Common Problems with Alignment on the NexStar
GT
Telescopes
This list summarizes several potential problems that can prevent you from aligning your
NexStar 60/76/80/102/114/4/130. Additionally, be sure to download a copy of the
NexStar Alignment Guide so that you can not
only get an alignment, but you can get a good alignment.
- Insure you are using a reliable power source for your scope - click
here
for more details.
- Your scope might be mounted backwards in the tube ring (does not apply
to the NexStar 4 GT). The tube ring
should be oriented such that the bolt that holds it closed is on the top. Then, when
facing the side where the hand control cable attaches to the fork arm, the front of the
optical tube should be pointed to the right. Note that on the N76/114/130, the front of the
optical tube is the end with the opening. Refer to your manual; the pictures are
correct, even if it didn't come that way from the factory!
- The hand control may have the wrong model selected. Incorrectly
setting the model will result in the scope missing the alignment stars
by a significant, but consistent amount. Then after you
manually center the stars, all GoTos will miss by a significant but
consistent amount. Even if you go back to one of the alignment
stars the scope will miss. If this sounds like your scope,
the model may be set incorrectly.
- With all but the "original" GT hand control (see the next bullet for
that older model),
press the
Menu button, select Utilities, and scroll to Select
Model and press Enter. Scroll up or down to display the
correct model and press Enter.
- If you own the original GT hand control (easiest to identify by the lack of a
Quick Align option), do not select the model of scope
from the menu in the GT control. If you do your scope cannot be aligned properly.
To correctly set the model of scope, simply access the
menu, scroll up to Model Select, choose Custom and enter
the correct encoder numbers for both "AZM" and "ALT". Enter
0726559
for the NexStar 60 and 80. Enter 1059334 for the NexStar 114 and 4.
Again, note that this only applies to the old GT hand control
without the Two Star and Quick Alignment options.
- If you have the original GT hand control, do not store and use locations
(longitude/latitude) if you are in the Eastern Hemisphere - Europe, Asia, Australia,
etc. There is a problem with the original GT control that prevents using stored locations
with an east latitude.
- Be sure you are entering the date in mm/dd/yy format.
- If you have the original GT hand control, don't bother using military (24 hour) time,
you must still set PM/AM anyway. With any NexStar scope, if you are aligning after midnight, entering 0130
will still require you to change the PM to AM.
- Watch for double key entries - they are common with the original GT
control and can
cause problems, particularly when entering longitude and latitude.
- If you are not in North America, you will need to select a time zone. In the
original GT control, these are not the usual offset from UTC (GMT), but instead you
should refer to the time zone charts in the manual (24 - offset from UTC).
- If you are new to astronomy, it will be important that your scope points accurately to
the two alignments stars, otherwise you might center on an incorrect star. To assure
accurate pointing during auto-alignment, level the tripod (use a small level in the
accessory tray), then point at Polaris (the North Star), then lower the optical tube to
the level position (it is best to use a set of marks as described in the
NexStar Alignment Guide). Click
here for a table and all-sky chart of the 40
NexStar alignment stars so that you won't be fooled by an incorrect star.
- Occasionally the alignment procedure will be completely off-track. If your scope
doesn't point anywhere near what you think is the correct star, you are best off pulling
the plug and starting over.
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