digivox xl on ntsc lcd tv?

hi mike here can anyone help
iv aquired a north american lcd tv and have it linked to my digivox via scart to composite (RCA) but the picture is not so good ,ive tried setting the output from the box to ntsc on moderator but makes it worse,
if i change to rgb output it makes no difference, i havent tried changing to rgb and plugging rca leads into rgb ports as i was affraid it could cause damage to digivox
any suggestions would be gratefully apprecieted
thanks mike