I've just been listening all evening with a big smile on my face :*) This is beautiful. Having the LF audio seems to make the entire spectrum sound better. Even QRN is more pleasant to listen to. Thanks Elecraft! What took so long? Why was bass chopped off in the first place?
Steve N4LQ n...@carolina.rr.com ----- Original Message ----- From: "Paul Christensen" <w...@arrl.net> To: <elecraft@mailman.qth.net> Sent: Friday, September 18, 2009 10:40 PM Subject: [Elecraft] K3 Audio Response - Version 3.33 Firmware >I have attached links to three .JPG images of the K3's audio response as > measured at > the headphone jack with SpectraPlus FFT software. Response passband was > normalized for both modes. SSB > is measured through the 6K filter, and CW through the 8-pole 2.8 kHz > filter. > However, V3.33 SSB was taken with Fc = 1.35. > > It would have made more sense to capture the responses such that three SSB > plots would overlay on one graph and three CW plots on a second, but that > took too much time in waiting for the firmware to load between plots. > Still, you can see radical differences between firmware versions in the > kinks below. Rx Band-1 EQ seems operational now too :-)). > > http://216.229.20.37/images/K3-V325.jpg > http://216.229.20.37/images/K3-V330.jpg > http://216.229.20.37/images/K3-V333.jpg > > As you can see, CW with V3.25 has the strongest low-end response relative > to > 1 kHz, but that can be compensated for with the first two EQ bands. Even > as > it is, if you draw a horizontal line mid-way through the V3.33 plots, that > represents roughly +/- 2.5 dB from 20 Hz through 3.5 kHz. Not too shabby > for a > communications receiver. > > As a further experiment, I just added 3 dB to Rx bands 1-3 and the > response > is now essentially +/- 0dB between 20Hz and 3.5 kHz in SSB through the 6K > filter and Fc = 1.35. You can lay the ruler flat on the response. > > http://216.229.20.37/images/K3-V333-EQ.jpg > > Paul, W9AC > > ______________________________________________________________ > 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 -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.105/2380 - Release Date: 09/18/09 07:49:00 ______________________________________________________________ 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
