I was in contact with Allan Weiner July 28.
He tells me that a new TH576 tube has been ordered from Thales in 
France. He did not confirm whether the failed tube was under warranty. 
Delivery is expected in 4 weeks.
Regarding 9330 - he states that for now a small back-up transmitter is 
coupled directly to the Ampegon antenna.  Allan did not answer my 
question regarding
its location or output power.  I guess it might be 5 kW or even less and 
it is probably situated in the base of the antenna tower. It can't have 
been an easy job to connect the wiring and feeder lines. I think the big 
antenna is pointed in only one direction (270 degrees?) for the moment, 
until the 500 kW is back on air and everything is computer controlled again.
(Alan Holder G4ZBH via WOR io group)