A Pico2 connected up to my TinySa with an inline 20 dB PAD.
I had to raise the core voltage up to 1.5V to get the VCO,PLL,Clock driver to keep up.
Its alive, and toggling at 1.21 "Jiga" Hertz,
Sadly there is no chance the entire chip will run at 1.21 GHz. However some of the forums online suggest the rp2350 has some potential for overclocking.
