Re: IQ from Sound Card - missing ppm @elektor_sdr_shield #arduino
There is a good reason for this. There are two oscillators that need correction. And the correction process is a nasty dance when you do not know what has to be corrected for the error you are seeing. At the very least you need two widely separated frequencies that are very well known, say 5 MHz and 20 MHz at appropriate times of day they are more or less stable without ionospheric variations. The sound card error is the same for both frequencies if you leave WWV signal at the same spot on the display. So adjust the Shield's frequency with any trimmers it may have so that both frequencies show the same offset. Then adjust the sound card, somehow, to remove its error setting the offset to zero.toggle quoted messageShow quoted text
It's exhausting (and annoying) just to describe it let alone do it.
On 20200405 08:15:34, Jean-Marc Paratte wrote:
On Sun, Apr 5, 2020 at 03:59 PM, prog wrote: