A New Line of Transceivers ~ DifX
Transceiver Architecture 2.22
Have You Ever Wondered?
Arduinos and Si5351 PLL Clock Generators are inexpensive (well depends where you live); but for around $20 (US) you can purchase a ProMini and a si5351 Clock Generator. I have not seen many designs where two Arduino's and two PLL clock generators are employed. So why not? Yes you will hear from the lurking illuminati that you don't need to use two but has any one really explored the possibilities opened up by such an approach.
Let us think "Out of the Box" for a minute. Suppose we take a device like the Pro-Mini and loaded that with code so that CLK2 would provide the injection frequency for a second mixer in a dual conversion transceiver (the 1st conversion would be an up conversion to say 45 MHz).Thus the second conversion would be to the IF frequency and CLK0 would provide the BFO injection frequencies. You got that OK?
Now think for a minute of a two position switch mounted on the front panel so that one position would be to select USB, the second position would be for LSB. You might even have a second encoder with a PB so that by depressing the encoder push button you could have pass band tuning limited to the range of separation between the USB/LSB frequencies. Pretty cool.
Now about the second Arduino and PLL Clock Generator. Suppose that this time for the up-conversion we use the Si570 controlled by an Arduino Mega. The use of the Si570 would cure the gaff from the EMRFD Illuminati about phase noise and would use a true encoder and not a pot like in the Minima. I am thinking with the Mega you would have more digital and analog IO so that controlling band pass and low pass filters would be unencumbered by pin limitations. A bigger display (and more programming space in the Mega) would let you display to your hearts content. The two PLL Clock generators will also address the naysayers who complain about the spill over onto the third clock. The upper frequency limit of the Si570 is about 5X the Si5351 so other possibilities here.
So maybe it is time to add a few more Arduino's and PLL Clock generators in our rigs.