I hear Futaba make a nice radio. All kidding aside, I think you should make an effort to contact Airtronics for this one. It may be something to do with the SANWA buddy box just not being compatible in that configuration. I truly don't know. Sorry. If you call them or email, have ALL of your information above available.

Airtronics Inc.
1185 Stanford Court
Anaheim, CA 92805

Phone: 714-978-1895
Fax: 714-978-1540
E-Mail: [email protected]