Two years ago, a very interesting discussion of balanced feedline length for 44ft doublets occurred within this thread: https://reflector.sota.org.uk/t/seven-sota-antennas-compared-using-wspr-on-a-summit/15635/62
I was just going over it while building a new 44ft doublet and I’m suddenly confused by DL6GCA saying you must avoid feedline lengths that are a multiple of electrical half-wavelength. This doesn’t readily make sense to me. A half wavelength feedline simply delivers the same impedance at the antenna feedpoint to the end of the feedine. I would think instead that what you actually want to avoid are feedline lengths that transform/change the feedpoint impedance to a very high value at the antenna tuner terminals (source), thus presenting a load that might be impossible to match. This would require something like a Smith chart calculation for each frequency and feedline length to check impedance at the source, not a simple calculation of electrical length of feedline.
Do I have this right or wrong? Comments appreciated.
Thanks & 73,