WiNRADiO G65DDC User’s Guide
60
Useful notes about AGC to remember:
1. In AM, AMS, LSB, USB, ISB, DSB and CW modes, the gain setting affects
loudness. If the receiver volume appears too low (and yet the volume control is
all the way up), make sure that AGC is enabled
2. If the AGC is enabled and the sound is distorted despite the volume being
turned down, make sure that the AGC reference level is not set too high. If the
volume is too low, try to increase the AGC reference level.
3. If the AGC is disabled and the sound is too weak despite the volume control
being all the way up, try to increase the manual gain.
4. In LSB, USB, ISB, DSB and CW modes, manual gain is often preferable to
automatic gain. This is because there is no constant “carrier” for the AGC to
act upon and maintain at a constant level. If AGC is used, then the slow
setting is preferable.
Noise Blanker
The
Noise Blanker
can be used for removal of random high-level noise-spikes
resulting from atmospheric effects and man-made interference.
There are two types of noise blankers available, one using the
Short Time
DDC Averaging
method and another using the
ADC Input Threshold
method.
The
Short Time DDC averaging
method is based upon comparing the
instantaneous signal level at the DDC output (demodulator input) to a short-
time exponential average. If the instantaneous level exceeds the short-time
average, these samples will be replaced with zeros.
With the
ADC Input threshold
method, the blanking effect occurs much
earlier in the signal processing chain: The signal samples arriving from the