It is both. If one desires to be precise then one should say television set. TV means both a device and a transmission system. In the USA one asks: "what is on TV tonight" (that means what is being broadcast or transmitted). Likewise one might say: "the TV is broken. Let's take it into the shop." I can go on and on if you like. It would just be a lot easier for the translators here to add the word "television" in for acceptable answers. I am not going to be the only person who is going to make these observations.