New telescope decision

Dave - the raw data shows some fairly hefty spikes of as much as 4 arcseconds or so. But the averaged curve looks good - 6 to 7 arcsec peak to peak.

I'd say that was the seeing. Also I used vega probably not the best star to use for a PE test.

Did you have to tell the software your resolution, pixel size etc? And is the chart dervived from you main OTA or guidescope?

Yes the image scale parameters were set in guidemaster. This was done through the main scope.

As far as sidereal rate goes, I suppose if it was inaccurate that could cause 'drift'. But in the case of the graph below, I'd suspect other issues first - polar alignemnt, mirror flop etc.

Yes of course it could be any of them. Some more tests will tell for sure. Still I'm very happy with 6-7" without PEC. I did a very rough PEC training after I took that data. With PEC running the results never strayed outside 3" PTP and rarely went outside 2". Pretty amazing performance for a mass produced mount!

Dave --

Interesting hockey-stick effect (the drift appears to accelerate as time goes by).

If I remember correctly, this is the same effect you see while drift aligning which might (?) suggest that it's the result of a slight polar misalignment.

-- Jeff.

Dave Lillis wrote:

John O'Mahony wrote: it is an AC synchronous motor operating at 220V. I had tried Meade (no joy) and one or two specialist shops who recommended a new mount for the OTA.
John

I'm surprised that the actual motor runs on 220 AC and isnt stepped down to some dc voltage in the base of the scope, if it were, it would be very simple to get it working for the northern hemisphere.
I've had a look on the web and see that the LX5 2080 has a north/south switch on the base control panel, does your scope not have this ???
www.grampianstars.com.au/telescope.htm
or is your scope pre 1987 ??

Hi Dave
The 2080 was bought in '93 but it was one of the last 2080 scts that Meade were producing (and it was all I could afford at the time-the LX3 at that time was too pricey). It has no switches on it to reverse direction. The advice I was given was to remove the OTA and put it on a new mount. To be honest, I have never been comfortable with 220V out in the field especially when the scope must be connected to earth.
regards
John

I wouldn't be happy with that either, you're definitely making the right decision ditching the mount.

The telescope has now been ordered (CGE 11) No going back now! (with the weather we have been having recently one would wonder if it was worth it).
Looking forward to the day it arrives-hopefully with clear skies !!

John O'Mahony

The telescope has now been ordered (CGE 11) No going back now! (with the weather we have been having recently one would wonder if it was worth it).
Looking forward to the day it arrives-hopefully with clear skies !!

John O'Mahony

You know on the sliding scale a CGE 11 is worth at least 6 months of cloud!!

You made a good decision John. The CGE11 will deliver. You've now got a very powerful scope on a great mount. The thing about the cloudy skies is when your sitting inside looking at it you wonder why you bothered in the first place. Then when you get a great night you know exactly why you did!

Best of luck with it.