There is a new mode from K1JT and K9AN called FT-8. The TX/RX windows are 15 seconds instead of the 1 minute toggle in JF-65 and JT-9 modes. The downside FT-8 presently has a slightly worse S/N compared to JT-65. Download v 1.8 rc1 from the K1JT site
Setup with any 6xxx series Flex is simple.
Under General fill in the your particulars and make your choices
For radio I use TS-2000 protocol and SmartCat port 4 to get band data, freq and PTT control
Audio is on DAX 1 and DAX TX. Make sure DAX 1 is turned on on the freq flag of the panadapter, and turn on RX1 and TX in DAX. Set mic input to PC. Set DAX RX1 level to give 50% on the FT-8 client and DAX TX gain to keep you just out of ALC, and use the power control on the radio to set the power level
Go make a contact
These modes require a pretty precise timing so I keep my computer clock trained to the correct time using this program