tune: a plain carrier

Puts an unmodulated carrier on one frequency. Useful for finding your signal on a receiver, checking a filter, or measuring the Pi’s frequency error. Code: tune.go.

Fields

JSON	Go field	Type	Required	Rules
frequency	Frequency	float64	yes	Hz, 5000 to 1500000000
exitImmediate	ExitImmediate	*bool	no	true adds -e: the program exits at once and leaves the carrier running
ppm	PPM	*float64	no	Clock correction in parts per million, must be greater than 0

tune keeps transmitting until it is stopped, so give Exec a timeout or call Stop. With exitImmediate, the process exits right away and the carrier stays on after Exec returns. Stopping that carrier is up to you.

ppm must be positive here, while pifmrds and pift8 accept any value. A negative correction is refused.

Example

{
  "frequency": 434000000,
  "ppm": 2.5
}

Runs:

stdbuf -oL "$GORPITX_PATH/tune" -f 434000000 -p 2.5