[Amps] Fan Noise in GS-35b Amplifiers

[peter chadwick]

Low audio noise means a big blower running slowly. There was an old professional tx with 16 4CX250B in a distributed amplifier (cabinet 7 foot high, 2 feet wide and 3 feet deep!) that had an external blower which was about 3 feet in diameter and 2 or so feet wide, driven by a 3 phase motor at about 750 or so rpm. That was quiet enough that you could hear the hiss of the air leaking out of the cabinet, but that was a very big blower.

73

Peter G3RZP