About:

timestampSDR is designed to take the UDP stream output from certain SDR receiver software (currently GQRX and rtl_fm) and record transmissions to time-stamped .wav files, discarding silence. This can allow you to quickly review transmissions that occurred over a long period of time.

• ✔️ Works on Linux running GQRX or rtl_fm
• ✔️ Works on Windows 10 running GQRX via pothosSDR
• ❔ Should work on MacOS, but not tested (seeking feedback!)

Getting started:

• Must have node.js installed.
• Clone this repo, or download it and extract the zip file.
• Navigate to the program directory and run npm install to install the program dependencies.
• Refer to the wiki for instructions on setting up your SDR receiver software. Currently this includes GQRX and rtl_fm. GQRX is more user-friendly and seems to provide better audio, rtl_fm runs efficiently on low-spec devices.
• Regardless of your receiver software, make sure your squelch is adjusted well. timestampSDR cannot differentiate static from meaningful transmissions.

Usage:

node main.js [options]

Option	Description	Default
--timeout	After transmission, wait seconds before saving/deleting file and moving on	5
--minDuration	After timeout, if recording was less than seconds, file is deleted	5
--maxFiles	Number of files to save before exiting program	5
--dateFmt	Date formatting: "datetime", "unix", or custom moment.js format	"datetime"
--sampleRate	Sample rate in Hz	48000
--channels	1 for mono, 2 for stereo, etc	1
--bitDepth	Bits per sample	16
--host	Local IP address serving data	"127.0.0.1"
--port	Local UDP port serving data	7355
-p	Print options used and source they were chosen from (CLI, config file, default)

Note:

• Recordings are saved in the recordings subdirectory in the main program directory.
• Timeout resets if a new transmission comes in before timeout finishes.
• Silence is not recorded, and doesn't count towards minDuration.
• To set your own default options (which can be overridden by passing in arguments), you can modify config.js.