I can confirm the USB interface of the DR-891 and Yaesu DIN5 cable Yaesu DIN5 Digirig Cable Set – digirig works with the Ten Tec Eagle 599. This should also work with the Argonaut VI Model 539. I can also confirm GPIO PTT works with WSJT-X by creating hamlib_settings.json with the following lines of code and saving it to C:\Users{username}\Appdata\Local\WSJT-X
{
“config”: {
“ptt_type”: “CM108”,
“ptt_bitnum” : “3”
}
}