[Mobile-Portable] Mobile Antennas ground loss

[MELVYN EVANS]

--- K7fe at aol.com wrote: > Dave,
> Have you ever looked at the relationship between
> "ground loss" and overall  
> antenna length at 40 meters (neglecting loading coil
> and conductor  losses)?  
> As you know, the antenna variables of proximity to
> ground  producing ground 
> loss and the overall length of the radiating element
> and  resulting efficency 
> combine to become the system efficency.   Given 
> that the maximum vehicle height 
> is 13 ft 6 in, if you mount an antenna  about one
> foot above the ground below 
> the bumper, then the maximum antenna  length would
> be 12 ft 6 in.  One could 
> also mount the antenna on the roof  of the vehicle
> which would lower ground 
> loss while shortening the antenna  length to about 8
> ft to stay within the max 
> vehicle height limit, resulting  in reduced radiator
> efficency because more coil 
> would be  required.  
>  
> Is there a program to model this and have you any
> thoughts as to which  
> mounting location produces the best overall results?
> 
>  
> 73, 
> Terry, K7FE
> ----
> Your Moderator: Dick Flanagan K7VC,
> mobile-portable-owner at mailman.qth.net
>  
Hello Terry,

The losses involved with a mobile vertical antenna are
so large that raising an antenna by a couple of feet
or so would not make much of a difference to the
person
at the receiving end

73,  Mel