Yep. There's many real advantages in the direct conversion (d.c.) architecture. Note that the popular regenerative receivers of the 1920's were "direct conversion". Like modern receivers they heterodyned the signal frequency directly to audio. When they were "rediscovered" in the 1970's using solid state detectors, people were very enthusiastic about how quiet they were.
What Elecraft has done is to remove the limitations inherent in the direct conversion design: limited dynamic range (especially when using a regenerative detector) and limited selectivity, both in separating signals and in the fact the early designs could not suppress the unwanted sideband. All of that is accomplished while keeping the simplicity and low noise characteristics of the first direct conversion receivers. D.C. receivers have a special place in my heart because, in High School, I got to wondering about what would happen if the I.F. of a superhet was reduced to zero Hz. I took the idea to my Radio Shop instructor who said, simply, "try it". So I did and I was amazed, even though I was using vacuum tubes (1950's) which tended to be very microphonic. Now convinced I had a new receiver design that would make a big splash (and perhaps some serious cash for me) my instructor smiled and said, "Did you check the literature?" And so, I found that I was not the first -- not even remotely the first, to make a direct conversion receiver. But even though my mistress had known earlier lovers, my admiration for her has never faded. 73 Ron AC7AC -----Original Message----- From: Fred Smith [mailto:m...@mo-net.com] Sent: Saturday, April 13, 2013 7:46 PM To: 'Ron D'Eau Claire'; elecraft@mailman.qth.net Subject: RE: [Elecraft] Benefits of Buying a Factory Assembled KX3 All I can say about the filters in my KX3 is that they work and very well I might add. This little radio never ceases to amaze me every day that I own it. 73, Fred/N0AZZ K3 Ser #'s 6730/5299--KX3 # 2573--K2/100--KAT100 P3/SVGA--KPA500--KAT500--W2 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
