iOptron ZEQ25GT ユーザーズマニュアル

 
 

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If you’ve done with the two star alignment, press the BACK button to finish the alignment. Press 

ENTER key to select third star for further alignment. 

 

This shows Polaris position in northern hemisphere or Sigma Octantis position in southern 

hemisphere, which is used for Quick Polar Alignment. 

 

You can turn “PEC Playback On” while you do the tracking, especially for long time astro-

photography. The default status is PEC Playback Off when the mount is turned on. 

All Equatorial mounts have a small variation in the worm gears which can be corrected by using 

Period Error Correction or PEC. PEC is a system which improves the tracking accuracy of the mount by 
compensating for variations in the worm gear and is especially useful when doing astrophotography without 
autoguiding. Because the variations are regular, it is possible to record the corrections required to cancel 
out the worm gear variations and to play them back. 

In order to use the PEC function, the Go2Nova hand controller needs to record the PE first. The 

periodic error of the worm gear drive will be used to correct periodic error. The data will be lost when the 
power is turned off. 

Here’s how to use the PEC function. 

1. Setup the mount with a telescope in autoguiding condition by connecting a guiding camera to a 

computer via mount’s Guide Port or ASCOM protocol; 

2. Press MENU, select “Auto Guide” and press ENTER. Select a guiding speed from 0.20X to 

1.00X; 

3. Then press the BACK button and select “PEC Option” from the menu. Use the ▲ and ▼ scroll 

buttons to display the “Record PEC” option and press ENTER to start record the PE.  

4. It takes the worm gear 600 seconds to make one complete revolution. After 600 seconds PEC will 

automatically stop recording.  

5. The data will be lost when the power is turned off. 

 

Besides various star lists available in the hand controller --you can add, edit or delete your own user-

defined objects. You can also add your favorite observation object into the user object list for easy sky 
surfing. Up to 60 user objects can be stored here. 

To set user objects, press MENU button, from the main menu, scroll down and select “Set User 

”.  

 

Set Up Controller 
Align 
PEC Option 
Set User Objects