--- On Thu, 2/16/12, Roger Rogerkola@aol.com wrote:
CB uses vertical beams...the difficulty is that they have to have a non metallic mounting pole extending into the beam or be end mounted (think torque)
The mounting pole may contribute some capacitive or inductive loading effects on the elements adjacent to it, but a smart antenna designer can modify the antenna's element lengths to compensate for these effects.
The pole itself will have a negligible effect on antenna performance, unless it happens to be resonant (or very close to resonant) at the operating frequency. Otherwise, it's essentially transparent.
On 2/16/2012 12:18 AM, Bob Bruninga wrote:
Just wondering if anyone has a vertical beam.
If the signal is strong enough (and/or the receiver sensitive enough), an electrically small loop antenna can be used for 28 MHz radio direction finding purposes.
A vertically oriented loop will respond to vertically polarized RF. (In reality, it's responding to the horizontally polarized H-field).
The ARRL Handbooks and Antenna Books have carried designs regarding 28 MHz RDF antenna for many decades.
73, de John, KD2BD