Support Astromart! | Log In | Help
Astronomy NewsTelescope ClassifiedsTelescope AuctionsTelescope Articles & ArticlesTelescope Articles & ReviewsTelescope and Astronomy ForumsAstronomy Events Calendar
View Categories
Browse By Location
Place A New Ad
Display Preferences
Search Classifieds

User Name:


Save Login
New to Astromart?
Register an account...

Terms of Service
Privacy Policy
Help & FAQ
Astronomy Links
User Profiles
Top Users List
RSS Feeds

Home > Classifieds > Astromart Classifieds > Mounts - Equatorial > Classified #289448

For Sale: A-P Model 800 GEM w/ Bartels Goto + extras [SOLD]

Please Log In to view the details for this classified ad.
Don't have an Astromart account? Click here to create one

I have a project which I am not going to finish, since I have abandoned my plans to get a plot on my club's property to house an observatory. The project is this mount. It's an Astro-Physics Model 800 GEM, and it has been converted to Mel Bartel's Goto system by Gototelescopes, and it uses stepper motors and a dedicated laptop to drive it. Here is what is included:

A-P Model 800: all original parts, motors, brackets (in case you want to convert back to the original Herst drive motors and no Goto)
8" dia. pier: 54" and 42" and all hardware
A-P dovetail base and matching dovetail rail, with custom aluminum mounting block to attach to Dec. assembly in place of tangent arm plate.
AstroPro GEM Table, black
A-P accessory trays for 8" pier, two of them
Encoders: Astro-Physics encoders for Model 800, can be used with or without the Goto system
Dell Latitude laptop: runs Mel's SCOPE.EXE off a 32Mb flash drive. P-II 233, I think.
Bartel's controller box: attached to the bottom of the Dell laptop
Earth Centered Universe and MG5 Microguider: planetarium software and a direct PC serial interface device for the A-P encoders
NGCMAX + wedge bracket: encoders can be plugged into this, or into the MG5
A-P 9 lb. SS counterweights: total of four
Losmandy polar alignment scope + adapter for the 800's threads.
Original A-P carry cases for Dec and RA assemblies (interior foam hacked away to accomodate Goto hardware on Dec assembly)
SBIG relay converter (used to attach guider to the original mount electronics)
All documentation and software that I have on this gear.

What works:
1. The mount slews and tracks very well. It has quite a big capacity, equal to a Model 900.
2. It's easy to align. It'd be even easier in a permanent observatory.
3. You can make a serial null modem connection between the Dell laptop and your notebook, and configure TheSky for LX200 protocol and command the Goto system that way.

What's wrong and/or needed for this setup to be fully operational:
1. Dec assembly needs to go back to Gototelescopes for adjustment or replacement of spur gear. There is too much backlash. Lenord Stage of Gototelescopes offered to do this for me gratis last year, but I didn't get to it. He also offered to replace the Dec spur gear with a quieter belt drive.
2. Software adjustments need to be finalized. I have gotten the software very close to the right parameters, but the Dec backlash issue needs fixing before the Dec axis can be adjusted properly.
3. Noise dampening. The steel pier resonates from the vibrations of the stepper motors. It's a little distracting, but software adjustments in SCOPE.EXE mitigate this. Filling the pier with sand in a permanent installation will fix it for good.
4. The original A-P hand controller has a broken toggle switch for selecting the guider port or the buttons. If the relay adapter box is not attached, the mount slews at guiding speed in Declination. A-P can repair it, or you can go to Radio Shack and get a toggle switch.
5. Handle broke off of Dec. carry case.

It really needs an observatory to house it. It's quite a big and bulky, and is a real pain to tote around in the back of the SUV and setup for observing. In a permanent observatory, it would be a great mount, easily carrying 60 lbs. or more.

Although I want to find a good home for this mount, I have to sell it as-is, with no warrantees or guarantees of any kind. But at this price, you'd be hard-pressed to find a more solid mount. I am completely open to negotiation. I just need to get it out of my house and into someone's hands who will appreciate the value it represents and put it to good use. The mount originally cost me $2300, and the Goto system was about $950. I figure $1500 is a fair starting point. Let's work out a deal.


Back to Listing

All times are in (GMT-8:00) Pacific Standard Time Zone  
Astronomy News | Telecope Classifieds | Telescope Auctions | Telescope Reviews | Telescopes | Telescope and Astronomy Forums | My Account | Help | RSS