.\" Text automatically generated by txt2man
.TH GRDAB 1 "02 December 2018" "" ""
.SH NAME
\fBgrdab \fP- DAB / DAB+ receiver for software defined radio
\fB
.SH SYNOPSIS
.nf
.fam C
\fBgrdab\fP [\fIglobal_options\fP] <command> [\fIoptions\fP]

.fam T
.fi
.fam T
.fi
.SH DESCRIPTION

All SDRs supported by gr-osmosdr and which can tune to the DAB frequencies can be used with \fBgrdab\fP. It has been verified to work with RTL-SDR, HackRF and USRP B200. \fBgrdab\fP can receive both DAB and DAB+ audio.
.TP
.B
Calibration:
.PP
When connecting a new radio, run:
.PP
.nf
.fam C
    grdab adjust

.fam T
.fi
This will bring up a GUI where you will see the frequency spectrum and the constellation diagram.
.RS
.IP 1. 4
Drag the channel selector to a valid DAB/DAB+ frequency in your area.
.IP 2. 4
Adjust the gain sliders such that frequency spectrum looks good. It should be an almost square looking wide signal.
.IP 3. 4
Adjust the ppm slider until the constellation diagram consists of 4 quite confined dots.
.IP 4. 4
Then click 'save configuration'
.IP 5. 4
Your SDR is now calibrated and can be used to receive DAB/DAB+ audio.
.RE
.PP
The calibration data is stored in the file ~/.grdab/adjustment.yaml. Whenever connecting a new SDR, you will have to repeat the adjustment procedure above.
.TP
.B
Check available channels:
.PP
To see what channels are available on a chosen frequency, run:
.PP
.nf
.fam C
    grdab info -f <frequency_in_mhz>

.fam T
.fi
.TP
.B
Listen to DAB/DAB+:
.PP
When you find a channel, you can start receiving audio with:
.PP
.nf
.fam C
    grdab receive -f 227.360 --bit_rate 80 --address 204 --subch_size 60 --protect_level 2 --audiorate 48000

.fam T
.fi
where you replace the different \fIoptions\fP with the output from '\fBgrdab\fP info' for the desired channel. You might have to experiment with a few different values for '\fB--audiorate\fP' (such as 44100 or 48000). Note that DAB+ is default. To receive classic DAB, add '\fB--classic\fP' an argument.
.TP
.B
Ncurses app:
.PP
If you create a file called ~/.grdab/channels.yaml, and list all the channels in your area,
you can afterward use the \fBgrdab\fP ncurses application:
.PP
.nf
.fam C
    grdab curses

.fam T
.fi
It allows you to select a channel and listen to it. See /usr/share/doc/gr-dab/examples/channels.yaml for an example of a channels.yaml file
.TP
.B
ZMQ source:
.PP
To allow starting and stopping \fBgrdab\fP without having to reinitialize the Software Defined Radio, you can start apps/sdr-zmq-daemon in the background. If you then start \fBgrdab\fP with `\fBgrdab\fP \fB-z\fP`, it will start much faster.
.SH OPTIONS

Commands:
.PP
.nf
.fam C
    grdab [global_options] adjust [options]   - Adjustment GUI for gain, timing error etc.
    grdab [global_options] info [options]     - List DAB/DAB+ channels on a specific frequency
    grdab [global_options] receive [options]  - Receive audio from a DAB/DAB+ channel
    grdab [global_options] curses [options]   - Ncurses GUI for selecting between multiple channels


.fam T
.fi
.TP
.B
Global \fIoptions\fP:
.RS
.TP
.B
\fB-z\fP
ZeroMQ mode. Expects zmq-sdr-daemon to be running
.TP
.B
\fB--server\fP <address>
Address to ZeroMQ (Default is: tcp://127.0.0.1:10444)
.TP
.B
\fB--server_control\fP <address>
Address to ZeroMQ for configuration (Default is: tcp://127.0.0.1:10445)
.RE
.TP
.B
Other \fIoptions\fP (common for all):
.RS
.TP
.B
\fB-f\fP/\fB--freq\fP <freq>
Receive frequency in MHz
.RE
.TP
.B
Other \fIoptions\fP (for '\fBgrdab\fP receive' only):
.RS
.TP
.B
\fB-a\fP/\fB--audiorate\fP <rate>
Audio rate in Hz (default: 48000)
.TP
.B
\fB--bit_rate\fP <val>
Bit rate of the DAB/DAB+ channel.
.TP
.B
\fB--address\fP <val>
Address of the DAB/DAB+ channel.
.TP
.B
\fB--subch_size\fP <val>
Subchannel size of the DAB/DAB+ channel.
.TP
.B
\fB--protect_level\fP <val>
Protection level of the DAB/DAB+ channel.
.TP
.B
\fB--classic\fP
Use DAB instead of DAB+
.SH SEE ALSO
\fBsdr-zmq-daemon\fP(1)
.RE
.PP

.SH AUTHOR
This manual page was written by Ruben Undheim <rubund@debian.org> for the Debian project (and may be used by others).
.RE
.PP