pift8: FT8

Sends an FT8 message, the weak-signal digital mode with 15-second transmit slots. The module name is pift8, the binary name, while the Go names are FT8 and ModuleNameFT8. Code: ft8.go.

Fields

JSON	Go field	Type	Required	Rules
frequency	Frequency	float64	yes	Dial frequency in Hz, 5000 to 1500000000
message	Message	string	yes	The FT8 message, not empty or only spaces
ppm	PPM	*float64	no	Clock correction in parts per million, any value; without it the program uses NTP
offset	Offset	*float64	no	Audio offset in Hz, 0 to 2500; the program defaults to 1240
slot	Slot	*int	no	0 first 15 s slot, 1 second slot, 2 every slot
repeat	Repeat	*bool	no	true adds -r and keeps sending every 15 s

The tone goes out at frequency + offset. gorpitx does not check the message format; pift8 encodes it, so a message FT8 cannot encode fails in the program, not in validation.

FT8 slots are tied to the clock, so the Pi’s time has to be right. Keep NTP running.

Example

{
  "frequency": 14074000,
  "message": "CQ N0CALL FN31",
  "offset": 1500,
  "slot": 1,
  "repeat": true
}

Runs:

stdbuf -oL "$GORPITX_PATH/pift8" -f 14074000 -m "CQ N0CALL FN31" -o 1500 -s 1 -r

With repeat, the program never exits by itself. Give Exec a timeout or call Stop.

Message shapes

A standard exchange goes like this, one message per slot:

Step	Message
Call CQ	CQ N0CALL FN31
Answer with your grid	N0CALL N1CALL EM69
Signal report	N1CALL N0CALL -15
Report back, with R	N0CALL N1CALL R-08
Confirm	N1CALL N0CALL RR73
Sign off	N0CALL N1CALL 73