Here is another antenna tuning conundrum. This morning I hoisted up a 72-foot random wire (and deployed a counterpoise). My calculations suggested it should tune great on 30 meters (almost exactly 3/4 wavelength) but poorly on 40 or 20 meters (close to 1/2 wave multiples). Here is what I found in terms of SWR of the untuned antenna as determined by my NanoVNA and what I observed when I tried to achieve a good SWR match with my KX2 automatic antenna tuner.
30 meters - VNA SWR = 2.3; KX2 can tune to SWR = 1.0 : NICE! 20 meters - VNA SWR = 13.17; KX2 can tune to SWR = 1.0 : NICE BUT SURPRISED! 40 meters - VNA SWR = 4.4; KX2 can only tune to SWR = 4.4 : TOTALLY BAFFLED - WHY?
