Brian, Yes I agree about your assessment on the preselector, but who is going to take the time to design, test and market the preselector. We could talk all day what it should be in theory, but until someone takes the time to take their theory and make it a viable product all we have is " what if"
73, Robert KB6QXM "Ham Radio Open Conversation" Yahoo group owner/moderator ----- Reply message ----- From: "Brian Lloyd" <brian-wb6...@lloyd.com> To: "Robert Costa, KB6QXM" <kb6...@yahoo.com> Cc: "Carol F. Milazzo, KP4MD/W6" <kp...@cfmilazzo.com>, <flexradio@flex-radio.biz> Subject: [Flexradio] The new 472-479 kHz band - REAL DX Date: Tue, Feb 21, 2012 9:35 am On Tue, Feb 21, 2012 at 8:47 AM, Robert Costa, KB6QXM <kb6...@yahoo.com> wrote: What I want to see is someone design a tuneable preselector with many adjustable parameters. Anyone up to the task. I will even build your website to market it. Signal levels tend to be pretty strong unless using a small loop antenna, and then you need a preamp. No reason that the small, multi-turn, receiving loop antenna cannot itself be made tunable, followed by a preamp and a second tuned stage that is gang-tuned with the loop. (If Q is low enough the loop can be tuned with lumped constants.) But if one wants the preselector to be independent of the loop, I would use a link or tapped input to the first LC network, loosely-coupled to a FET gain stage, followed by a second, identical LC network, followed by a FET buffer to match a 50-ohm feedline to the RX. Just thinking aloud here. -- Brian Lloyd, WB6RQN/J79BPL 3191 Western Dr. Cameron Park, CA 95682 br...@lloyd.com +1.767.617.1365 (Dominica) +1.916.877.5067 (USA) _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
