[TowerTalk] RF Ground is a Myth

[Hans Hammarquist via TowerTalk]

Gentlemen,


Ithink we can conclude that any "grounding/bonding" systemis "only" for lightning protection and for our safety, andis not that good as an RF ground. RF grounding, when needed, shouldbe treated separate from the lightning protection.


Apoint here is what the lightning protection is for? 


We canencapsulate our radio shack, radio bunker, what-have-you withshielded walls. floor and ceiling, surge protections for power lines,antenna feeders etc to a point that the equipment is protected fromlightning strikes without any grounding what-so-ever. (I have triedto do that with my newly built shack.) Grounding the shack can evenbe counter-active as the current from a lightning strike in the towermay go through the equipment in the shack to the ground.


Ourgrounding rods, Ufer ground etc is to limit damages to thesurrounding, connected to our shack by power lines, telephone linesetc. The better grounding/bonding system we have, the less damageswill happen to equipment in the surrounding, not protected by our own elaborateprotection. It's the same reason the utilities are grounding/bondingtheir lines and equipment with extensive use of grounding rods.


Ihave nine rods connected to my tower, three per leg. I don't know ifthis is enough and I hope not ever to find out. I have a heavyconductor connected between my tower and the shield surrounding my shack,hope that a strike to my tower will not damage equipment in my shack. The shield is “only” grounded through the  tower and its groundconnection as I don't want current from a strike to go through the shield if I can avoid it.


Best 73 de,


Hans - N2JFS