Having realised that a radio powered by a PP3 is quite adequate for reliable activating, I am now looking at further weight reduction opportunities. Just how light can a viable HF antenna be made - and what materials were used? Just for starters, my lightest HF antenna is a longwire for 40m which, complete with radials and a back guy for the mast, weighs in at 300g. I suspect that I could use thinner wire to save weight. Ideas?