Both PNA and Y-factor measurement options are sensitive to oscillations, and external sources making its way into the signal chain. Y-factor measurement depends on VSWR, and for sub-dB measurements, the ENR of the source is affecting the measurements, and can vary with calibration year per year. AFAIK accuracy with the newest USB-C sources from Keysight is in the range of +/- 0.2 dB NF with a known DUT (I have had the luxury of using a PNA and Y-factor equipped NFA side-by-side). PNA measurements are can be difficult as compression will affect the measurement.

Please do livestream!

Agree with the previous posts, dont change! Been reading and enjoying the microwaves101 content for 5 years now, and I love the relaxed format and hands-on approach to the sometimes quite difficult world of microwaves.

If you are up to do it yourself with some guidance I have seen Dunsmore himself answer repair-related questions over at the EEVblog forum.

Surtec650 for RX-purpose waveguide works just fine. Scratch resistance is not on par with proper silver plating though.

Maybe some shop using cubic boron nitride grinding wheels could do it