I believe there are significant misconceptions here that should be addressed by someone closer to the Flex Radio product than myself. As I understand it, there is no need for a "roofing filter" in the SDR-5000 because of its direct conversion architecture - the same thing that makes my K2 so good without a roofing filter. Yet I have now seen shots taken at the SDR-5000 in several places for its lack of a roofing filter. Am I ignorant of the facts, or are they? Also, making the decision to purchase one radio over another based on a perceived shortfall in the 20 kHz dynamic range when the close in 2 kHz dynamic range of the SDR-5000 is superb, and possibly the best in the industry, seems wrong.
Am I missing something? Rich W1EZ ----- Original Message ----- From: "John A. McCabe" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, October 06, 2007 2:24 PM Subject: Re: [Elecraft] Comparison: K3 and SDR 5000A > Hi John, > > Although I do not have a 5000, I do have a SDR-1000. Elecraft and Flex are > both Good companies that produce great radios. However, I believe one > major difference between the K3 and the Flex 5000 will be in wider space > dynamic range. The close-in 2Khz dynamic range for the 5000 I believe was > measured by Rob Sherwood at 96db which is a good number. But the 5000 > does not have roofing filters, so if I am not mistaken, the 96db IMD > dynamic range will the same at 2Khz, 5Khz, 10Khz, 20Khz, and beyond, as > it is with most sound card based SDR's. To me a 96db Dynamic range beyond > 20Khz is not good. I believe that a 96DB dynamic range is around 40-45db > over S9, so if my calculations are correct, IMD could be a problem from a > 45db over S9 signal 20Khz or more away. That is one of the reason's why I > chose the K3 over the 5000. The K3's close in numbers will be around the > same is the 5000, but the wider spaced measurements I expect to be much > better then the Flex-5000. > > > John, KD8K > _______________________________________________ > 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 _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
