After correctly configuring and starting the QO100 transceiver, you can see the spectrum of the QO100 narrowband transponder in the spectrum/waterfall diagram above:
In the lower spectrum/waterfall you can see an enlarged section around the RX frequency:
the receiver is tuned to the center beacon, which can be seen here in the center at offset-0 Hz.
this is done with the mouse or a touch screen according to these two buttons:
So you select RX-QRG and/or TX-QRG and then click (tap) in the waterfall.
Mouse wheel: changes the frequency for fine tuning. Pressing the ALT or SHIFT (shift) key at the same time will change the mouse wheel increment.
first one selects the frequency in the upper spectrum/waterfall. If one wants to listen to a running QSO, one clicks on the left edge of the signal, because it is USB (Upper Sideband).
Now you go to the lower waterfall and do the fine tuning. Either with the mouse wheel or touch screen you click in the area around the 0 Hz line to shift the frequency.
PTT … Click to send (will turn red). Alternatively you can use the shift keys as PTT.
in many cases the default setting is ok. If you want to correct the volume settings, this is done with the volume mixer “pavucontrol”. This is installed and can be called by clicking the “MIXER” button.
In addition to the volume setting, you have comfortable options for assigning audio devices. For example, you can switch the receive signal between the headphones or the speakers in the HDMI monitor without having to change the SETUP of the QO100 transceiver.
If the audio source is too quiet, you still have the option of switching on a pre-amplification with the “AUDIO” button. An always active AGC prevents overdriving the Pluto. Nevertheless, spurious emissions can occur if the microphone level is extremely high.
Screen icon …setting of different screen resolutions to adapt the window to the monitor used.
CAL … Menu for convenient setting of the correction values for the pluto and LNB reference frequency
LOCK/FREE … Switching on and off the automatic beacon synchronization. When using a slow computer like Raspberry 3B+ the beacon synchronization must be switched off (FREE).
SAVE/LOAD … Memory for the RX and TX frequency