Dobson GSO Deluxe 250/1250 with closed tube and wooden base

Dobson GSO Deluxe 250/1250 with closed tube and wooden base

DESCRIPTION

The GSO Deluxe 250/1250 Dobsonian offers a practical balance of portability and optical performance. It features a 250 mm parabolic primary mirror in BK7 glass with a 1250 mm focal length (f/5). The secondary mirror is fixed to a rigid metal holder that ensures stability and avoids detachment with temperature changes. Its optical coating provides 94% reflectivity, and the design offers excellent contrast with low central obstruction (25%) and thin spider vanes.

The 2" Crayford focuser with 1:10 micro-reduction enables smooth, precise focusing, even with heavy accessories up to 3 kg. It accepts both 2" and 1.25" eyepieces or coma correctors via compression rings.

The wooden Dobsonian mount provides smooth motion in both axes, enhanced in azimuth by roller bearings for better tracking than typical Teflon pads. Altitude resistance is adjustable via two side knurled knobs. The balance system allows the tube to be shifted back or forth to compensate for additional accessories like binocular viewers or finders. Dual side scales help ensure symmetrical alignment.

The closed optical tube rests on a sturdy wooden base. A multicoated 8x50 optical finder and two eyepieces are included: a 9 mm Plössl (1.25") and a 30 mm Erfle wide-angle (2", 70°).

TECHNICAL SPECIFICATIONS

Aperture: 250 mm
Focal length: 1250 mm (f/5)
Primary mirror: BK7 parabolic
Theoretical resolution: 0.5"
Central obstruction: 25%
Tube diameter: 305 mm
Tube length: 1210 mm
Tube weight: 15.5 kg
Mount: Dobsonian wood base
Mount dimensions: 64 cm (height) x 54 cm (diameter)
Mount weight: 12.2 kg
Focuser: 2" Crayford with 1:10 micro-fine adjustment
Included accessories:

• Multicoated 8x50 optical finder

• 9 mm Plössl eyepiece (1.25")

• 30 mm Erfle eyepiece (2", 70°)