Joe, The old MP dsp demod is a bit different from the MKV, as far as I know.
Given the MP. If I shift the IF in the MP to the opposite sideband, retune with the dial, then the signal is there just like it would be on the right sideband. Then tap the DSP demod and 'presto' : the signal is inaudible. (The S-meter still moves but that is because the dsp demod is outside the AGC-loop). Maybe the difference in suppression level is in the AGC since the MP still has reduced gain when you tap the dsp demod, which is different from the K3 of course. It just struck me that the sidebandsuppression was not so absolute in the K3. Sideband suppression is, I think, another algorithm than passband filtering. But I'm not an expert in DSP SW. 73 Arie -----Oorspronkelijk bericht----- > Just for comparison, using the DSP demod on my old vintage 96 > MP. It suppresses the opposite sideband perfectly. That is 13 > years old DSP technology and firmware. You must have an exceptional MP ... my MK V would certainly exhibit "opposite sideband" response in CW if I moved the PBT very low in frequency and then tuned to the other side of the carrier. I can't think of a single radio that had unconditional single signal response if the PBT (or filters) were adjusted so they provided a response on the "image." 73, ... Joe, W4TV > -----Original Message----- > From: Arie Kleingeld PA3A [mailto:p...@xs4all.nl] > Sent: Saturday, September 19, 2009 6:31 PM > To: li...@subich.com > Subject: RE: [Elecraft] K3 Audio Response - Version 3.33 Firmware > > > Joe, > > With DSP demodulation the opposite sideband suppression > should not be a problem. > > Just for comparison, using the DSP demod on my old vintage 96 > MP. It suppresses the opposite sideband perfectly. That is 13 > years old DSP technology and firmware. > > No reason why a K3 could not match that. But it does not. > > > 73 > Arie PA3A > > -----Oorspronkelijk bericht----- > Van: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] Namens Joe Subich, W4TV > Verzonden: zaterdag 19 september 2009 17:06 > Aan: d...@w3fpr.com > CC: Elecraft@mailman.qth.net > Onderwerp: Re: [Elecraft] K3 Audio Response - Version 3.33 Firmware > > > > > > Hearing a bit of the opposite sideband is a natural effect > of using a > > very low Shift/Lo-Cut setting. No matter how straight > sided the DSP > > filter may be, it does have a finite slope to it (if it did > not have > > slope, it would ring like crazy). > > The DSP effect would be at audio. The "opposite sideband" effect > is due to no longer "fixing" the corner of the roofing filter 200 > Hz away from the carrier point. Remember, audio frequencies are > imaged (folded) around the carrier. > > The DSP works the same whether audio at 200 Hz is above or below > the carrier. > > 73, > > ... Joe, W4TV > > ______________________________________________________________ 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
