User Manual

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The next parameter to select is the mixer device associated with the already
selected sound card, using the Mixer device drop-down list, and the Mixer
line (the sound card input line). If the signal is arriving at the sound card via
an external cable, the cable should be physically connected to the Line
input of the sound card. If the receiver is connected internally, most probably
the input would be called Aux or CD Line.
In the drop-down list of sound card inputs, each line is available either as
normal, or Reversed. If the reversed line is selected, this means that the left
and right channels (of the sound card stereo input) are to be reversed.
Normally, you should not need to select any of these reverse inputs.
However, there is a very small number of sound cards where the left and
right inputs are swapped. Normally, the G303 Demodulator expects the
receiver output to be connected to the right sound card input. If it is to be
connected to the left input instead, the reverse input line needs to be
selected from the drop-down list.
With some laptops, only the Microphone input may be available and in such
case you will need to connect the receiver to the Microphone input instead,
and also select this input in the demodulator Setup panel. Certain sound
cards, in particular Creative Audigy 2, have a design problem which
prevents them from using the Line input in a full duplex mode. In such case,
you will also need to use the Microphone input.
If you are using the Microphone input instead of Line input, please check if
there is an Advanced button under the Microphone volume control in the
sound card control panel. If so, then click on it and uncheck the +20dB gain
check box if it exists. The extra large gain would result in overloading the
sound card, and cause distortion.
The last parameter to set is the Input level. Set it to half the maximum level
initially. When you then tune the receiver to your first station, you should
return to this, and adjust the Input level below the point when the Clipping
indicator turns red. If the signal still sounds distorted, reduce the level
further down until the distortion disappears.
While adjusting the Input level, you will also see the noise floor of the signal
spectrum shown in the main demodulator window rising proportionally.
This completes the software installation process. The G303 software then
automatically configures the sound card control panel. It may be interesting
to describe what it actually does and why: