L.A.R.S. FoxHunt Antenna Design
by Dr. Peter Rock KJ4ND
Sunday, September 10, 2000





 
	These diagrams show an antenna that should be easier to construct, and 
requires less material, and does not require any balun.  The diagram at the 
left shows one view of the antenna . It is basically the same as the one that 
I demonstrated at the last club meeting, except that it is a little longer, and 
does not require the other coax fittings,  except the one that connects to the 
HT (radio) . 
  	 Each wire element is 17.5 inches, and the center connector of the coax 
connectors to the similar side wire element . The coax in the center is split 
off-center , with 18.5 inches on one side , and 11 inches on the other side . 
The coax center connectors all connect together; and the shields all connect
together ( at the feed point ).     This will give the antenna a deep null on one 
side, which should be better than the one given in the copy of the radio 
book I gave you .



NEW IMPROVED ANTENNA DESIGN







	This new antenna design is the one I currently use, and is more 
useful than the previous one I had listed on this site. The upper diagram 
shows that this 2 meter fox hunting antenna is made with two half wave 
antennas spaced about .25 wavelenths apart. In this case they are 18 
inches apart. The length of each half wave is 17.5 inches, and they are 
fed at their centers. The antenna wire making up the antenna can be 
supported on wood, pvc pipe ( either inside or outside) or any other 
insulating material. 
	This antenna is simpler to make , because it only requires one 
piece of coax (other than the coax from the HT ). Refering to the lower 
diagram, the coax between the two half waves is 18.5 inches, slightly 
longer than the spacing between the half waves. This is to provide the 
proper phasing between the half waves. 
	Note that the connections to the center connectors (blue) are 
all on the same side (i.e. upper) , and that the connections to the shield 
(yellow) are on the same side (lower). That is very important for the 
correct phasing also. 
	In this antenna the coax from the HT connects to one side of 
the fox antenna. The pattern this gives is seen on another diagram , and 
has one large lobe in the front, and a smaller lobe in the back, making it 
easy to tell which is the peak direction, and two deep nulls off the sides 
approximately broadside. 
	The exact location of the nulls may vary a little, and the exact 
location can be found after constructing it and testing it on a radio signal 
of known location. 
	I believe that you will find this to be a very useful fox hunting 
antenna. 
			73's 
			Peter KJ4ND