operating from a high and windy hill at the weekend, a small kit bag with the whip antenna for my FT817 blew away (plus a couple of leads). I was going to make up a temporary antenna with a piece of copper wire and have tried to calculate the resonant length for 145.500MHz. At the risk of embarrassing myself 17cm is what I have come down too. Any suggestions on the correct length (I can trim with the SWR meter) or on a home brew replacement design. Lightweight preferably.