About the receiver filter sequence in the SN90 system
The filters in the SN90 system are implemented in “series”. Any changes to a filter setting may therefore have an effect on subsequent filters.
Image
A Bottom Filter
B Noise Filter (1)
C Gain & TVG (Time Variable Gain)
D Noise Filter (2)
E AGC (Automatic Gain Control)
F RCG (Reverberation Controlled Gain)
G Display Gain
H Ping-Ping Filter
Note that Gain, TVG (Time Varied Gain) and Display Gain are not filters, but included only to illustrate the complete "signal path".