>From the RTTY reflector, the short article by K0SM in the link below may be of interest to K3 users. With this enhanced FSK filtering, the K3 has a significantly narrower FSK bandwidth than any other FSK radio that I'm aware of. Hopefully, other manufacturers will follow suit.
The Beta DSP 281 firmware will be released to production soon. Meanwhile, if anyone is interested in trying it, let me know and I'll email it to you. Ed W0YK > -----Original Message----- > From: RTTY [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Thursday, March 21, 2013 6:16 PM > To: RTTY Mailing List > Subject: [RTTY] K3 reduced-bandwidth RTTY analysis > > Hello again, > > I have finally gotten around to finishing up a short analysis of the > reduced-bandwidth FSK keying in the K3. As many of you are aware, > Elecraft made some beta firmware available several weeks ago that > attempts to reduce the clicks that result for unshaped keying. They > analysis involves a before and after pictures comparing the FSK > spectra from the general release firmware (representative of most > radios, to the best of my limited knowledge) and the bandwidth-reduced > firmware. > I've also included some analysis using a 300 Hz "roofing filter" to > measure the noise floor at different dial offsets from the transmitter > to give and idea of what it "feels" like when it is QRM. There are a > few people who operated WPX and and other contests with this firmware, > and I am sure they could tell of their experiences on the transmitter > side. > > http://www.frontiernet.net/~aflowers/k3beta/ > > While on the subject of clicks, spurs, and other nasty things, I also > would encourage people to have a look at N2QT's question on p. 55 in > the April QST and WB1GCM's (at ARRL Lab) response, which also address > this and some other issues around RTTY keying. He distinguishes > "clicks" that result from the waveform from the other bad things that > can happen with broken audio signal chains. This is an important > distinction to keep in mind. > > Enjoy! > > Andy K0SM/2 > _______________________________________________ > RTTY mailing list > [email protected] > http://lists.contesting.com/mailman/listinfo/rtty ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
