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possible to happen. If the total electric power level ADC receives is too high,
KC908 would decrease the gain tentatively until the overload is gone. On the
other hand, the gain would increase when the level drops to maintain a
relatively high sensitivity. In addition, to prevent the possible gain oscillation
caused by the rapid change od the signal, the stagnate interval is set to 20dB
by default, and user can specify this setting in LEV-gain-follow signal-stagnate
interval.
RF gain affects the anti-interference ability greatly. Since it's hard to assess
the electromagnetic environment comprehensively in real-time bandwidth,
adding RF gain into auto adjustment would probably get the wrong result. So
the RF gain needs to be set manually, and the recommended value is 20dB. In
places where the electromagnetic environment is ideal and the signal is weak,
it can be set to 40dB to improve the sensitivity. Yet, a 40dB gain would
drastically compromises the anti-interference ability. Use PRE-AMP button as
the shortcut to set the RF gain.
Due to the fact that the criterion of ALC control is the total level within the
whole sampling bandwidth, signal changes outside the displayed part also
account for ALC action, which can appear as rapid changing ground noise.
Since it's possible the overload happens before ADC, simply adjusting
according to the sampling level might not be enough to be a prevention.
Moreover, ALC is not capable of eliminating this kind of overload unless a
NOTE
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