[BC] lpfm question

[Richard Fry]

RichardBJohnson wrote:
>It has always been that a broad lobe that floods the intended receiving
>area will out perform some pancake pattern from a high-gain array that
>goes mostly over the heads of the intended receivers, the receivers then
>receiving mostly scatter, rather than a direct signal.
_____________

A high gain UHF TV transmit antenna can be specified to have whatever beam 
tilt is appropriate for the installation, and the useful coverage area. 
That is what TV consulting engineers do when they specify the patterns/gains 
for the station's antenna system.

For all practical purposes a high-gain, omni antenna with beam tilt can 
radiate close to the same ERP in the elevation sector serving its useful 
coverage area as if a low gain, or even an isotropic radiator was used. 
That radiation doesn't go over the heads of the receivers it is intended to 
serve, or need to serve them mostly with scatter.

The reason that this is true for UHF TV transmit antennas is because, as 
installed, they actually produce the az/el radiation patterns they are 
designed and documented to have.

Not so for the typical side-mount, non-panel FM transmit antenna array, even 
for moderate elevation gains.

RF