[TowerTalk] grnding coax braid at top of tower..is a balun even required ??

[Jim Brown]

On Fri, 4 Jun 2010 08:40:41 -0700, Jim Thomson wrote:

>Rauch advocates grnding the braid of the coax at the  top of the tower 
>and or mast asap.

This is partially for lightning protection, but it also has the advantage of 
minimizing noise pickup on the feedline. Tom's absolutely right. It is a VERY 
good idea. It's also great if you want to load the tower on 160 or 80. 

>Why not just make the coax an electrical odd multiple of a quarter wave..
>and then bond the braid to the tower. 

The best approach is to bond the braid AND use a good choke right at the 
feedpoint. Remember, we want to take the feedline completely out of the game, and 
the typical length of coax between the feedpoint and the tower can make a pretty 
good RX antenna.  

All of that screwing around with coax length is a PITA. The right choke at the 
feedpoint (see my Cookbook) always works and the feedline length doesn't matter. 

73, Jim Brown K9YC