Mike, Did you checked what happens in your computer(s) in following combinations:
15 s wav, Flatten, Low sidelobes 15 s wav, Flatten, Most sensitive 15 s wav, non-flatten, Low sidelobes 15 s wav, non-flatten, Most sensitive 45 s wav, Flatten, Low sidelobes 45 s wav, Flatten, Most sensitive 45 s wav, non-flatten, Low sidelobes 45 s wav, non-flatten, Most sensitive Only one but last one generated those multitude sidelobes in mine! For sure it is not clipping at top of amplitude. Clipping would generate harmonics not sidelobes. Could it be a spectrum calculation overflow in the Low sidelopes process? Mike have your made a over the air measurement where you have guaranteed that no “clipping” happens at receiver system? My thermometer goes to 84 % with your *.wav files. I fully agree Bill that most transmitters have other noise components higher than those. 73, Reino OH3mA From: Bill Somerville [mailto:g4...@classdesign.com] Sent: 15. helmikuuta 2021 15:32 To: wsjt-devel@lists.sourceforge.net Subject: Re: [wsjt-devel] Clipping Mike, the "nastiness" you refer to is more than 65 dB down. As far as we have been able to determine it is due to either Windows or VAC. My money is on Windows since VB Cable exhibits the same behaviour, although that is not conclusive. Note that 65 dB down is below the distortion added by almost all transmitters. We are pretty certain Qt is not the cause since when the Pwr slider is at 0dB Qt does nothing with the samples other than copy them to the Windows MME audio buffers. 73 Bill G4WJS. On 15/02/2021 13:23, Black Michael via wsjt-devel wrote: It's not just the waterfall....that nastiness gets transmitted too. Mike W9MDB On Monday, February 15, 2021, 02:53:44 AM CST, Reino Talarmo <mailto:reino.tala...@kolumbus.fi> <reino.tala...@kolumbus.fi> wrote: Hi Mike and Bill, I looked those *.wav files using v2.4.0-rc1 and noted interesting presentation difference, when I had Flatten activated or non-activated. Especially the waterfall display changed a lot. It was difficult to see those multiple sidebands in non-flatten display totally independent of gain and zero settings. In spectrum display I can see the carrier and weak sidebands at 310 Hz or so. In both flattened and non-flattened spectrum other than the 310 Hz sidebands are really weak some are just a pixel or two and others none. Could the flattening do more than modify the frequency amplitude and be an additional reason for a bad waterfall display? 73, Reino OH3mA
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