A TV antenna with its stick appearance is in reality a complete tuned circuit just like a combination of coils, resistors and condensers. The right TV antenna is tuned to the TV frequencies.
The tuning is performed by cutting the metallic sticks to match a particular half wave length. Channel two’s wave length is 200.2 inches while channel thirteen’s is 54 inches with the in between channels being in between.
The line or driven element (the one that is attached to the lead in wire) is thus cut at half wave lengths.
Practically speaking, in a good signal area the actual length is not really critical. So antennas are cut on or around the channel three length requirement. (The lower channel is picked because smaller wave lengths can be absorbed easily by a larger length, while larger wave lengths cannot be absorbed as easily by the smaller piece of metal.)