ASTRO-PHYSICS
BRIEF HISTORY OF THE 900 GERMAN EQUATORIAL

The first 900 mount was shipped in late 1994. Each generation has undergone successive development in mechanical construction and the drive system over the years, evolving each time to meet the needs of advanced amateurs. We offer the following as a brief history and comparison of the various models.

As you read the descriptions below, keep in mind that each of the models has the potential to be upgraded in various ways, depending on the particular model. This may cause the mount to look different than it did when originally produced. If you are purchasing a used mount, obtain the serial number from the current owner. Then, call Astro-Physics to determine its actual year of production.

900HDA - 900 German Equatorial with Stepper Motors and Quartz Controller. All current and past models of our polar scope can be used. The RA and Dec axes featured a dovetail that allowed the mount to be assembled and disassembled easily without tools. The 900HDA shipped from September 1994 to September 1995.

900QMD - 900 German Equatorial with Stepper Motors and Quartz Microdrive Controller. All current and past models of our polar scope can be used. The 900QMD shipped from September 1995 to August 1998

900SMD - 900 German Equatorial with Servo Motors and Quartz Microdrive Controller. All current and past models of our polar scope can be used. We offered this mount as a low cost alternative to the GTO version, which was offered at the same time. All mechanical components were the same as the GTOCP1 model described below, however the drive system did not allow rapid slewing and go-to control. As it turned out, we sold only a few of these SMD mounts and decided to discontinue this model in favor of the GTO. SMD mounts can be upgraded to the GTO version. Please call for price and availability. The 900SMD shipped from December 1998 to April 1999.

900GTO - GTOCP1 - 900 German Equatorial with Servo Motors, GTOCP1 Control Box and Keypad. All current and past models of our polar scope can be used. This was our first go-to mount, offering the ability to control the mount with the Keypad or optional PC. In addition to the change in the drive system, other internal changes improved the overall performance. The 900GTO production run with the GTOCP1 Control Box was shipped from July 1998 to March 1999.

900GTO - GTOCP2 - 900 German Equatorial with Servo Motors, GTOCP2 Control Box and Keypad. All current and past models of our polar scope can be used. The GTOCP2 Control Box was more compact and a Y-Cable was used rather than separate RA and Dec cables. The 900GTO with a GTOCP2 control Box was shipped from July 1999 to October 2003.

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This page was last modified: July 14, 2009

Astro-Physics, Inc.
11250 Forest Hills Road, Rockford, IL  61115, U.S.A.
Phone: 815-282-1513   Fax: 815-282-9847