[hpsdr] [qs1r] SDR-IQ, Perseus, QS1R bench measurements (corr.)

[Philip Covington]

On Tue, Apr 22, 2008 at 11:25 AM, Marco IK1ODO -2 <ik1odo at spin-it.com> wrote:
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>  I mistyped the address:
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>  http://www.spin-it.com/download/SDR_RX_measurements.pdf
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>  73 - Marco IK1ODO / AI4YF
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Update:

I found the problem in the dc offset correction that was causing the
spur at zero when a large signal is within the passband.  I also found
the software error that causes the noise floor to jump when dither is
enabled.  Fortunately they were both easily corrected in the DSP chain
in the QS1RServer software.   I will be posting updated files with
these corrections.

In a quick test, enabling dither now only raises the noise floor by
~0.5 dB within the claims for the LTC2208 datasheet.

The Preselector/Amp/Attenuator board will be available in 6-8 weeks.

Phil N8VB

 1208904245.0