Moon, which could be expressed
as 1/2 degree, 30 arc minutes, or 1800 arc seconds. Each arc minute
is 60 arc seconds, and there are 60 arc minutes for each degree of sky.
Some beginning observers have a tough time discerning objects less than
about 1 arc minute in size unless it is a double star or a planet. Astrophotographers
and those involved with CCD imaging may want to set a higher value based
on a desired image scale coverage that would be most impressive with different
films or types of CCD cameras. Enter the new value in arc minutes by pressing
ENTER to place the cursor on the desired digit and then press PREV/NEXT
to increase or decrease the value of the digit. Pressing ENTER will fix
the value of a digit and move to the next digit until the last digit is
completed, when pressing ENTER will complete the option field.
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4) Smaller
The SMALLER menu file option is the upper size object limit. At power up,
the setting is for 200' arc minutes or 3.33°. This setting is high
enough to cover the largest objects in the OBJECT LIBRARY. You may want
to lower the value because of field-of-view limitations of a particular
eyepiece.
Other reasons for limiting the value in SMALLER is for astrophotographic
or CCD imaging requirements where you don't want the object to exceed the
imaging area of the film or the CCD chip. Setting values by using PREV,
NEXT and ENTER are the same as previously described.
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5) Brighter
The lower brightness limits based on stellar magnitude can be limited in
the BRIGHTER menu file option. At power up, the magnitude value is set to
a very faint level of +20.0.
You may want to adjust the magnitude level to a brighter value starting
at perhaps the limiting visual magnitude of your telescope. Sky conditions
also greatly affect the limiting magnitude due to atmospheric haze, high
clouds, light pollution, or combinations thereof. Setting values by using
PREV, NEXT and ENTER are the same as previously described.
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6) Fainter
The upper level of brightness may also be adjusted with the FAINTER menu
file option, although you may find few applications for limiting it to a
lower value. Setting values by using PREV, NEXT and ENTER are the same as
previously described.
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f) User Library
This option allows the user to create a user library of 125 objects selected
from the existing libraries. Pressing ENTER will display the first of these
125 possible selections. Pressing PREV/NEXT will scroll through these items
with ENTER selecting a particular item. Using PREV/NEXT and ENTER as with
other options, allows new objects to be selected from existing libraries
and added to the User Library.
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2. Align
Alignment of your telescope is the most critical procedure for the successful
use of Magellan. The alignment procedure allows Magellan to determine the
orientation and position of the telescope, and to thereafter guide you accurately
to objects in the sky. Two types of alignment are possible, namely, Polar
and Altazimuth (Altaz). If your telescope is equatorially mounted a polar
alignment is possible, otherwise you will need to use one of the two Altaz
alignment options provided.
The Align function is selected from the menu by pressing the ENTER key when
Align is indicated by the display arrow. Magellan now offers three methods
of alignment (1 Polar and 2 Altaz). If you are equatorially mounted select
the Polar align method, all others must select one of the Altaz methods.
Next to the word "Align" on the Magellan display there is a number
("0" after power is applied). This number represents the quality
of the alignment procedure performed. It is derived from taking the measured
alignment values and comparing them with what should be expected based on
the distances between the alignment objects. A value of 100 (as in 100%)
means that your actual alignment measurements matched those expected based
on calculations. Values between 90 and 110 are accepted but may affect pointing
accuracy when moving to other objects. Values out of this range
are not acceptable and will require that you make another attempt to align
your telescope. The initial value of "0" indicates that Magellan
is not aligned.
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a) Polar Alignment
Polar alignment may be used if your telescope is mounted equatorially. Press
the ENTER key to initiate this function while "Polar" is selected.
Position the telescope/mount system such that it is aligned with the pole
(the pole is in the center of the field of view and the telescope is at
90° Declination. Your telescope instruction manual will provide information
on this initial telescope positioning. Once in position, press
ENTER as requested by the display.
At this point the first alignment star needs to be selected. Press ENTER
and the alignment star catalog will appear. Scrolling with PREV/NEXT,
select a star familiar to you which is near the meridian and press ENTER.
Move the telescope to the selected star and center it in the eyepiece and
press ENTER. At this point polar alignment is complete and you may exit
by pushing the MODE key. Magellan also offers the option of selecting a
second alignment star to further correct alignment inaccuracies in the original
polar positioning of the telescope. The procedure for using the second alignment
star is the same as for the first and Magellan will prompt the user with
display messages.
If errors occur during the alignment procedure Magellan can detect these
based on calculations of expected values. For example, if the wrong star is
centered during alignment, Magellan will detect that the distance between
stars is not what should be expected. If this variation exceeds preset limits,
Magellan will display the message "Alignment Error Check Stars."
If this occurs, press ENTER and begin the alignment procedure again. If
the alignment is successful a number will be displayed next to the "Align"
display which gives a relative value of merit for alignment quality (100
is perfect as in 100%).
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b) Altaz Alignment
There are two choices for the Altaz alignment method. The preferred method
(Altaz Horizontal) requires that you initially start with a bubble level
and the telescope tube in the horizontal position. This is the preferred
method simply because of the reduced physical contortions required by the
user.
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1) Altaz Horizontal
The purpose of this alignment is to find the telescope elevation that is
perpendicular to the azimuth axis of rotation and to instruct the Magellan.
To do this, place a bubble level on the rocker box base of the telescope
under one of the two elevation bearings. The telescope does not need to
be on level ground!! Rotate the telescope base until the bubble level reads
level (this will occur in at least two locations, 180° (apart). Without moving
the telescope from this level position, tilt the telescope tube horizontal
and place the bubble level along the top side of the tube. Adjust the tilt
of the tube until the bubble level again reads level, and press the ENTER
key. Once this horizontal position has been located, you may wish to scribe
lines on the telescope bearing and the side panel to locate the true horizontal
for future alignments. This would be done by simply lining up the scribe
marks and pressing the ENTER key without the need for the bubble level or the preceding
procedure.
You are again instructed to press ENTER and to select an alignment star
from the catalog. By scrolling with PREV/NEXT, select a star familiar to
you and press ENTER. Move the telescope to the selected star, center
it in the eyepiece and press ENTER again. Magellan then offers the selection
of a second alignment star which should be selected and aligned as was the
first star.
If errors occur during the alignment procedure Magellan can detect these
based on calculations of expected values. For example, if the wrong star is
centered during alignment, Magellan will detect that the distance between
stars is not what is expected. If this variation exceeds preset limits,
Magellan will display the message "Alignment Error Check Stars."
If this occurs, press ENTER and begin the alignment procedure again. If
the alignment is successful a number will be displayed next to the "Align"
display which gives a relative value of merit for alignment quality (100
is perfect as in 100%).
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2) Altaz Vertical
This method of alignment requires that the telescope be perpendicular to
the base (parallel to the axis of rotation). This is achieved by placing
the telescope in a vertical position and rotating the base while observing
the star field in the eyepiece. If the telescope is perpendicular to the
base the stars will appear to rotate around the center of the field of view.
Adjust the telescope as required. When you have determined the vertical
position, scribe marks on the base and telescope that will allow this position
to be found in future sessions.
Once the telescope is vertical, press ENTER. You are now instructed to press
ENTER and to select an alignment star from the catalog. By scrolling with
PREV/NEXT, select a star familiar to you and press ENTER. Move the telescope
to the selected star, center it in the eyepiece and press ENTER again.
Magellan then offers the selection of a second alignment star which should
be selected and aligned as was the first star.
If errors occur during the alignment procedure Magellan can detect these
based on calculations of expected values. For example, if the wrong star is
centered during alignment, Magellan will detect that the distance between
stars is not what should be expected. If this variation exceeds preset limits,
Magellan will display the message "Alignment Error Check Stars."
If this occurs, press ENTER and begin the alignment procedure again. If
the alignment is successful a number will be displayed next to the "Align"
display which gives a relative value of merit for alignment quality (100
is perfect as in 100%).
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3. Date
The date is required to locate planets and is in Month/Day/Year format.
The date can be altered by pressing ENTER to select the date function. This
causes the cursor to blink on the first date digit. The value of each digit
is changed and selected by using the PREV/NEXT and ENTER keys. After the
last digit of the year is selected pressing ENTER will complete the date
function.
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4. Encoders...
This function is used to select the encoder specifications used on the telescope.
The default values are correct for high resolution encoders shipped with
your telescope. If the standard value of the encoder is different due to a change
in gear ratios, a note will appear in the installation instructions which
will direct you to change this ratio setting. ENTER, PREV and NEXT are used
to select and modify these numbers as in previous functions.
Caution Dobsonian Owners!! It is possible to install the elevation encoder
on either side of the rocker base. These two locations cause the encoder
to rotate in opposite directions giving different readings to the Magellan.
The Magellan is initialized to expect the elevation encoder bracket to be
installed on the side panel with the clamp attaching near the back plate
of the rocker base. If the encoder is installed properly the reading will
decrease as the telescope is moved from the vertical to the horizontal position.
If this is not the case, move the encoder to the other side of the rocker
box, otherwise, alignment will not be possible.
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5. Help...
A very brief description of Magellan functions is given by this option.
Pressing ENTER will display the help messages and the PREV/NEXT keys move
the user through this text. Pressing the MODE key will end the help session.
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B. Coordinate Mode
This mode displays the direction coordinates of the telescope (where it
is pointing). If the telescope has been aligned the display will show RA
and DEC values. If alignment has not been accomplished the display will
show the raw encoder counts.
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1. Encoder Display
This display shows raw encoder counts. As the telescope is moved these values
will increase or decrease depending on the direction of movement and axis
involved. This display will quickly show any malfunctions in the encoder
system or cables.
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2. Coordinate Display
If the telescope has been aligned, the display will be in RA and DEC values.
You will see the RA = and DEC = coordinates of where the telescope is pointing.
If you move the telescope, the coordinates display will immediately update
the new position in Right Ascension (RA) and Declination (DEC).
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C. Timer Mode
The timer mode displays the stop watch timer and the current time.
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1. Timer
This function allows the user to measure precise time periods for such activities
as photographic time exposures. The timer display shows time remaining in
Hours:Minutes:Seconds. The timed duration is set by holding the ENTER key
for more than one second while the timer display is present and selected.
The cursor will appear in the hours position of the display and will respond
to the PREV/NEXT and ENTER keys to set the values of each digit. After the
last digit of the seconds position is completed, pressing ENTER will return
the display to the original condition. A short duration press of ENTER will
start the timer counting down. Pressing ENTER quickly will toggle the timer
from running to stopped and stopped to running. When running the timer will
continue to count down even if the display is not visible. Upon returning
to the timer display the time remaining will be accurate and available to
the user.
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2. Local Time
The local time display shows local time as entered by the user. It will
start at 00:00:00 when power is turned on. Local time is set by holding
the ENTER key for more than one second while the Local display is present
and selected. The cursor will appear in the hours position of the display
and will respond to the PREV/NEXT and ENTER keys to set the values of
each digit. After the last digit of the seconds position is completed, pressing
ENTER will return the display to the original condition with Local time
now displaying the entered value.
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D. Blank Mode
This mode is used to set the brightness of the LCD backlighting.
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1. Adjust Brightness
Pressing ENTER in the blank mode will cause the "Set Brightness"
message to appear. Pressing the PREV key will make the display backlight brighter,
while pressing the NEXT key will make the backlight dimmer. There
are 16 levels of brightness available. After the lighting has been adjusted
for the best viewing, press MODE to exit this function.
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