[Elecraft] HF Rigs in Vehicles

[Jim Brown]

On Wed, 31 Mar 2010 18:33:40 +0100, David Cutter wrote:

>all 
>military vehicles, land sea and air, require a separate dc return other than 
>the chassis for the battery negative terminal.  Filter caps for emc are 
>returned to the chassis of the equipment which is strongly bonded to the 
>chassis of the vehicle and dc return is a separate wire to the battery 
>supply negative. 

That's nice. Unfortunately, vehicles sold to the public often do NOT have 
anything approaching bonded chassis. After buying a Toyota Sequoia several 
years ago during a Chicago winter, I took it into the heated loading dock at 
K9IKZ's business to scope out the installation of an HF rig. First thing we 
checked was body bonding. It wasn't pretty -- for all practical purposes, 
ALMOST NONE of the body parts showed anything approaching a low DC resistance 
between them. We found bolts inches apart with 30 ohms between them, and 
almost ten ohms between the battery negative terminal and the chassis!   

Tom -- it's really good to see you here. Your experience and engineering 
chops are greatly appreciated. 

73,

Jim K9YC