I recall there are a few older threads on antennas. I think one said not to use a handheld antenna, or maybe the radio manual said that, I'm not sure, but it's easy to check. For bench testing a friend uses a home made dipole antenna in his ship, which I also tested. Just search the web for "home made dipole antenna". I tested one flying to root cause a antenna problem and it worked pretty well. You only need coax of the correct ratings and single conductor wire or metal rods.