I'm very curious how well the i2c writes into the si5351 do.
Looking forward to your notes on how clean you can get the signal.<<
Jerry,
All you need to test the signal generation is a raduino.? There are a few things to be aaware of as its clocked at 25mhz
and the there is no amp after it but the code after matching the LCD lines runs.? Of? Encoder, An Uno or nano and a 5351 board.
Some of you speculation is about how the si5351 works and much is not given away.? The PLL VCO is controlled
by the PLL divider or multisynth and the VCO tracks that.? The VCO based on my PLL work should settle fast but
you have some long counter chains and that is a factor.? Then you have the overriding thing that moving 8bits via SPI
even at 800khz takes about 11us.? That last item is the fastest you can change any parameter of the 5351, 1 byte 11us.
Putting a varactor on the crystal would create FM, you don't want that.? You would have to process the mic input to
a D/A output and then your guessing on frequency as its in the analog realm.? then the output of the 5351 will multiply
that (crystal to VCO then divide to output frequency).? On a good day that would be band limited.
The use of a mixer, really?? Mix the 5351 and I presume audio, then a crystal filter as you have both sidebands.
Again that is a ground up bog standard filter SSB.? The EER part could be added but if you get the phasing
wrong the sideband spurs will give a IMD of terrible.
Allison
