OnAirDecode EDACS trunking (WIP) with an SDR
EDACS trunking: control channel frames, calls and analog voice following of a trunked system (work in progress; message layout assumed).
- Group
- Two-way radio
- In the mode list
- 9600 bit/s control channel
What EDACS trunking (WIP) is
EDACS control channel, 9600 bit/s GFSK: the outbound frames framed by the dotting, three copies voted, with calls, talkgroups and site read under an ASSUMED message layout (not established from public sources; the raw words stay shown), a power scan of the voice channels of a frequency table you enter, and following of an analog voice channel in a wide capture. No ProVoice (digital voice)….
Frequencies and settings
OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is 9600 bit/s control channel.
What OnAir shows
EDACS control channel, 9600 bit/s GFSK: the outbound frames framed by the dotting, three copies voted, with calls, talkgroups and site read under an ASSUMED message layout (not established from public sources; the raw words stay shown), a power scan of the voice channels of a frequency table you enter, and following of an analog voice channel in a wide capture. No ProVoice (digital voice) decoding, nothing encrypted (receive only).
Limits and what it was checked with
Checked with generated signals and impairments; recordings of real signals welcome.
Which radio you need
Any radio that tunes this range works. An RTL-SDR covers roughly 24 MHz to 1.7 GHz, and every other radio in the radio guide reaches it too. Antenna height and a clear view of the transmitter matter most.
Receiving and the law
Questions about EDACS trunking (WIP)
Can I decode EDACS trunking (WIP) with an RTL-SDR?
Usually yes for narrowband signals, as an RTL-SDR tunes roughly 24 MHz to 1.7 GHz at up to about 2.4 Msps. Wide signals such as TV channels need a faster radio, and OnAir says next to the source what the selected radio can do.
Is it legal to receive EDACS trunking (WIP)?
In many countries it is illegal to intercept or disclose private radio communications. OnAir is a receiver: encrypted calls show up only as encrypted and are never decrypted, and voice needs a library you install yourself. Follow the law where you live.
Can I try EDACS trunking (WIP) in OnAir without a radio?
Yes. Most modes include a built-in synthetic test signal, so you can open the screen and try the controls before you own a radio.