Good that you are moving to the CLK0 BFO scheme, looking forward to that. ?Once both BFO and VFO are generated from the Si5351, then all errors in operating frequency are proportional to the error in the 25mhz reference oscillator. ?The current calibrate scheme adds an offset to get on frequency within the 40m band, ?the new firmware can instead perform the correction as a multiply using the etherkit library ppm correction factor. ? A calibration performed at 7.3mhz should still be on the money at 7.0mhz. ?And at 30mhz, for that matter. ?Could short across the BFP and calibrate by zero-beating to one of the time standards like WWV.
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On Thu, May 25, 2017 at 04:58 am, Allard PE1NWL wrote:
Moving the LO frequency from 5 Mhz to 19 MHz, and shifting the BFO frequency a few kHz down (for LSB) eliminates this problem. This has already been done by several experimenters and I'm planning to include this in a future raduino version.
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