[Elecraft] Just thinking

[Ron D'Eau Claire]

I agree, Joe. The direct conversion (RF to baseband) architecture has been
around since the earliest days of radio for a reason. The superheterodyne
format using "intermediate" frequencies offered selectivity that wasn't
available in the past but at a cost: spurious responses and very sensitive
gain distribution are just two of the most severe. But 'superhets' were
better and so became the format of choice. 

But modern techniques now provide the selectivity needed without the
superheterodyne format with all of its issues. The quadrature sampling
detector is one of those. 

We've seen a lot of work in the direct conversion format since the 1950's,
but development has accelerated rapidly in recent years as any casual review
of the literature will show. It's exciting that Wayne chose this approach
for the KX3, given the high-performance engineering skills he has
demonstrated with the other Elecraft rigs. 

73, Ron AC7AC 

-----Original Message-----
Howdy Gang:

Perhaps I should have made my previous comment regarding the KX3 and my
"daydream" K4 a bit clearer.

I should have been more specific in terms of the QSD (quadrature sampling
detector) architecture of the KX3 as related to my "day dream" K4.

While the K3 is controlled via firmware (SDR) it has a conventional superhet
architecture as opposed to a QSD scheme.

					73, Joe W2KJ
7