Hi Johan. We have a Glomex TV antenna at the masthead. It was already fittted when we bought the boat, and although we hardly use it, we decided it would be silly to take it off, in case we become more TV dependent in future, when hopefully we will be spending more time on the boat.
We have however tried it out a couple of times, just to make sure it really did work, and justified the extra windage(!), and it has performed satisfactorily, both with a laptop with a TV dongle, and with a 12v Panasonic TV.
Hope that helps.