That information is based on input from K7AY (cocoaModem) and G3YYD (2-Tone). The software decoders do a better job when supplied with audio at least 400 Hz wide without frequency shaping from the IF (DSP) filter. The Dual Band Pass filters in general introduce significant phase delays and amplitude inequality which results in poorer decoding accuracy in modern FFT based demodulators - although the frequency shaping may be of value in older amplitude (filter/detector) style demodulators.
73, ... Joe, W4TV On 1/6/2014 1:26 PM, Mike K8CN wrote:
Lee, Ed, W0YK, has a commentary on this very subject in the current issue of NCJ (subscription required). Perhaps he will weigh in directly here, but his recommendation was to use the normal filter rather than dual passband. This is not an issue unique to the K3. 73, Mike, K8CN -- View this message in context: http://elecraft.365791.n2.nabble.com/Dual-Pass-Band-tp7582564p7582570.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ 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
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