I want to construct an antenna competent on the 160m band, but I haven't got quite enough space, here's my thinking, please let me know if/what you agree/disagree with.
I have a plot of land with three sides closed totaling 56.5 metres. At a typical velocity factor I'd need a little under 80m, maybe 77m, so I found this article:
The author claims to have constructed a dipole with cheap coax at a velocity factor of .66, making the antenna 53m long, which I can fit, and other references cite lower velocity factors for RG85 coax as low as .535, so there might be a lottery as to whether you get the RG85 A/B/C variant, and I might have to do some trimming on the antenna to find the correct resonance if the Amazon listing says RG58 but means RG58B for example, but if the velocity factory is <~ .66 I'm good for length, though I might have to turn an end at 90 degrees for a few metres worst case.
If you inspect the link above, it shows the feed point in the centre connected only to the coax centre conductor, and the outer ends shorted together, the author claims to have QSOs from Brazil to Italy and Bulgaria on his first night.
I've given up on quarter wave end fed because the grounding system I would need is too much trouble, and 1/2 wave dipole doesn't need grounding, also the QWEF would need to be 40m above ground which I can't do... am I correct in saying that the dipole I propose could be 5-10 metres above ground varying along its length without much problem?
How difficult would it be to fashion or buy traps to install in the antenna to make it comprehensively multiband?