LF ERP w/ 1500W & 200W

[Paul L. Rinaldo]

Dear Andre,

You probably knew this all along.

73, Paul, W4RI
 
>BARGHAUSEN EQUATION
> 
>The Barghausen Equation expresses the dB gain to be expected from a short
>(less than 1/4 wave) vertical antenna.  I have located the equation but
>not the Barghausen reference paper.  As I recall, the equation resulted
>from curve fitting a few data points obtained from measurements of the
>radiation from a jeep radio operating over lossy ground with various size
>whips on HF frequencies below about 6 MHz.  There are probably better
>algorithms for this application!  This is submitted as a rough
>approximation of TPO verses ERP.  The equation is:
> 
>dB= -6416.702R^4 +6091.33R^3 -2179.89R^2 +364.817R -25.646
> 
>where:
>        R = (Length of radiator) / (Length of one wavelength)
>        R^x denotes raising R to the power of x.
> 
>Solutions of the Barghausen equation at 180 kHz with various antenna
>lengths (feet) and transmitter power outputs of 1500 and 200 Watts
>predicts the listed ERP in Watts.
>                                 TPO          TPO
>Antenna   Wave-        dB Ant    1500 W       200 W
>length    length       gain      ERP-W        ERP-W
>50        .01          -22       9            1
>100       .02          -20       19           2
>200       .04          -15       50           7
>400       .07          -11       230          30
>600       .10          -5        520          70
>800       .15          -3        810          110
>1000      .19          -2        1000         140
>
>73, Dick Wilder, K3DI