Tom Rauch wrote:
>Hi ian,
>
>> When doing a comparative review of several DSP audio filters, I found that
>> most - but significantly not all - units gave good CW filtering
>> performance right down to the lowest signal/noise ratios. I had been
>> expecting to hear "on or off" quantization effects at low levels, but
>> there was no sign of that because the noise added random dither to the
>> incoming signal and avoided the threshold effects. The "noise reduction"
>> feature was universally useless at low signal levels, as you might expect.
>
>That's because the filters you tested are after the receivers analog
>selectivity. Look at the 756PRO reviews coming out, where it is
>compared to things like the 1000MP.
>
Which "that" are you referring to, Tom - the good low-noise performance
of the selective DSP filters, or the ineffectiveness of the DSP noise
reduction?
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.demon.co.uk/g3sek
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