This section applies mostly for 50 MHz and higher operation.
MSK144 and the Fast JT9 modes are both capable of split frequency operation. This is recommended for busy frequencies or when calling CQ on a calling frequency. Your rig must be controlled via CAT, and must have more than one VFO.
First, you will need to check "Enable VHF/UHF/Microwave features" in the General panel of the Settings menu;
Next, select either MSK144 or one of the Fast JT9 modes (E through H) from the Mode menu;
In the Radio panel check "Rig" under "Split Operation";
Place your rig's main VFO on the frequency you wish to receive on. On the main program screen, check the box labeled "Tx CQ nnn" where nnn is the frequency where you wish to call CQ. On the example below, you will be transmitting on 50.280.
This will place your rig in split mode. Using the above example, your transmit VFO will then be set to 50.280, and your receive VFO will stay on the frequency you want to be called on (where you had initially placed your rig on prior to selecting the "Tx nnn" button). On the example below, the rig is transmitting CQ on 50.280 and the second VFO is listening on 50.286. WSJT-X will automatically insert "CQ nnn..." on the Tx6 box. Once someone answers your CQ and you double-click on that decode on the main screen, then your transmit VFO will automatically QSY to the frequency you were listening on, and will then continue with the QSO if you have also checked "Auto Seq". Your receive VFO will stay on the frequency where you initially started on.
Don't forget to deslect the "Tx CQ nnn" box to go back to regular non-split mode!