Topband: Rig Comparisons

[Bill Cromwell]

Hi Bill,

Well your choice of SDR is a later iteration. I am playing with the 
older iteration that functions similar to a direct conversion receiver 
with the 4X local oscillator and a quadrature detector ahead of the SDR 
software on the computer. If we are not to call that SDR as it has been 
then please supply a new label.

The new version doesn't even 'down convert anything to an IF but 
digitize everything on the antenna terminal. I suppose that is the only 
*real* SDR. I'm playing with little toy SDR rigs <evil grin>. Maybe that 
is a suitable new label.

73,

Bill  KU8H


On 08/03/2014 09:18 PM, Bill Wichers wrote:
> I think it depends on how much of the "r" in "sdr" is "sd".  The k3 does all the baseband modulation/demodulation in DSP, but has a pretty conventional IF path. Some people consider the K3 an SDR because it doesn't have a conventional analog modulation/demodulation stage and uses the DSP for more than just simple filtering functions in the audio stages.
>
> Personally, for me, it's not an SDR unless it just digitizes everything that it down converts and has final selectivity in the IF implemented entirely in DSP (ie no crystal filters and the like) Basically, there needs to be an ADC running in the mega sample per second range digitizing a wide swath of spectrum for me to consider something an SDR, but others seem to be more lenient with their definitions ;-)
>
> -Bill
>
> Sent from my iPad
>
>