After reading about the twin dishes proposed for Jamesburg in an earlier article about Jamesburg Earth Station in the US, Tony Fisher wrote back with this story:
I wonder if the 100ft Ceduna 1 dish was also specified for this capability? It had a tracking speed of an incredible 0.3 degrees per second in both Azimuth and Elevation, although I only ever once saw it run in “full flight”, and then quite by accident. I always understood this was to enable the dish to track launches coming over the eastern horizon, as back when it was built, Ceduna was the first ground station to be able to communicate with the launch vehicles as they came back into radio contact having passed through the atmosphere.
Harking back to my “accidental” full speed operation of the double drive motors, – during my early days at Ceduna, as a TO1 and still quite fresh out of training, – Ceduna 1 had a very rare “out of service period” just after the 30m Ceduna 2 facility was brought online. I was given the task of the full “service book” maintenance routine on the Ceduna 1 Synchro Resolver Manual Control Panel, which I diligently set about at the start of my maintenance day shift. Unfortunately I forgot to manually lock the brakes on.
End result, with a gently breeze running throughout the day, the dish was gently “blown around towards the POR”, in stark contrast to where it should have been – on the IOR. Towards the end of my shift I was initially quite pleased with myself, having got through the massive task of dismantling, cleaning and re-assembling all the “clockwork” components of the synchro resolvers and the manual control wheels, getting everything back together in the precise “pointing” position, – ready to put the large synchro resolver chassis back into the rack and “plug it back in”. Going around the end of the control room rack suite however to reconnect the myriad of massive Cannon connectors, I glanced out the window where, – to my horror I saw the 100ft dish “pointing” the other direction.
Now I had a problem! What was going to happen if I plugged the syncro resolver antenna position controller back in? I figured one of 3 things.
- Emission of “Grey electrons”, – hmmm quite possible.
- A screaming rotation of the syncho resolvers in the controller to bring it back into alignment with the actual position of the dish, or
- Maybe, just maybe, the antenna would drive back to align with the controller.
End of shift! What to do? Nothing ventured, nothing gained! Plug it in!
Every-one stood around to watch me suffer under utter humiliation. No-one breathed while I plugged it in and switched the power back on, – but to everyone’s amazement, None the least my own, the dish motors arced up to full speed and literally screamed. Much to my relief, – the Ceduna 1 antenna drove back to its IOR pointing location, only slowing momentarily as it converged with the synchro resolver positions and the Nixi Tube display positions in the controller. I had lived to learn another day!
Thanks to my many mentors and “associates in crime” including: “JG”, “ERW”, “BLA”, “PWB”, “PM”, “CE”, just to name a few. Those were good times indeed.