Ozipole
From The Unofficial FT-897 Wiki
A friend of mine bought the Ozipole a while ago. I made one from scratch that seems to work well. I tied mine to the top of a swing ball game whilst staying in a caravan. I pluged in my 897, tuned the Ozipole for 20m and ended up talking to Cyprus with a competition 59.
These aerials use plastic conduit with a T junction in the centre for mounting on a pole. A smal project box bolts on to the back of the T peice in order to mount the socket you connect your coax to. I opted for a slightly bigger box and mounted the T peice inside the box (hot glue works wonders) and drilled holes in either end of the box, making the box and the T peice a bigger, stronger support. This also seems to stop the elements from drooping as much.
UPDATE: I got a bit of a shock yesterday (24th May 2009). I was having a short break at a caravan in Creswell (NE coast of England) when I made a 57 contact with 9K2MU (Kuwait). That's a 3,000 mile contact on 20m, 50 watts into my Ozipole which was about five metres high at the time. I guess they work then! :)