W4TV wrote:
> My source is Elecraft: www.elecraft.com/K3/K3_8_pole_plots.htm > > Look specifically at the last two plots which show: > > KFL3A-400 KFL3A-250 > -6 dB 435 Hz 370 Hz > -60 dB 935 Hz 785 Hz > SF 2.15:1 2.12:1 > > INRAD do not publish the curves for the Elecraft (or Yaesu > 8215 KHz) 250 Hz filter. However, they do show the curve > for the 8830 KHz (Kenwood) version of the same filter and > it shows a similar percentage bandwidth (367.5/845 Hz at > -6/60dB). > NI0C responds: I'm still wondering what the tolerance is on such published curves. > Did you run those tests in a Data mode or with the CW pitch > set to 800 Hz? If not, the low frequency skirts will be > sharpened significantly and the measured bandwidth will > less than the roofing filter. With a CW pitch of 560 Hz > I measure 10% less bandwidth than in DATA (CF = 1500 Hz or > 2210 Hz). If I reduce the pitch to 300 Hz, the measured > bandwidth is further reduced (due to the DSP filter's low > frequency cut-off). > > 73, > > ... Joe, W4TV NI0C responds: My testing was done in CW mode with the pitch in the low 300's (320 Hz, as I recall). So, when I repeat the tests, I'll vary the pitch and see what happens, say 300 Hz, 600 hz, and 800 Hz. 73 & Thanks, Joe, for your info! Chuck Guenther NI0C ______________________________________________________________ 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
