[Elecraft] KX3 vehicle mount

[Josh Fiden]

Hi Jim,

It's not just hybrid & electric vehicles. Some newer conventional cars 
shut the engine off during idle to save fuel. There's a sensor inline 
with the battery neg terminal to measure charge & discharge rates to 
prevent the start-stop algorithm from causing a dead battery. If you 
connect direct to the battery, you will confuse the sensor.

73,
Josh W6XU

On 9/12/2016 2:52 PM, Jim Brown wrote:
> Not necessarily. There is no good reason to bond the radio to the 
> vehicle. It is, however, necessary to have good RF connection at the 
> antenna between the coax shield and the body so that it can act as a 
> counterpoise. That connection could be through a good RF capacitor. In 
> this were done, I see no reason why powering the radio directly from 
> the battery would be problematic, or would interfere with that system.
>
> Also, it seems to me that the system you describe is only viable with 
> electric or hybrid vehicles. There are other significantly greater 
> issues with installation of a HF radio in these vehicles.
>
> 73, Jim K9YC
>
> On Mon,9/12/2016 1:57 PM, Gmail wrote:
>> Newer cars that have the auto stop feature ( engine turns off at stop 
>> lights) have a sensor between battery negative and car frame.  In 
>> these cars the radio has to be connected to frame ground not the 
>> battery negative post or the sensor will not work right correctly.
>