Thanks for your help Andy,
My source is
Video: QTime.
Codec: DVCPRO50.
Standard: NTSC.
Resolution: 720×480.
Frame rate: 29.97fps
Aspect: NTSC / CCIR 601.
I managed to export all of the settings except the Data Rate? If I modify the Data Rate, I have to modify the codec DVCPRO 50 or the 4 Audio Channels.
How do I export with 7.5MB/s without modifying DVCPRO50?