Antennas are classified to 3 types based on the signal it gets. The 3 types are UHF, VHF and Unique combination signal. VHF signals are considered stronger than UHF. Another type of antennas called channel cut antenna is also available. It is designed to receive one transmission. This ideal for cable TV houses which want to get some local programs or functions to rebroadcast.  If a particular channel has a lot of transmitters and if it is difficult to receive signals in the normal way channel cut designed to receive that particular relay is the better choice to get good reception and clarity. After all TV antennas is product made by man and it should be able to make it function as we feel. TV antenna selection guide is a valuable reference to sort out difficulties in the functioning of TV antenna. The ability of TV antenna to receive signals at a specific frequency is called gain. It is always advisable to buy an antenna with good gain rating. The antenna with good gain rating will be normally longer in size and will have more cross pieces. Normally antennas are placed in the direction of the transmission location so as to get clear and effective signals.