Circuit for feeding test signal into hydrophone output amplifier in underwater receiving antenna, has signal lines for test signals provided with electronic switch with attenuator at output

摘要

A low resistance signal source (20) generates test signals. Two signal lines (21,22) are connected at high resistance to one of the two inputs of respective charge amplifiers (13,14), the inputs being connected to the hydrophone (10). One signal line carries the test signals, while the other carries test signals with a 180 degree phase shift. An electronic switch (29,30) with an attenuator (22,34) on its output is arranged in each signal line.