Another AP1200GTO mount!

Bye Bye CGEs!

The era of the Celestron CGE mounts here at Beverly Hills Observatory are numbered.  Yesterday I purchased another previously-owned Astro-Physics 1200GTO mount, to be used for the photometric telescope in the North Dome.  As soon as the pier adapter plate arrives I’ll be retiring the CGE and will put it, and the one I removed from the South Dome, up for sale on AstroMart.  Both mounts have served very very well for eight years.  Each mount has all the usual foibles so familiar to other CGE users.  Yet every single bit of data and every image and spectrum, save for spectra gathered in the past year, has been acquired using a CGE.  For the money you just can’t beat ’em!


Figure 1: M3 taken with one of the C14 telescopes using a CGE mount. Not bad considering the image scale of 0.72 arc-seconds per pixel.

Figure 1 is an image I took one evening of the globular cluster M3, combined from 12 2-minute subexposures.   Given the image scale of about 0.72 arcseconds per pixel the star images are nice and round, indicating solid guiding.  If you ask many imaging experts they will tell you the CGE is not up to handling a 14-inch Celestron at full imaging scale and I would largely agree with them, particularly for objects near the celestial equator.  But that’s from an imaging perspective where one is trying to get the perfect “pretty picture”, where nice round and tiny star images is paramount (pun intended all you Bisque fans).  But for photometry it just isn’t as important if a few images out of a multi-hundred image sequence is trailed.  It does negatively impact the signal-to-noise for measurements in trailed images, but I was willing to sacrifice a few images until I could afford something better – and that time has come!

Hello AP1200s!

Last year I acquired a 1200GTO mount for the South Dome and, after a whole bunch of issues with the motors and encoders (essentially both motors and encoder assemblies had to be replaced) the mount has performed brilliantly.  Furthermore, the support I received in determining the source of the problem and making the necessary repairs was surely beyond anything I’d experienced.  The first AP1200 I purchased was, as far as I could determine, 12 years old, thus well out of warranty.  Furthermore, Astro-Physics doesn’t even manufacture the mount any longer (so it’s a “legacy” product).  They surely were under no obligation to go to the lengths they went to in order to get the mount working.  After their expert repairs had been made the AP1200 in the South Dome has performed flawlessly.  Both the build-quality and product support convinced me that I never had to look elsewhere for a telescope mount; I’m an A-P customer for life!

The first AP1200 installed in the South Dome.

The first AP1200 installed in the South Dome.


In the past year Astro-Physics has released two new mounts to their lineup and one, the AP1100, looked to be the perfect match for the C14 telescope.  It weighs a bit less than the 1200 but has about the same carrying capacity as the older AP1200.  Both were well above what I need for a C14.  But a week ago I spotted another AP1200 for a nice price on AstroMart.  This mount came with lots of the accessories that I would have had to purchase individually, as well as a “portable” pier that would allow me to take one of the telescopes out for dark-sky viewing (whatever that is).  Yesterday I drove to Ashland, VA to meet the seller and after a quick listen to the motors paid the man his asking price and brought the mount home.  Over the next week or so I’ll take it apart to check it out, maybe clean and re-grease the gears, but by all appearances this mount is in perfect working order.  It will be installed as soon as the pier adapter plate (which attaches the mount to the concrete pillar) arrives from Dan’s Peir Top Plates (another very much recommended company, by the way!)


Here’s then “new” AP1200 on it’s “portable” pier. The pier is really too high for my purposes, but I may keep it for the times I might pack up and go to observe somewhere with darker skies. Everything checks out so far; over the next few days I’ll look at the gearboxes and worm wheels to see if they need to be cleaned and re-greased.


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