Step 2; Figure 50 Fldigi Tune Button - Kenwood TS-990S Configuring Manual

I chose this frequency as it is middle of the 'normal' TX audio passband of the SSB filters. Depending on
your exact transceiver this may be between 900 Hz and 1800 Hz. Fldigi has a setting for this and it is
called 'Sweet Spot', a topic for further discussion.
We will cause the software to transmit the PSK31 'idle' signal by using the 'TUNE' button in Fldigi. This
control button will put Fldigi into TX and supply the correct audio signal to the TS-990S. See the figure
below for the location of this button (top left).

Figure 50 Fldigi Tune Button

Step 2

Open the Control Panel > Sound > Playback device selection, and double click on the TS 990 TX audio
device. Select the Levels Tab.
Configuring the TS990S for Fldigi
Tutorial by Mitch Baum – AE2A
Page 47