In a message dated 1/17/07 6:37:02 AM Eastern Standard Time, [EMAIL PROTECTED] writes:
> The G2DAF receiver did it for me when he demonstrated gain and s/noise > ratios. If I remember rightly he had no gain in the front end, only > matching > to the antenna and input filters; all the gain was in the IF. Depends on what version he built. The last version used a push-pull RF amplifier and mixers, all low-noise triodes. There *was* some gain in that front end. The RF amplifier had just enough to make up for the losses in the tuned circuits, and the two mixers had some gain, but not a lot. They were primarily designed for dynamic range and low noise, not gain. The result was that there wasn't much gain ahead of the selectivity. Another example is the fabled Squires Sanders SS-1R receiver, which used balanced 7360 mixers and no RF stage. But it cost $700 back in the early 1960s! IMHO, the trend started with a 1957 QST article by W1DX called "What's Wrong With Our Present Receivers?". There was also QST articles called "The Miser's Dream" in 1965, and "An Experimental Receiver of 75 Meter DX Work", in 1971, which showed receivers using those basic principles. 73 de Jim, N2EY _______________________________________________ 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
