Readers from the future! If you see this email but no replies, assume that it worked. :-D
It worked! I am now generating BFO from CLK0 and the BitX40 is receiving and transmitting just fine.
However, when I set CLK0 to bfo_freq exactly, the IF filter was passing REALLY HIGH audio (about 1.5kHz high as we'll see).? So I adjusted bfo_freq down by 1.5kHz (after a bit of playing with it to find the right sound) which put the IF pass-band in the right place, but now the VFO dial was low by 1.5kHz? Huh?
I have a working radio by keeping bfo_freq at its original value (11998000L) for the VFO frequency calculations to be correct, but setting the BFO frequency by subtracting out 1500 from the "bfo_freq" like so:
si5351bx_setfreq(0, bfo_freq-1500);
Anyone understand what's going on here?? I would expect any change in the BFO frequency to need to be applied to both the BFO and VFO calls to si5351bx_setfreq().
My intent is to add an IF shift function:? Use the A6, the one remaining analog input, with another voltage divider pot, to move the BFO/VFO +/- 500, maybe 1000Hz. I have this on my FT-920 and it can be really handy in a crowded band.
Smitty, N6MTS