On my boards, that coax feed coil is an ERSE FoilQ. It is availble in 16 gauge at 0.15 mH. The OEM aircore one is 18 ga but I cannot tell it hurt anything to increase the gauge and was OKed by Tom Thiel. Then again, I’ve changed so many parts at once that it is near impossible to say where the biggest improvements came from. Well, I did change the resistors to Mills as a first step, so I know what those add to SQ. I will soon compare the Clarity CSAs with and without bypasses on the coax feed.