On 2 Dec 2019 at 10:34, Frederic Beaulieu wrote: > You can see in the link below the noise at TX start: > > https://youtu.be/peVSAZQ08yU<https://can01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2FpeVSAZQ08yU&data=02%7C01%7CFrederic.Beaulieu%40trilliant.com%7C2ae827da836a4ccdcdae08d77718bd46%7C4f6fbd130dfb415085c3d43260c04309%7C0%7C0%7C637108820461481425&sdata=TtCmElZ6kEFjmog2RWB%2F6jm%2FQdKOiLLcJmHPd0mEbkY%3D&reserved=0> > > which cause power overshooting at the beginning of the timeslot. > > 73,
Hello Fred (and all), I suspect that the 'overshoot' or 'splat' of noise you're seeing at the start of your transmissions might be an Icom-specific artefact - under certain conditions I observe the same effect with my IC-7610, which is fed with analogue Tx audio from an external codec via the ACC1 rear-panel socket. When I use the WSJT-X 'Tune' button to key the Tx and send an audio tone from the PC to the rig, via the external codec and the ACC1 socket, I observe the short-duration burst of signal, be it noise or whatever, on the rig's spectrum scope and waterfall. This happens when the rig is connected to a dummy load and generating only a Watt or two of RF output so it's extremely unlikely that the cause of the unwanted burst of signal is RF somehow getting back into the audio chain. The burst of signal appears to extend to approx 1kHz either side of the centre frequency on the rig's spectrum scope and waterfall; when I listen to the monitored Tx audio out of the rig I don't hear a clearly-identifiable burst of any sort of noise etc, but the onset of the 'Tune' audio tone does sound very 'hard' and abrupt. I observe, and hear, a similar effect when I stop the 'Tune' operation and the rig returns to the Rx state - the cessation of the audio at the end of a 'Tune' transmission again sounds very 'hard' and abrupt. Interestingly, I only very occasionally observe the 2kHz-wide burst of noise or whatever on the rig's spectrum scope and waterfall when WSJT-X is Tx'ing normally; perhaps the fact that I've got my IC-7610's Tx delay set to 15msecs (on both HF and 6m) and the WSJT-X Tx delay set to 100msecs is having a bearing. A question for Bill and the developers - is there any form of shaping of the leading and trailing edges of the audio waveform generated by WSJT-X when the 'Tune' button is operated? If there isn't then I wonder if the unwanted, albeit short-duration burst of signal, which doesn't appear to have any adverse effect overall, is akin to a CW key-click caused by too steep a rising and trailing edge on the audio waveform. --- Martin, G0HDB _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
