Hi Tom,
>From: "Tom Rauch" <w8ji@contesting.com>
To: <towertalk@contesting.com>
>Date: Thu, 8 Apr 1999 22:17:53 -0400
>
Snip...
>> In fact, EZNEC does provide for accurately modeling reactive
>> complex network loads. In the "loads" entry widow, you must
>> specify "laplace" for the load type. This will delete all
>> current loads. Then you can enter the load parameters as
>> capacitance, inductance and resistance values (either in
>> parallel or series as appropriate). The main advantage of
>> this entry method is that the net reactance will be correctly
>> reevaluated for any change in the source frequency.
>
>That makes it easy. Roy Lewallen also suggested to change guy
>lengths, I try the rescale to a new frequency change. Say I
>want to shorten the lines 30%. I just type in a new frequency
>30% higher as a rescale. Then I type in the old frequency. No
>need to alter the wire tables.
>
>I'm not sure how that would work using laplace loads.
The load reactances will be evaluated at whatever frequency you
run the model. A frequency rescale will not rescale the load
network component values.
However, besides rescaling the wire lengths, a frequency scale
will also change the diameters. While this may have a small
effect on the model behaviour, I'd reset the wire diameter after
the rescale for best accuracy.
73, Eric N7CL
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|