Using a cheap toroid core from Jaycar I made a simple 1:1 balun. Side effect of this balun, bands sort of tune in, but it’s easier without the balun to match with a tuner. This could be that using a balun effectively stops the antenna at the point of the balun, while, without it, the RF can make use of the coax as part of the antenna. It could also be that the balun us not designed for much over 2MHz, but, for a balun, this is not significant.