I don’t understand why this is failing:
Traceback (most recent call last):
File “./top_block.py”, line 184, in
tb = top_block(options)
File “./top_block.py”, line 97, in init
1, bw, -7.0, 7.0, 150, firdes.WIN_HAMMING, 6.76))
File
“/usr/local/lib/python2.5/site-packages/gnuradio/gr/gnuradio_swig_py_general.py”,
line 2729, in band_pass
return _gnuradio_swig_py_general.firdes_band_pass(*args, **kwargs)
IndexError: gr_firdes check failed: 0 < fa <= sampling_freq / 2
When I specify negative frequencies, it does this.
I thought that with a complex filter, I could specify negative
frequency?
This particular filter is a decimating filter that is decminating from
500KHz sample rate down to 32KHz sample rate,
with cutoff between -7KHz and +7KHz. But I’m triggering this error,
and I don’t understand why. This is from
a GRC flow-graph.
–
Marcus L.
Principal Investigator, Shirleys Bay Radio Astronomy Consortium