[BC] FCC Info On Directional Arrays

[PeterH]

On Oct 15, 2009, at 5:18 PM, Tom Spencer wrote:

> The "standard pattern", which is derived from the theoretical array...
> IIRC, it takes the M3 ground data into account and normalizes the  
> field
> to a standard - I believe 1 kw - strength.

The standard pattern computation adds a "quadrature term" to the  
theoretical pattern computation, thereby imposing a minimum field  
within each null, but it does more than that as the maxima are  
affected as well.

The standard "Q Factor" is ( ( power in kW ) ^ 1/2 ) * 10 .

For a 5 kW pattern, 22.36 mV/m at 1 km would be added as the  
quadrature term. For a 50 kW pattern, 70.71 mV/m at 1 km would be  
added as the quadrature term.

In some cases a non-standard Q Factor is allowed, usually one which  
is lower than standard, but Q Factors which are higher than standard  
are also known.

You can obtain a station's Q Factor from the FCC's pattern data, the  
"Pattern Data for ..." option in the CDBS.