Dave Baxter wrote:
Personally, I wouldn't bother with any high accuracy clock/oscillator for the SDR, unless you can also synch the AD sampling clock in the soundcard.
The SDR-IQ, SDR-14, Qs1r, Perseus and the HPSDR project do not rely on a sound card ADC to sample any signals..... The RF signal is directly sampled at RF, with sampling rates up to 122.88 MHz (depending on the model), then it is frequency-shifted, then downsampled by the firmware in the accompanying FPGA. Then the downsampled stream is sent to the PC via the USB 2.0 port. The software on the PC receives directly digital data, no pesky sound card is needed to digitize it. So the _only_ factor affecting the frequency calibration is the clock of the RF ADC. 73 Alberto I2PHD _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
