Dutch amateur radio station
For the mobile operation in the summer holidays i use a vertikale multiband antenne from Diamont the VX-7CX it is working on 5 HF bands.
I mounted the antenna on the bicycle rack of mine good old T3 VW camper bus.
If you take the size in account, only two meters long, the VX-7C is working quit good. One of the things is that the bandwith of the antenna is limited to a few 100 KHz, this limit was the reason to thry out something else.
And of course the fun to make something.