Greetings Mr. Enno:
So, what is your answer?
My guess is that the coax cable cannot be used as an antenna, although I have had a number of times when my cables were so trashy that they leaked enough to radiate rather well. With a well-constructed coaxial cable, the fields are all contained within the cable cross-section and should not radiate at all.
BTW, I deleted the duplicate original post since it appears to have been a mistake.
- Kirt Blattenberger