[CQ-Contest] Kenwood TS-850 vs TS-870

[Scott Ellington]

The TS-870 lacks a cw filter ahead of the DSP.  Kenwood attempts to
compensate by passband shifting of the two SSB filters to narrow the
bandwidth, but that doesn't result in a great CW filter.  As a result,
dynamic range for nearby signals is limited to by the A/D converter to
around 60 dB.  No amount of fancy DSP after the A/D converter can
improve this.  By comparison, a pair of cascaded 500 Hz crystal
filters should provide over 100 dB of dynamic range at 1 kHz
separation.  Until someone figures out how to build a fast 24 bit A/D
converter, all DSP receivers without narrow crystal filters will have
this limitation.


--
73,

Scott  K9MA
sdelling at facstaff.wisc.edu

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