Q6 Antenna Structure

The first shipment of Gemini equipment - included the FPQ-6 antenna pedestal its heaviest item - arrived in November 1966 and was transported to Carnarvon. An 80-ton crane - the largest vehicle then to have used the North West Coastal Highway - travelled north to lift the pedestal into position.

As befitting a precision instrument, the Azimuth-Elevation antenna structure and 8.8m (29ft) parabolic dish was erected upon a specially designed rigid foundation; a thick concrete base which had been poured onto several foundation piles driven 10 metres into one ancient sand dune on Browns Range.

A NASA Technical Information Bulletin announcing the imminent construction stated:
“The antenna pedestal is a precision, two-axis mount, using hydrostatic bearing in azimuth and phase roller bearings in elevation to provide mobility and support to the counter-balanced, solid-surface antenna. The antenna is positioned through anti-backlash dual-drive pedestal gearing via a high torque-to-inertia electro-hydraulic valve motor system. … A viscous coupler located between the valve motor and pedestal drive gearing damped out undesired mechanical resonances.” [1]

Put simply, the whole 30-ton pedestal, plus the dish, floated and rotated on a thin film of hydraulic oil that covered the shallow dome beneath it, which in turn sat atop the huge mass of concrete.

Reference:

[1] Technical Information Bulletin, GSFC, MSFN: Vol.1 No.11; July 26, 1963