Although many local broadcasters transmit their high definition content over DirecTV and Dish Network, there may be some channels available you can only get over-the-air. Additionally, terrestrial HD broadcasts received over an antenna remain the highest quality available, using far less compression to maintain a higher level of picture quality. Many modern satellite dishes and decoders no longer require the use of an external diplexer to combine the outputs of a rooftop antenna and the dish itself, accessible through your DirecTV or Dish Network satellite box. Tips Writer Bio
