Richard/Allan .... that's about right - but you cheat. You don't have a full wavelength aerial, you make it quarter wavelength and then hope for the best - or add an aerial tuner where you can artificially tune it to "full wavelength" using a coil to artificially lengthen the aerial.
Works fantastically well as a di-pole ( s.o.p. as a young Marine sigs found out !).
Trouble is, come dusk, when the ionosphere starts playing up, the signal goes all "out to lunch" a tadge ! So that will - up "I'm Sorry, I Haven't A Clue" !