Automated "radio checks" can be conducted on VHF 27. It is sponsored by a "National towing company". Basically request a radio check on VHF 27, the receiver rebroadcasts your transmission back to you. So you will here it as it was received. The Freeport location has been operating for awhile. The Oakdale location should be up by mid week. This service should be available whereever there is a "yellow" franchise.