John Bubb


Exciters, Transmitters and Heat Exchangers


Unfortunately I did not take pictures of all these units. As I recall the heat exchangers and transmitters were about the same size— 6 to 8 feet wide by 6 feet high by 5 feet deep. Heat exchangers were not very exciting in appearance. The transmitters contained four tuning handles connected to the klystron tuning cavities and power output meters which helped us tune for peak power.


Exciters (Ex)


My memory does not serve me well regarding these devices. They were in the form of modulators and amplifiers which drove the klystron transmitters. Possibly another technician can fill in my memory blank.

Transmitters (Tx)


The transmitters each contained a high-voltage power supply and one very large Klystron tube. The Klystron was about 4 feet high and had four external tuning cavities that fit around the tube with clips and were tuned by mechanical linkages to the front panel. The whole Klystron assembly was on a wheeled carriage and we maintained one spare carriage at each end of the building for rapid emergency replacement. Klystrons were cooled with a water and antifreeze mixture. The heated mixture in turn was cooled by a heat exchanger unit.

Just before I arrived on site at Saglek, one of the transmitters had suffered a critical malfunction. I remember Rory Doherty our site supervisor telling me the story of the concerned efforts to keep the remaining transmitter running until parts could be flown in to repair the malfunctioning unit. Recently (2006) I made contact with Roger Mugford who was involved in that incident. His report, used with his permission, can be read by clicking Here.

Heat Exchanger (HE)


There was one heat exchanger for each transmitter. The water and antifreeze mixture was passed through a radiator-like grille over which cool air from outside was drawn by a large fan. The cooled mixture was returned to the transmitter in a closed loop. One of our most unpleasant duties was to clean the inside of these units. It was very cold and very dirty work—and usually assigned to the most junior employee on shift.

The following picture shows the exciters in the foreground and a transmitter in the back. The copper pipes above the transmitter carried the antifreeze cooling mixture from the heat exchanger.