Vixen SS2K question
Posted 19 May 2013 - 03:57 AM
I have an opportunity to buy a GPDX with a much desired (for me!) tall pillar. But i do not need goto as a planetary visual observer. The mount is in great order.
I know nothing about the SS2K system.
Posted 19 May 2013 - 10:44 AM
Posted 20 May 2013 - 12:12 AM
One thing though, iirc, may apply to the non-PC version or earlier ROM version, the motors are known to 'cog' when tracking, causing a jitter at the eyepiece at high powers. When I had the SS2K on my SP mount, I didn't view much above 150x, and did not notice this cogging. You might want to take that into consideration.
Posted 20 May 2013 - 12:34 AM
The nice thing about the SS2K (which is missing from other mounts, even the latest ones iirc) is that you can choose between aligned and un-aligned EQ mode. In aligned mode, only the RA motor will run to track - so you PA has to be good. In un-aligned mode, you can be pointed many degrees away from celestial pole, and once you enter the alignment stars, it will track and object with BOTH RA and DEC motors - think of it like a tracking alt-az that's pointed at a crazy angle. The mount will not only model the offset, but iirc from the manual, as you add more alignment stars, it will model other errors such as cone and OTA offset - pretty nifty.
Better yet, those modes serve as an extremely effective polar alignment aid. Do a star alignment in unaligned EQ mode (including stars from both sides of meridian), center a star, and switch to aligned EQ mode. The mount will move so that it would point at the star if correctly polar aligned. Then recenter the star by adjusting the mount's az and el bolts. All done. It's just like Celestron's ASPA but a couple of decades earlier.