Hi Steve
I am currently using a Popovic antenna for 2m, it is also a duel band so will cover 70cm. You can make this very easy. I made mine out of welding rods and connected to a choc block, so all can dismantled very easy for portable work. here is a link for pics. http://www.pa2old.nl/page.php?id=30
and just Google “popovic” images for dimensions in English. You will not be disappointed, works a treat!
73
Dave, ZL1DCO