Topband: New Beverage

[Greg - ZL3IX]

I have recently erected a 320m Bev at my new remote receive site.  This 
is the first Bev I have used in ZL ( I did have one in ZS), and it is 
working extremely well.  Since I also have an N2PK VNA (vector network 
analyser) I decided to do an impedance sweep of the Bev at the feed point.

Before deciding on a value for the termination resistance, I measured 
the DC resistance to ground at the far end, and chose a value of 
resistor that would make the series combination up to 500 ohm.  The 
swept impedance is a bit irregular, but the peak to peak resistive 
component varies between 465 and 505 ohm, so I don't think the 
termination is far out.  What surprised me at first, was the fact that 
the reactive component is always capacitive (averaging about 1000 pF).  
I had expected it to swing between slightly inductive and slightly 
capacitive.

After further thought, I guess that the series capacitive reactance is 
due to imperfect grounding at the feed end.  I can imagine that my 
ground stakes don't make DC contact with as much soil as they do AC 
contact.  Do the guru's agree with this supposition?

If anyone is interested, I can e-mail the R+jX plot.

73, Greg, ZL3IX