Cb base station beam antenna

[Rjs66]

What's the lowest height I can put up a small beam antenna

 

[jwhutch]

its been a while so someone else should verify but I believe its 1/2 wavelength so about 16'

 

[DaveInDenver]

The rule of thumb @jwhutch mentions of λ/2 above ground is where the antenna will start favoring horizontal more than vertical. You can go lower it just reflects energy up more than out, e.g. is a cloud warmer, and higher will be better.