[Ham-Linux] Any good DSP filter software?

[Leif Asbrink]

Hi Jim and all,

> I'm looking for good noise filtering software for common computer
> soundcards.  Essentially, does anyone know of software-based DSP
> programs that turn the soundcard into an effective noise filter.  =
Summer
> will be here before we know it, and an effective way to remove static
> noise in Linux/BSD would be a beautiful thing.

Have a look at Linrad:
http://ham.te.hik.se/~sm5bsz/linuxdsp/linrad.htm
There is an Eu mirror at:
http://www.g7rau.co.uk/sm5bsz/linuxdsp/linrad.htm
and a US mirror at:
http://nitehawk.com/sm5bsz/linuxdsp/linrad.htm

Linrad has a clever blanker that subtracts the waveform
of interference pulses. To do this Linrad has to be calibrated
by use of a pulse generator. The amount of pulses that 
can be removed depends on the analog bandwidth.
With direct conversion and a 96kHz soundcard the
useful bandwidth is above 90kHz and pretty high
pulse rates can be treated. Strong signals are 
prevented from reaching the blanker by automatic
notch filters.

73

Leif  /  SM5BSZ