> what do you think other than the obvious differences (knobs, > bandscope, computer, $$, etc.) K3 or SDR-5000?
The design philosophy of the two radios is completely different. The Flex-5000 front end is "broad as a barn door" - it applies all the energy in an entire amateur band and adjacent frequencies directly to the DSP analog to digital converter. This does two things. First the ADC is required to have a much greater dynamic range in order to deal with a 10 to 20 dB larger but very low probability instantaneous peak voltage (very high peak to average ratio). Second it requires the DSP software to sort out all the signals in roughly a 200 kHz "window." This results in increased processing time and more delay. The front end of the K3 has a narrow "roofing" filter very close to the first mixer which limits the bandwidth applied to the DSP ADC. This provides two advantages. The peak to average ratio of the signal applied to the ADC is not a high so the dynamic range of the ADC can be better used (better optimized to conditions) which theoretically provides better dynamic range (either better sensitivity or more resistance to IMD). Secondly, by dealing with a more narrow spectrum, the DSP can be made faster for equivalent resolution (selectivity) or the available processing power/time can be used for improved performance like, noise reduction/signal correlation, context and focus filtering, spatial processing, etc. The Flex philosophy has an advantage in that it can implement in-band dual receive with a single set of receiver hardware. Its DSP can demodulate any signal within the 196 KHz "window" and provide one signal on each audio channel. With a multi-channel audio card or multiple audio cads and enough computing power, the Flex can be extended to "n-channel receive" without additional hardware. The K3 design is limited to a single signal per DSP channel. Both design philosophies have their place. The K3 is like a high performance sports car - it does one thing and does it better than any other product. The Flex-5000 is like a fully loaded luxury SUV - it has every option imaginable but it lacks precision, handling and speed. Your choice depends on whether you want frills or performance. 73, ... Joe, W4TV > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Ross Stenberg > Sent: Saturday, December 22, 2007 1:12 PM > To: [email protected] > Subject: [Elecraft] K3 or SDR-5000? > > > I realize that this is like asking a pack of dogs if they > like bacon, but > what do you think other than the obvious differences (knobs, > bandscope, > computer, $$, etc.) K3 or SDR-5000? > > 73 and Merry Christmas > > Ross Stenberg > K9COX > > _______________________________________________ > Elecraft mailing list > Post to: [email protected] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
