You've probably heard amateur radio operators describing how when some stations are very strong, or propagation is very good, you could "probably work them on a coathanger". (Another version of this says you could load up a string of wet spaghetti and you would work them!) Well this video shows the signal of RI1ANF, Oleg, who is based in South Shetland Islands in Antarctica. I was listening at the time on my Icom IC-706 Mark II in the car, which is attached to - wait for it - a quarter wave whip antenna for the 4 metre (70 Mhz) band.
That's right!! He could be heard without any problem on this small antenna!
I had earlier worked EW8A in Belarus on 17m CW using just this antenna, which is probably smaller than a wire coathanger stretched out !!!!!!!