Does somebody know the brand/model of the 3 ports directional coupler used in this video: https://www.crowdsupply.com/lime-micro/limesdr/updates/vna-pihpsdr
It seems a Mini Circuits one but I can’t read the model. I would like to read the specs/features/price/shipping.
Actually, I would prefer to get a link to some suggested design to build one for HF usage < 30 MHz.
I’ve found some designs on the web but all have 4 ports instead of 3. I’m not an expert, but would like to build one since I already got good results with my bandpass filter and TFD antenna.