AP 600E Polar Alignment Question
Jim Fakatselis <jfakatse@...>
Thought I'd pose a question to the group.
My AP 600EGTO hand controller has version 2.2 and my manual is dated
11/2/98. Method 1 suggests a star greater than +/- 4 hrs RA from the
pole Why in the first method of polar alignment does the manual state
that Arcturus is not a good star for aligning since it is too close to
Polaris in RA? Polaris has an RA around 2 H, Arcturus is around 15 H,
what am I missing?
Also, are the upgrades to the servo box and hand controller going to be
available soon? I can't wait.
Would anyone volunteer any method to get a closer polar alignment
besides Method 1? Every time I try to align and try to refine via an
additional iteration as stated in the manual, it doesn't get much
better. Can anyone help?
I have read Roland's modified method but I need to get past Method 1 and
get close before I refine.
Thanks in advance,
Jim Fakatselis wrote:
Thought I'd pose a question to the group.Jim,
You didn't say whether you were having trouble with tracking or with pointing.
If it's pointing, you may also want to look at the orthogonality of your setup.
I use method 1 (N-Polar calibrate) exclusively, and ususally end up with only
2-3 sec. of drift in either axis over a 10 minute period. This is ok for me since
I am using either the T&A or self-guided modes of the ST7. Here is a track list
from my 10 min. T&A run on NGC 6946 last week. Pixel scale is 1 sec. per
pixel. The first column is DEC and the second column is RA. I had used Deneb
for alignment, and iterated about 5 times.
Version = 1
Snapshots = 20
Snapshot_time = 30.00
Temperature = -4.82
Height = 510
Width = 765
Offset = 0
I don't know the answer to the Arcturus puzzle, except that Arcturus doesn't
work well for me either, so I avoid it. Perhaps it is because Arcturus is almost
exactly 12 hours in RA from Polaris.
As for iterating, this works great for me and the more iterations I do the better
the alignment gets. Charles S. has suggested iterating on one star until it's good
then picking a second star on the other side and re-running the N-Polar alignment
procedure using the second star.
Derek Wong <dawong@...>
Method 1 suggests a star greater than +/- 4 hrs RA from thePerhaps Charles could comment, but I think what the manual should state
is that the best alignment stars should be 4-8 hr. RA from the pole,
preferably at declinations below 0. Arcturus is nearly opposite Polaris
(close to 12 hrs. away) and would take several iterations to work
Previously, Charles indicated that a new two star alignement would be
available which sounds very promising.
Would anyone volunteer any method to get a closer polar alignmentGet the polar alignement scope--it's the easiest way.
Also, check your orthogonality.
Get the polar alignement scope--it's the easiest way.Hi Derek,
I have the polar alignment scope but I have not installed it yet. I
understand that it first needs to be aligned coaxial with the RA axis
then it can be usedproperly. Any tips on getting it coaxial? I have a
lot of trees in my back yard and can't sight a far away HV insulator.
Could it be aligned at night?
Also seems confusing on the polar reticle. What stars correspond to the
reticle marks? It's not clear from the documentation.
Thanks for your assistance.
Derek Wong <dawong@...>
I have the polar alignment scope but I have not installed it yet. IThere should be some instructions, and I poseted my thoughts on message
#2 of this e-group.
I have aI think it would be very difficult. Perhaps you can set up during the
day in front of your house just to align the scope--then you could sight
something far away.
Also seems confusing on the polar reticle. What stars correspond to theIf you look at a map, it is confusing. Alpha, Delta, and Beta
correspond to Polaris, Delta Ursae Minoris, and Beta Ursae Minoris
(sorry, I forgot their common names). When you look through the scope,
turn the axes so that Polaris and Delta are in their respective
circles. The dashed line will point toward Beta, which is out of the
If you look at a map, the angles don't match--the reason is that the
polar scope is a refractor and the image is reversed. Since you are
looking at the Alpha-Delta line directly through the scope and the
Alpha-Beta line naked eye, this illusion is created.
Anyway, good luck--my illuminator just went out, so no polar alignment
What can i do to verify orthogonality.I have a C8 and a ap900 gto and
i have some problems with the precisions of pointing of the mount.
When i press Rcal to recalibrate on a star (for exemple deneb) then i
can slew to another star (for exemple polaris).Polaris is away of the
center of the ocular.If i press Rcal 3,4 or 5 times (with different
star) on the same night then i slew to polaris,i can't see polaris
with the ocular:the precision is decreasing!!!
What's wrong,orthogonality or else?
Is the horizontality important with the polar alignement scope?
Charles Sinsofsky <strfire@...>
The polar alignment routine using 4 stars ie: using the n-polar aligmenttoggle quoted messageShow quoted text
mode with at least 2.4 firmware will not require you to move the scope by
hand anytime, other then the inital pointing, but will permit you to get
VERY accurate polar alignment. I have done 35 mins unguided prime photos
with my 1200 using my polar aligmnent routiens with 4 stars and medium to
high power eyepiece., I use deneb, vega, arturaus, and sometimes a variety
of stars for the fourth one. remember the key here is repetition, ie: go
back and forth between the selected star and then the next and the next, and
then start al over again, I do the whole sequenece oin this form. first star
choosen 4 times back and forth from polaris autoslewing and thne second star
4 times etc... and then I do this same to all the way to the 4th star or 3rd
star and then I start all over again with ther orignal 1st star. I do this
proces 3 times, by the third iteration the stars always fall dead center all
the time. perfect polar alignment.
----- Original Message -----
From: Derek Wong <email@example.com>
Sent: Sunday, September 19, 1999 8:12 PM
Subject: [ap-gto] Re: AP 600E Polar Alignment Question
Hi Jim:Method 1 suggests a star greater than +/- 4 hrs RA from thePerhaps Charles could comment, but I think what the manual should state
HelloRegarding orthogonality, there's a bit in the GTE manual on it--p. 21 in mine.What can i do to verify orthogonality.I have a C8 and a ap900 gto and