An Air-Spaced Variable Capacitor With Brass Vanes

I think I might be closing in on the ideal variable capacitor for a VFO.  This arrived in the mail yesterday from an eBay seller: The capacitance swing is 9-50pF with wide gaps between the vanes.  Rotation is fairly smooth, though the bearings could use a re-lube. Brass is a good metal for the vanes, […]