Posts Made By: Mike Shade

Anyone have any idea of the price used of an original Paramount 1100? This is not a new ME or an 1100S but the original version of this mount. I will assume condition as like new with everything working perfectly. The mount in question is I think one of the earliest ones and has seen a fair amount of use. Might have a chance to purchase but have no idea what fair price is (again assuming that it is like new and everything works as it is supposed to).

Thanks,

Mike

Well the new 1200GTO arived yesterday and I spent several happy hours last night drift polar aligning it in the observatory(I hate drift aligning). Got a reasonably good polar alignment in that there is no Dec drift in 15 minutes that I can see through the C-14 with 12mm guiding eyepiece (about 325X). This thing is attached to a pier in the observatory and I used a GPS to get Lat and Lon and one of those "atomic time" clocks to get accurate time. I used the same guiding eyepiece for initial "alignment" for the first star of the evening. The pointing accuracy was reasonably good in one half of the sky say from Vega to M57 and from there to M8 and so on. However from there to say M51 it sort of missed the target. Was near the center of the finder but not in a low power eyepiece. Moved it and synched and it was happy. Also noticed this same problem during long slews when hooked up to The Sky, crossing the meridian and so on. Once it was aligned it put things almost in the center. Thus I have a few questions:

What is the expected pointing accuracy?
How important is the "time" setting for the handpad and in The Sky (set time in handpad to the nearest minute, NOT in The Sky as it was off by perhaps three or so minutes)?
What are some tricks for improving pointing accuracy, if any?
How much influence might mirror shift/flop and that sort of thing inherent in C-14s have?
I am thinking that Tpoint might help quite a bit as I'm planning on using this thing for CCD work with a tiny chip so it needs to put things in the center of the field.
Thanks,
Mike

Well the new 1200GTO arived yesterday and I spent several happy hours last night drift polar aligning it in the observatory(I hate drift aligning). Got a reasonably good polar alignment in that there is no Dec drift in 15 minutes that I can see through the C-14 with 12mm guiding eyepiece (about 325X) and a diagonal. This thing is attached to a pier in the observatory and I used a GPS to get Lat and Lon and one of those "atomic time" clocks to get accurate time. I used the same guiding eyepiece for initial "alignment" on the first star of the evening. The pointing accuracy was reasonably good in one half of the sky say from Vega to M57 and from there to M8 and so on. However from there to say M51 it sort of missed the target. Was near the center of the finder but not in a low power eyepiece. Moved it and synched and it was happy. Also noticed this same problem during long slews when hooked up to The Sky, crossing the meridian and so on. Once it was aligned it put things almost in the center. Thus I have a few questions:

What is the expected pointing accuracy?
How important is the "time" setting for the handpad and in The Sky (set time in handpad to the nearest minute, NOT in The Sky as it was off by perhaps three or so minutes)?
What are some tricks for improving pointing accuracy, if any?
How much influence might mirror shift/flop and that sort of thing inherent in C-14s have?
I am thinking that Tpoint might help quite a bit as I'm planning on using this thing for CCD work with a tiny chip so it needs to put things in the center of the field.
Thanks,
Mike

A recent image of the little galaxy NGC7223. C-14 at f/7, ST7 binned 2x2, flat/dark/bias frame with some processing in AIP4Win. One single 30 minute exposure with scope on AP1200 GTO mount in Sonoita AZ.

A small portion of NGC 6992 through the C-14 at f/7 with the ST7 binned 2X2. A single 30 minute exposure with dark/bias/flat and some processing in AIP4Win. From Sonoita AZ, of course.

NGC 6118 with the C-14 at f/7 with the 2X2 binned ST7. Some processing in AIP4Win and dark/bias/flat corrected. One 30 minute exposure from Sonoita AZ.

Does anyone have any experience with the quality of RC optical products like tubes and mirror cells and so on? Not interested in optical quality but mechanical quality.

Also, how do they mount their primary mirrors? Center mount, mirror cells, what?

Thanks,
Mike

Does anyone have any experience with aligning a GEM (in this case an AP1200GTO) by using a CCD camera? I have done a drift alignment with a reticle eyepiece, and used Tpoint (neither of which agrees with the other). My understanding is that using a CCD camera can be very accurate. Will be using a C-14 at f/7 with an ST8E binned 3X3 in focus mode with Maxim 3+.

Interested in where to drift...did the drift alignment pointed at a dec +20 within 1 hour or meridian and then very low in the east. No drift that I could detect in 15 minutes but am getting some RA drift so might try this method.

Thanks,
Mike

Anyone have any comments/thought on the Optec .5 focal reducer? Thinking of using one on a C-14 and wonder if this would get me anything more than the Celestron one that I have now. How well does it flatten the field and how well does it mount to the ST8E?

Any comments would be great.

Thanks,

Mike

I have one of recent vintage that is not bad. Optics are reasonably good but the mirror flop/shift is annoying and the one major problem. Have run bolts through rear cell and this helps but one has to be careful or one can change collimation. Use a JMI focuser for CCD work and it is a reasonable system.

Mike