Good morning Dr Jim,
I tried one with my FT817 many years ago in the UK (I was born and raised in the UK) an was completely disappointed with it. Did a couple of "local" contacts on 20m, added a counterpoise, to the radio ground screw, but not much improvement. My 2c worth for what it's worth, stick with the wire.
Be blessed and have a grand day,
Wayne - NQ0RP - G0JJQ - G6UIT
QRP - EFFICIENCY AND SKILL, NOT POWER.
God Bless from Wayne Dillon - NQ0RP
Fate whispered to courageous "You cannot withstand the storm"
Courageous whispered back "I am the storm"