Topband: Beverage question

[Tom W8JI]

> So, how to measure the bev? Is this procedure correct:
> The bev is ~8 feet above ground. The far end is open, not grounded, no 
> resistor.
> The analyzer connects directly to the bev and the ground rod at the rx end 
> through its bnc-to-banana plug adaptor . Measure and note the impedances 
> for 160, 80, (40, 30m). Calculate the mean average.
> Calculate and install a transformer to match that value to the feedline. 
> At the far end, find the value for the termination resulting in a flat 
> swr-curve over the range 1.5Mhz - 10Mhz.
> Correct?

There are two ways to do this:

1.) measure the impedance peaks and the impedance minimums and take the 
geometric mean of the adjacent peaks and minimums and average them. This is 
almost certainly the least accurate method.

2.) measure the SWR variation with frequency as you adjust termination 
resistance. The resistance that gives the minimal variation with frequency 
(using a continuous sweep, not band by band) will be the proper termination.

In all cases, be sure you have reasonably good grounds. Several spaced rods 
or a few short buried radials and some rods will generally work, ground 
resistance only has to be less than 50 ohms or so.