man dcf77gen (Commandes) - soundcard DCF77 (and HBG) transmitter
NAME
dcf77gen - soundcard DCF77 (and HBG) transmitter
SYNOPSIS
dcf77gen [-a audio device] [-s] [-n] [-v verboselevel] [-g] [-l] [-u]
DESCRIPTION
dcf77gen is a soundcard modulator for time reference signals. Its format can be set to either DCF77 or HBG dcf77rx
OPTIONS
- -a
- specify the path to the sound driver (default: /dev/dsp on Linux, /dev/audio on Solaris).
- -s
- use standard output instead of audio output. Format is 8kHz 16bit words 1 channel in the endianness of the CPU.
- -n
- do not use the `mmap()` way of approaching the soundcard, which means, do not read directly from the soundcard dma buffer. Some soundcards do not support mmap mode. This option is experimental, it is not yet tested how good the results will be!
- -v
- Set the verbosity level (1-2, default 0). The higher the number, the more debugging information is written to standard error.
- -g
- HBG mode.
- -l
- Transmitter uses LSB (lower sideband) mode.
- -u
- Transmitter uses USB (upper sideband) mode.
- -z
- Transmit the time in MESZ timezone; if not specified, it transmits MEZ.
BUGS
The program uses the system time at startup and then derives the clock from the soundcard. It could be made a command line parameter to specify transmit time.
In order to build a it would require a very accurate reference clock.
CREDITS
Hans-Guenter DF4OX/DL0PTB sent me printed documentation about the DCF77 transmission format which helped me a lot.
AUTHOR
Thomas Sailer, HB9JNX/AE4WA, sailer@ife.ee.ethz.ch