For Those Who Care...
It looks like it has to do with splitting the signal in my mixing board.
My mixer is a SoundTech KJ2000v is the same mixer as the VocoPro KJM-8000 Pro with a different paint job.
These mixers have video switching capability.
All video connectors are rca/composite
1 video input for each audio device/channel (a total of 3 inputs)
You need to manually flip the switch to the device your presently using.
Then there are 2 video outputs.
I put one to the RF converter (then to TV's thoughout the room) and one to a 13" TV (rca input).
With this configuration I'll get Blk and Wht after the RF connverter.
If I go straight from the computers video card to the RF converter i'll get color after the RF converter.
There must be some signal degradation by splitting the composite video signal in the mixing board.
Anybody know how to check that? (easily)
see my system:
http://www.newdjsolutions.com/rackmount_lcd.htm