[HCDX]: Re: [AmFmTvDx] Re: New Expanded AM Band Station

[Allan and John Dunn <dunn@xxxxxxxxxxxx>]

Pres Waterman wrote:
> 
>  The bigeest problem in tuning things
> >      up was restoring the 1330 pattern after the diplexing filters were
> >      installed.
> 
> does anyone know exactly how this pattern tuning is accomplished and
> verified?

I am 30 years behind in my technology, but the basics should be the
same.  A MW directional antenna array has multiple towers that have the
feed to each of them shifted in phase to get the desired pattern.  This
can be done by tweaking variable inductors or capacitors in-line with
each tower feed with a device known as a phasor.

In the old days, a field strength meter (which is a calibrated receiver)
would have to be taken to known points several miles out to measure the
field intensity on the given radial(s).

The tweaking is more art than science.

-Allan-
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