Reflector: Paraboloid diameter: 140 feet. Surface: 1/8 inch aluminum plate. Surface tolerance: 0.030 inches at zenith. Contains: 350 tons of aluminum, 35 tons of concrete ballast, 5 tons of balancing blocks. Focus: 60 feet above the surface. Carries 1/2 tons of receiving equipment. Position relative to paraboloid stable to 1/4 of an inch. Declination Axis Shaft: Length: 67-1/2 feet overall; 57 feet between bearings. Diameter: 2 feet. Material: composite aluminum and steel shaft running in two spherical roller bearings. Rotates 145degrees to -53degrees north of zenith and 92 degrees south. Yoke: Serves to support the declination shaft and to rotate the antenna east and west about the polar axis by means of the polar gear. Polar axis Shaft: Length: 67 feet. Diameter: 12 feet. Weight: 555 tons of steel; 170 tons of high density concrete ballast. Rotates 220degrees -110degrees east of meridian and 110degrees west. Gear Sectors: Diameter of polar sector: 84 feet. Diameter of declination sector: 71 feet. Spherical Bearing: Diameter: 17-1/2 feet. Surface tolerance: 0.003 inches. Floats on oil film 0.005 inches thick. Base: Height: 60 feet; 41 feet 6 inches to observation deck. Contains: 5700 tons of concrete and 140 tons of steel. Wall thickness: 3 feet. Houses control room, hydraulic and electric equipment, transformer vault, and electronic workshop. Total Moving Weight: About 2,500 tons. Mount: Equatorial - Two mutually perpendicular axes. Pointing Precision: 10 arc seconds - about the diameter of a dime at 400 yards. Research Program: Studies of known element and molecular spectral lines. Continuim research at other than line frequencies. Generally at wavelenghts between 2 and 40 cm. Very-long base interferometry (VLB) using the 140-foot and non-NRAO telescopes. Date of Completion: Spring, 1965