When considering the differences between the K3 and IC-7800/7700/756PRO3 or FTDX-9000/2000, apart from the K3's lack of band-scope, numerous large knobs and colour screens, the other thing that stands out is the selection of the 1st IF frequency.
Most other radios use a VHF 1st IF (typically about 70MHz) whereas the K3 has been designed to use 8MHz. Icom and others point out that a VHF IF allows their radios to obtain superior image rejection. This is done at the expense of non-ideal filter bandwidths though, as it's difficult to design narrow filters at around 70MHz. I think the K3 manages to provide 1st IF filter bandwidths of just 400Hz doesn't it? Does anyone have a useful link to the definition of image rejection? Does the K3 manage to obtain image rejection comparable to Icom's and Yaesu's flagships? If so then it seems to me that Icom and Yaesu seem to be relying on a proven RF design and instead are concentrating their current efforts on ergonomics and presentation. There's nothing wrong with that though. Thanks, Shane VK5ABQ South Australia. -- View this message in context: http://www.nabble.com/K3-IF-Design-tp17418075p17418075.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ 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
