Si5351 again

Continuing with the filter test saga from yesterday:

https://wb9kzy.blogspot.com/2025/08/self-inflicted-wound.html 

I dug out the Si5351 breakout board on a solderless breadboard connected to an Arduino Nano.

After a few misadventures with the Arduino IDE and the Skyworks Clockbuilder I was able to generate this:

Unfortunately it is wrong, I wanted 27.005 MHz (CB channel 4) but punched in 27.05 instead and of course the silly software did exactly what I punched in :)

Re-doing the frequency with Clockbuilder I got this:

This is after being peaked through a double tuned LC filter, yikes !  

Finally able to peak the filter - but while I was wrestling with the Arduino and Clockbuilder I remembered the NanoVNA:  isn't filter work the exact reason for having a NanoVNA ?  And doesn't it already have an easy to program Si5351 (or equivalent) inside ?

I tried listening to the 27.005 carrier on the K2, double yikes !  Really sounds terrible (although strong) but hopefully the noise is due to the solderless breadboard, USB power from the laptop and long leads / lack of shielding ?

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm