question about TV antenna polarization

[ve3fnd]

Me and some of my ham buddys where talking about antennas and form my under standing TV stations broadcast with a vertical antenna polarization much like FM radio stations do. None of us knew for shure but if im right and they are vertical polarized why are all the TV antennas horizontal. And If im right on that i gess every one should flip there antennas 90 degrees and they will gain about 20db i cant see that being the case or they would sell vertical TV beams and verts insted of horizontally polarized beams. thanks for your help

JOHN VE3FND

 

[KR4BD]

In the United States, TV stations transmit horizontally. Look at the TV antennas on people's homes. They are horizontal.

ALL FM stations used to transmit Horizontally as well, but by the 1960's, it became obvious that horizontal polarization was not working well with mobile (in car) reception. As a result many FM stations now transmit BOTH Horizontally and Vertically.

 

[prcguy]

Many TV transmit antennas are a large vertical affair but radiate horizontal polarization. The vertical pipe is a circular wave guide and slots are cut at strategic points to form a collinear array of slots to produce a pattern towards the horizon with gain.
Many FM brodcast stations use circular polarization, which a vertical or horizontal receiving antenna will see with equal results.
prcguy

 

[kb2vxa]

Guys, you're ALL wrong. Both TV and FM started out horizontally polarized because it gives greater range than vertical. With the advent of FM car radios the FM stations added a vertical component with a vertical secondary bay and power divider. Maybe you haven't noticed that no matter which way the monopole whip on your FM portable or the set top rabbit ears are oriented you get worthwhile reception. That's because these days both FM and TV are circularly polarized. Don't look at the receiving antenna when the transmitting antenna tells the tale, check out the broadcast equipment catalogs.