AUTOSTAR INFORMATION Last updated: 23 August 2000

Autostar Altitude/Azimuth HOME Position

Subject:	 Alt Az mode
Sent:	Monday, August 21, 2000 18:32:49
From:	rickieweiss@worldnet.att.net (Rick Weiss)
My ETX 125 tracks well enough in Alt/Az mode with my Autostar. However
I'm uncertain that I've set it properly for the Alt/Az home position. 
My scope has tried to go beyond the stops while slewing to some objects.

Could you review the procedure for putting the scope into the Alt/Az
home position?  Please include the orientation of the scope relative to
the tripod (scope base to the "N" leg).  Also, when turning the scope
counter-clockwise then clockwise until the fork arm is above the
controller, how much does the scope need to be rotated to achieve this?
(a quarter turn, one and a quarter turns?)

Keep in mind that I do get a successful alignment, but it wants to slew
past the stops while moving to some objects, which leads me to believe
that I do not have the scope orientated correctly.  Meade's instructions
are less then stellar in this area.

Added later:

I looked for the information you suggested.  I still don't know how much
the scope needs to be rotated (actually amount, not the location)once
the counter-clockwise movement is done.  I need to rotate mine almost a
full rotation to get the fork arm lined up with the controller and still
have the scope facing forward.  Is this correct?

Again, my problem is that the scope tends to hit the stops while slewing
sometimes.

Any help you can give is greatly appreciated.

Rick

1. Position the whole ETX and tripod system with the ETX control panel on the west side. This doesn't have to be exactly due West but should be as close as possible.

2. Level the ETX base. Again, this doesn't have to be exactly level (I usually just eyeball this).

3. Unlock the altitude axis and position the ETX Optical Tube Assembly (OTA) to 0 degrees. The ETX OTA should be parallel to the ETX base. Relock the axis. If the scale is off it can be adjusted by loosening the knob, rotating the scale, and retightening the knob.

4. Loosen the azimuth lever and rotate the ETX OTA counterclockwise until you hit the stop. Counterclockwise means moving it from (for example) South to East to North to West.

5. Now rotate the ETX OTA clockwise back to the North. This is a rotation of approximately 120 degrees or from pointing towards the Southwest through West to North.

6. Continue with the Autostar Alt/Az initialization and alignment.

Return to the top of this page.

Go back to the Autostar Information page.

Go back to the ETX Home Page.