Hi, Jim.
That's not what I meant, and I think you probably know that. But yes, I
should have been more precise like I often preach. ;)
What I meant was in the context of my comparison to elements for
different bands on a tribander. Certainly grounded vertical elements
have resonance different than if they weren't grounded, but the coupling
between a grounded tower adjacent to a vertical fed against ground isn't
conceptually any different than than the coupling between adjacent
elements that are not grounded. Lots of hams think there is something
mystical about "RF ground", and I was just trying to head that off.
73,
Dave AB7E
On 1/16/2019 12:17 PM, Jim Brown wrote:
On 1/16/2019 11:04 AM, David Gilbert wrote:
The fact that the tower is grounded is irrelevant.
That's not true. It matters a lot. Compare a 125 ft tower that is
insulated at the base with one that is grounded at the base. On 160M,
the grounded tower is near resonance, but nearly an open circuit on
80M. And the tower insulated at the base is nearly an open circuit on
both bands!
73, Jim K9YC
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