Heq5 tracking

[mgirdwood]

Hi - I am having a few problems with the 3star alignment and a lot of good help is appreciated on that thread. (leveled , compass north, latitude ). Using BEOS.

So I tried a 2star align to see if anything was working correctly on the mount.

Although it seemed to be okay, when I went goto to M51 it was only just at the bottom of the frame which was a little. Any way the idea was to check how long the mount would give me before the trails were just to bad. On the handset set tracking to sidereal and waited a little.

With my SW102 goto I am getting up to around 25secs before it all goes wrong. So I was expecting somewhat better from the heq5. Nope , even at 15 secs stars were trailing very obviously.

Am I just being thick ? Did I miss a step on the handset because it definetely doesn't appear to be tracking. Any ideas ?

[Capricorn]

One thought is the 102 is aligned by looking throgh the scope, the HEQ5 is aligned by looking through the polar scope. You don't actually need a scope to align the mount.

Actually you are aligning the mount not the scope and it can be an easy error.

Compass North is not True North - think 4 to 6 degrees different, so there is a few degrees of error there. That is the most obvious. You have a polar scope to set polaris up.

After that come the good old DST or not DST. Presently DST is On/True/Yes.

[mgirdwood]

Thanks for the reply Capricorn, I don't have a sight line to north so that isn't possible, one of the reasons I was trying in my other thread to use the latest beta with software polar align. - no joy so reverted back to ver 3.27

With the 102 her is no polar just rough north and a 2 star align and yet I am able to get 25 secs of good photography - hence my real suprse ar no photography . I wonder if the tracking isnt running properly.

[JamesM]

The 3 star alignment procedure is of course in addition to the accuracy of the polar alignment itself and might in part explain why a chosen object is not in the middle of the field. To help with the accuracy of the 3-star procedure, when you agree to the nomination of the first star, allow the mount to go travel to its location but rather than make the necessary final adjustments via the handset, disconnect the RA and DEC clutches and move the scope manually to the first star and then re-engage them when this has been done. After that, you can reposition the scope for the 2nd and 3rd stars using the handset. One other thing I have found, is that for me, there is often a delay between dialling in the correct time on the mount the time of my polar aligning and the time I input into the handset when I finally start my three star alignment after attaching and balancing the scope. A lot of people are able to attach all their gear first before polar alignment and therefore minimising this delay, but if you have a heavy scope, that's not always possible and might explain why the scope is just off of target. I'm not aware of ever having to select the rate of tracking at any point (apart from slew speeds when locating alignment stars) and assume the hand controller is set to sidereal time by default or that it chooses this because the system knows that I am observing at night due to date and time. I notice from this page in the synscan manual that it is possible to amend the autoguide speed (bottom of the page) and whether this might be applicable to you and the kit you use to image.

It might be a good idea to copy this question over on the imaging section to see what response you might have there as I am sure this problem is quite common and not a reflection of your ability to follow instructions.

James