Small Receiving Loop Antenna with Matching Variable Capacitor - Test with NanoVNA

Описание: This is the small loop receiving antenna I've been using with the the SDR circuit experiment. There is already a video with description and tests on this channel:    • Small Loop Antenna test with NanoVNA  
In short, it is a square loop with 50cm side, made with 75 ohms RG59 coaxial, which shield was cut right at the center. The separated shields are connected at output ground, the inner conductor ends are connected to a variable capacitor for tuning (~5 MHz to ~9MHz). As I got another variable capacitor (    • Variable Tuning Capacitor from AM-FM radio...   ), it is time to try a simple modification by including it as an impedance matching capacitor. The impedance matching capacitor is inserted in series with the output. Another change is the P2 conductor/C1-2 end connection to ground. This is supposed to improve balance, so worth trying. Both variable capacitors are from portable AM radios and adjustment is not exactly smooth. The impedance matching capacitor would definitively benefit from a reduction gearbox of some sort, but works as intended.
Tests were made with NanoVNA vector network analyzer.

Thanks for watching.