GSO - 12" f/5 Dobsonian GSD 980 - 300 mm aperture  - 1500 mm focal length

The Dobsonian with high "Deep Sky performance"

Join the growing mumber of happy users of GSO quality telescopes! The large 12" Dobsonian is a impressive telescope, not only due of his powerful mirror, it´s really large. The telescope is too large for the backseats of the most cars, so you need a station wagon because the tube has a length of 145 cm.

At the night sky the GSD 980 shows an impressive performance. So you can observe every object of the NGC catalog. You can see so many objects in Virgo that you can observe many nights and you won´t see objects twice!

Optical Quality
The centerpiece of any telescope is its optics. GSO produces parabolic primary mirrors of very high quality. It is our firm opinion that GSO offers better mirrors than typical in this price range. We guarantee a diffraction-limited performance, which essentially means that the performance is limited by observing conditions and the laws of physics rather than by the telescope itself!

2" Crayford Focuser
This is one of the best focuser this manufacturer has to offer. It is far superior to most classic rack-and-pinion focusers:

• no image shift when focusing
• large load capacity: Up to approx. 3kgs with a firm friction setting
• 1:10 dual speed microfocuser for far improved focusing precision
• compression rings for 2" and 1.25" accessories

New Altitude Tension
On most Dobsonian telescopes the altitude bearing is a very simple design. GSO has developed an improved altitude bearing with additional functionality: A strong steel shaft bears the weight of the tube. The tube is guided and kept in position through two CNC machined surfaces. The desired tension can be freely adjusted with a large knurled knob on both sides. This is particularly helpful when changing eyepieces where the telescope is temporarily out of balance.

Balancing System
This is another major improvement of this bearing system. The telescope can be balanced by moving it up or down a couple of centimetres. This may be necessary when adding a second finderscope (e.g. a Telrad) or when using very heavy eyepieces or a binoviewer. A scale on both sides allows you to easily achieve a symmetric bearing position.

Azimuth Roller Bearing
The new GSO Dobsonians have a modern industrial roller bearing for a very easy movement. Metal plates above and below the bearing prevent the rollers from sinking into the softer wood of the rocker box, so the movement will remain smooth even after years of use.

Delivery contains

• GSO Dobsonian Telescope
• Fan behind the main mirror
• 8x50 Finder with achromatic optic
• 2" Crayford focuser - 1:10 micro - reduction from 2" to 1.25"
• 30mm 2" Wide Angle ERFLE with 70° field for good overfiew
• 9mm Super Plössl - multicoated
• 2" 35mm extension tube
• eyepiece and accessory tray for eyepieces and filters
• Collimation manual