tinyPFA – new Nanovna-H4 arrived

TinyPFA is firmware from Erik Kaashoek for NanoVNA-H4 hardware for accurate measurement of oscillator and clock source stability.

I was so impressed with the possibilities of the project, I purchased a new Nanovna-H4 v4.3 a couple of weeks ago to dedicate to this application.

Anticipation got the better of me, and I put tinyPFA onto my existing Nanovna-H4 v4.3 to evaluate it, and was not disappointed.

Anyway, the recently ordered device arrived.

Above, the new tinyPFA at work.

Commissioning the new hardware involved these steps:

  • test it on the supplied firmare, inspect an uncalibrated sweep on a 50 ohm termination, calibrate it 1-101MHz and inspect some sample sweeps.
  • uncase the thing, inspect the PCB for defects, remove the shields and carefully check the soldering of the SMA connectors;
  • fix the SD slot: NanoVNA-H4 v4.3 – improving the SD card slot;
  • fit SMA connector savers, 20dB SMA pads, BNC(F)-SMA(M) adapters;
  • calibrate Vbat and label the case;
  • replace the case screws with M2x12 304 socket head self tapping screws;
  • load current tinPFA firmware and test.