On Tue, May 09, 2023 at 03:06:34AM +1000, Adrian via wsjt-devel wrote: > On 9/5/23 02:49, Jim Brown via wsjt-devel wrote: > > > #3 is bogus. > > How would you know ? You lack the technical ability..
I'm not an AES fellow, but as another audio 'expert' I can only confirm that #3 is complete bogus. Even if the audio HW is usually the most crappy part of most PCs, it's not that bad that generating signals in the 1.5 to 2.5 kHz range would have less 'digitisation nonlinearities' (whatever that means) than anything outside that range. If there are any nonlinear effects, that would be mostly due to the complete mismatch between a typical PC headphone/line output (a few hundred mV) and a typical rig mic input (expecting maybe a few mV). What you need to avoid that is a passive attenuator (two resistors) between the two, allowing the PC audio output to operate at its normal level while avoiding overload on the mic input. Also relying on the rig's filters to remove any harmonics is just bad practice again. There shouldn't be any harmonic content in the audio to start with. The really hilarious thing about this whole thread is that it is just the result of an implementation detail of WSJT - using audio signals as the interface between a PC and a rig. In these days of SDR hardware, I'd expect a rig to both output and accept digital complex-valued baseband signals. Even the cheapest SDR hardware can provide and handle at leas 1 MHz bandwidth with a near perfect flat frequency response. Just my 0.02 Euro of course. _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
