Remove OMF from Archived Redo Logs

 Hi all

I have created the database with command line manually (without dbca). 
Oracle saves the ARCH Files in the FRA with an OMF Syntax. I don't like OMF...

How it's possible to remove them?

Oracle 11.1.0.7.0

Show Parameter
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db_create_file_dest                  string
db_create_online_log_dest_1          string
log_archive_format                   string      ARC%s_%r_%t.arc
log_archive_dest_10                  string      LOCATION=USE_DB_RECOVERY_FILE_DEST
db_recovery_file_dest                string      F:\choE\FRA
db_recovery_file_dest_size           big integer 1047483648

creates files like this
**************************
F:\choE\FRA\CHOE\ARCHIVELOG\2010_01_21 1 O1_MF_1_3_5OJTP2KX_.ARC

Thank's for your advice