I cannot find the thread but it spoke to the impedance difference of a handheld. The icom in my one holer works great but the sportys handheld in my buddies luscombe through an intercom is poor. The above mentioned thread referred to Ron wanajant's fly baby site. Sorry about slaughtering your name Ron. The site has a link for a company that builds an inline gizmo that changes the impedance. My buddy bought it. Very reasonable. I tried it tonight and it really increased the volume. Had to turn it down. Open cockpit. Could not recommend it more.
WILL
WILL