.TH DCF77GEN 1 "DCF77 utilities" "HB9JNX" \" -*- nroff -*-

.SH NAME
dcf77gen \- soundcard DCF77 (and HBG) transmitter

.SH SYNOPSIS
.B dcf77gen
[\-a audio device] [\-s] [\-n] [\-v verboselevel] [\-g] [\-l] [\-u]

.SH DESCRIPTION
.B dcf77gen
is a soundcard modulator for time reference signals. Its format can be set
to either
.BR DCF77
or
.BR HBG
. Its main purpose was to facilitate debugging and testing of
.B dcf77rx
.

.SS OPTIONS
.TP
.I \-a
specify the path to the sound driver (default: /dev/dsp on Linux,
/dev/audio on Solaris).

.TP
.I \-s
use standard output instead of audio output. Format is 8kHz 16bit words
1 channel in the endianness of the CPU.

.TP
.I \-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! 

.TP
.I \-v
Set the verbosity level (1-2, default 0). The higher the number, the
more debugging information is written to standard error.

.TP
.I \-g
HBG mode.

.TP
.I \-l
Transmitter uses LSB (lower sideband) mode.

.TP
.I \-u
Transmitter uses USB (upper sideband) mode.

.TP
.I \-z
Transmit the time in MESZ timezone; if not specified,
it transmits MEZ.

.SH 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.
.PP
In order to build a \"real\" time signal transmitter,
it would require a very accurate reference clock.

.SH CREDITS
Hans-Guenter DF4OX/DL0PTB sent me printed documentation about the DCF77 
transmission format which helped me a lot.

.SH AUTHOR
Thomas Sailer, HB9JNX/AE4WA, sailer@ife.ee.ethz.ch