Re: memory manager/alignment


AndyH
 

    One more piece is to identify the exact frequency of the 25 MHz (or 27 MHz) crystal used to feed the SI5351.  This requires programming a Nano with the calibration sketch, letting the Raduino get up to operating temperature, and then measuring the output from the Raduino with a signal counter.  The actual frequency is entered into the Raduino software and it's recompiled and burned into the Nano that will run the Raduino.

https://github.com/etherkit/Si5351Arduino/blob/master/examples/si5351_calibration/si5351_calibration.ino
   
The actual crystal frequency is entered into the Raduino code.  This example is from the CEC firmware, V1.2.  It's from ubitx_si5351.ino line 55:

// If using 27mhz crystal, set XTAL=27000000, MSA=33.  Then vco=891mhz
#define SI5351BX_XTAL 25000000          // Crystal freq in Hz
#define SI5351BX_MSA  35                // VCOA is at 25mhz*35 = 875mhz

   There may be other ways to do it, but this is the method I've used.
 
     Best,
     Andy


On Fri, Oct 16, 2020 at 11:38 AM, Mitchel Rought wrote:
is it possible to change the display frequency through memory manager, after alignment this radio is slightly off, web sdr 7.050.000, this radio 7.049.700, I realize it's not much but still bothers me

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