[TowerTalk] TH6DXX Adjustments

[K7LXC@aol.com]

In a message dated 98-12-30 11:12:30 EST, n7cl@mmsi.com writes:

> Not only is it easier said than done, it isn't a good idea
>  either.  You have absolutely no mechanism (other than pattern
>  measurements) to determine the correct settings for any of the
>  parasitic elements.  Unless you have some reason to suspect that
>  one is simply not working due to a fault of some sort, you should
>  not fool with it.  Changing parasitic element dimensions to
>  modify the feed point impedance is virtually guaranteed to
>  produce an array that is not set up correctly to produce the
>  desired directivity.
>  
      Howard Pabian, a Hy-Gain antenna design engineer, spent six months
designing the TH6 doing dozens and dozens of iterations. A one inch change in
dimensions took four hours to test and plot. And he had a professional antenna
range at his disposal.

      Unless you are a qualified antenna engineer and have a professional
antenna range at your disposal, all you can do is screw it up by changing it. 

      BTW one of my Up The Tower columns in the NCJ covered Howie and the
(then) 30th anniversary of the introduction of the TH6 - arguably the most
popular (along with the same design TH7) high performance tribander ever
produced. 

Cheers,   Steve   K7LXC

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