Digital Setting Circles vs Goto Accuracy


Brian <brian@...>
 

Hey Group,
I have an AP400GOTO and a 1200 QMD with NGC max and setting circles.
The dscs are 4000 tic encoders. If I take a little extra time to
align carefully using a 150x EP and level the mount (1200) I can get
the object in the FOV of the 150x EP.
Last night in using the 400goto I noticed it dead centers the object
after a careful polar reiteration and leveling of the mount.
Question is how many "tics" or what is the comparative accuracy of
the two? Does goto have 12000 tic or 24000 tic or the same 4000 tic?
an enquiring mind wants to know.
thanks
Brian


Larry Denmark <kldenmark@...>
 

Hi Brian,

I can't answer the specifics in your question, but the best pointing
accuracy you can get with 4,000 tic encoders is 324 arc seconds (360
degrees x 60 min. x 60 sec. / 4,000). The GTO mounts form AP have the
encoder mechanism built into the motors (I think) and give an accuracy
of 0.2 arc seconds.

Larry

E-mail . . . kldenmark@...
Web site . . http://home.att.net/~kldenmark/


Hey Group,
I have an AP400GOTO and a 1200 QMD with NGC max and setting circles.
The dscs are 4000 tic encoders. If I take a little extra time to
align carefully using a 150x EP and level the mount (1200) I can get
the object in the FOV of the 150x EP.
Last night in using the 400goto I noticed it dead centers the object
after a careful polar reiteration and leveling of the mount.
Question is how many "tics" or what is the comparative accuracy of
the two? Does goto have 12000 tic or 24000 tic or the same 4000
tic?
an enquiring mind wants to know.
thanks
Brian