I've been following this thread and have to attest that Bill's suggestions work. But why?
As a test I put the Flex in USB at 8khz bandwidth. I limited the response of my RE27 also to 8Khz. I listened to the raw audio from the mic and it sounded great. I passed it through the 5k and it sounded muddy. I then passed it through a 950SDX and it also sounded muddy. Next I applied TX equalization, which follows Bill's technique. Both radios sounded great. So my result is that TX equalization works, but why is it needed? And this is not true just for the Flex. It is true for basically any radio you test with. Finally, it does not depend on the TX bandwidth, because even when I have the Flex open to 8khz, the muddiness is still there. I hope someone out there can explain this enduring mystery. 73 Ed W2RF On 3 Jun 2008 at 18:21, Bill Winkis wrote: > Wow ... this discussion should be simulcast on the Enhanced SSB > reflector... > > Well, one of the approaches to kill the muddiness, is a technique that has > been employed in recording/broadcasting over the years.. > > 1.- There is a magic spot in everybody's voice that will increase clarity > and pull down the lo-mid darkness (Muddiness) ... its different in > everybody's voice but can be found around 160 Hz .. use a narrow "Q" and an > amplitude reduction of 6-8-10 dB. Throttle around 160 till you find your own > personal spot.(mine is at 148) > > 2.- To increase the clarity, add 6-8-109 dB at 3730 Hz, now its not the 3720 > we are concerned with ... its the magic 2d harmonic at 1865, with a long > "Q". (You want clarity..here it is..!!) > > 3.- Now put a low end cut of 10 dB beginning at 65 Hz going down and a > 6-8-12 dB high end cut at 3200 Hz going up. > > 4.- As a option for polish and fullness add 3-6 dB at 80 Hz with a sharp > "Q"... and throttle for the sweet spot.... > > You would be surprised a the number of studio voices this trick of 160 and a > 3720 harmonic saved from the cutting floor....!!!! > > -Bill > [EMAIL PROTECTED] > > http://www.kc4pe.com/amateurshack.htm > > > ----- Original Message ----- > From: "Ahti Aintila" <[EMAIL PROTECTED]> > To: "Jeff Anderson" <[EMAIL PROTECTED]> > Cc: <flexradio@flex-radio.biz> > Sent: Tuesday, June 03, 2008 5:37 PM > Subject: Re: [Flexradio] The inherent muddiness of typical > amateurtransceiver > > > >>>> On 6/3/08, Brian C <[EMAIL PROTECTED]> wrote:> > >>>> > >>>>> That said, everyone knows wider bandwidths should not be employed on > >>>>> very crowded amateur bands, nonetheless, the key to intelligibility > >>>>> and fidelity is b a n d w i d t h. > >>>>> > > Hi all, > > Actually, IARU recommends max. bandwidth of 2700 Hz on ham bands below > > 28 MHz. If you obey the rules and don't want to drown the information > > content of your transmission into the mud, you better equalize your > > signal in a smart way. I apologize for referring again to these two > > old and good articles that every phone (SSB) operator should read and > > understand: > > http://kotisivu.dnainternet.net/ahti/sdr-1000/filtclip.pdf > > http://kotisivu.dnainternet.net/ahti/sdr-1000/speechproc.pdf > > > > Of course those articles discuss analog signal processing, but the > > same ideas apply to the DSP radios as well - actually much better. > > Study the TX equalizer and compressor setup possibilities of PowerSDR > > of Flex and K3 of Elecraft. It is really a pity that the both > > manufacturers have not given any recommended (default) SSB equalizer > > settings along the principles discussed in the given articles. > > > > Ahti OH2RZ > > > > > _______________________________________________ > >> FlexRadio Systems Mailing List > >> FlexRadio@flex-radio.biz > >> http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > >> Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > >> Knowledge Base: http://kb.flex-radio.com/ Homepage: > >> http://www.flex-radio.com/ > >> > >> > > > > _______________________________________________ > > FlexRadio Systems Mailing List > > FlexRadio@flex-radio.biz > > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > > Knowledge Base: http://kb.flex-radio.com/ Homepage: > > http://www.flex-radio.com/ > > > > > > > _______________________________________________ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kb.flex-radio.com/ Homepage: > http://www.flex-radio.com/ > _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
