DON’T RTFM
Pilot fish’s Army job is maintenance of electronic equipment, including a transmitter. Because his unit had been one of the original deployment sites for that transmitter, all of its operators have either gotten training from the manufacturer or learned from those who did.
That probably explains why the unit has only minor problems with its transmitter, whereas some others have troubles like failure of the final amplifier tube.
Because that tube is a very expensive item, a senior operator and fish are assigned to visit one of the problem units and see if they can figure out what the problem is. Once there, fish’s colleague observes the operators for a while and then tells fish that they’re doing something very backward to what fish’s unit has been doing.