"Desmoface"  wrote in message 
... 
 How about a J-Pole? Low angle radiation. The bottom end can be connected 
to 
 earth ground. In fact, I constructed one using a mast with the 1/4 wave 
 parallel section added 1/2 wave below the top. Real easy. No radials. 
  
 
 thats also an option..i wonder if'n I'll need radials with a vertical 
dipole?? 
 
 Steve 
 kb8viv 
 
 
As others have replied, no you don't. 
 
I once made a 1/4 wave vertical and was listening to a local conversation on 
my IC-2AT when there occured a lightning stroke from a thunderstorm a few 
miles away. Although the mast and radials were grounded, the conversation 
disappeared for about 5 seconds and then faded back in. Electrical charge on 
the ungrounded vertical element. But I have never had this problem with a 
J-Pole since all parts of it can be at earth ground. I've also used folded 
vertical monopoles with the same results. 
 
In my old age I have probably become paranoid about ungrounded driven 
antenna elements. I know that some (maybe all) commercial antennas are 
designed with networks or other devices which does the grounding. If I were 
to build a simple ground plane today, I would make it a bit shorter than 
resonant and add a shunt inductor across the feed point. That way there can 
be no static accumulation on the element. 
 
By the way, we sometimes get sand/dust storms here. I have seen and heard 
the repeated discharges from the center pin to the shell of a PL-259 on a 
RG-8 line coming down from the roof during a sand storm. 
 
Anyway, this is not to convince anyone that a J-Pole is a cure-all or even 
the best choice. I just wanted to tell about what drives my choices and tell 
about a couple of my experiences. Anything you choose will be just fine, as 
long as you are aware of its properties. 
 
Have fun. 
 
John - KD5YI 
 
 
		 
		
		
		
		
		
		
		
		
	
	 |