Topband: Topband Tower Antenna With Two meter Vertical

[Jim Brown]

On 4/15/2012 8:49 AM, Wayne Rogers wrote:
> Also - on the antenna installation.  Typically the two meter vertical's outer conductor will be grounded to the tower at the base of the two meter antenna.  I could also keep the two meter antenna insulted from the tower for its entire length up to the lightning protector just before it enters the house.  What's the recommended practice?  Ideas?

First, always run rotor cables and coax for antennas mounted to the 
tower INSIDE the tower. This allows skin effect to minimize 160M current 
on those cables.  Second, proper bonding of the coax shield to the tower 
top and bottom is good practice for lightning.  Third, coming away from 
the base of the tower, wind as many turns as you can of each cable 
through at least one #31 toroid.  This prevents these cables from 
becoming part of the radial system.

Ferrite beads clamped onto a cable are next to useless on the HF bands 
because they are inductive, not resistive, so all they do is TUNE the 
cable to which they are attached.

If the tower is very close to the house, it should be bonded to the 
combination of all grounds in the house, which, MUST be bonded 
together.  That includes power entry, telephone entrance, cable TV, 
satellite dish, ham shack, etc. If the tower is distant from the house, 
only the cables coming from the tower should be bonded, not the tower 
itself.

73, Jim Brown K9YC