I have two KWM-1 units. One has a PA SCREEN off-on switch mounted on the PA cage. Is this a late model unit? I have three manuals and none have this switch. Was there a manual that included this change? Thanks. gary Gary H. Harmon, Jr. - K5JWK 6003 Archwood San Antonio, TX 78239-1504 210.657.1549h / 210.884.6926c "Too many projects, not enough time".