The filters in SDRMAXIV vers
(Jan 4 2011)
Test method.

SDRMAX vers beta

When the test file is played with SDRMAXIV-, the screen may look like figure 1. It depends of course how the parameters in SDRMAXIV are set.

Fig 1. SDRMAXIV- running sim1.wav. (qs1r-sim.wav)

The loudspeaker output from SDRMAXIV sounds like this: sim1-qs1r.mp3 (495600 bytes.) The on-off keyed signal is at a level that is similar to the noise floor level in the beginning and end of the file where the data comes from an old Perseus recording.

The tested SDRMAXIV version was Beta 1 downloaded December 2010.

The details of the loudspeaker output are shown in figures 2 and 3 which are waterfall graphs produced by Linrad with sim1-qs1r.mp3 as the input (before conversion to mp3).

Fig 2.The loudspeaker output from SDRMAXIV when running the test recording sim1.wav. This waterfall graph is produced by Linrad with the loudspeaker output from SDRMAXIV as input.

Fig 3.The loudspeaker output from SDRMAXIV This the same as figure 2 at a 10 times higher waterfall speed.

The loudspeaker output of SDRMAXIV on an oscilloscope looks like figures 4 and 5 at different X-axis magnification.

Figs 4 and 5The loudspeaker output from SDRMAXIV in the time domain when the signal sweeps across the filter.

The SDRMAXIV software does not meet the performance of the QS1R hardware. Some of the spurs are well above the hardware noise floor.

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