Tape measure antenna with hairpin match
			 
			 
			
		
		
		
			
			A few days ago I constructed  a tape measure type antenna for 2 meters. 
It is a 3 element beam and uses a hairpin or beta match. 
 
Ran a return loss on it with the signal generator/spectrum analizer.  The  
best return loss was about 149 Mhz instead of 146.  Thought it may be  
because the tape AI used was 1/2 inch wide instead of 1 inch wide.  I tried  
lenghtning the hair pin form 5 inches to 6 inches.  This did not change the  
frequency of the return loss to any great ammount , but the RL went from  
around 20 or more db to 10 db. 
 
Did a little research on the hair pin match.  From what I am getting out of  
this, and it is very rough, is that the length of the driven element does  
not make much differance in the actual resonate frequency of the antenna.  
It is mostly where it is placed on the boom and the other elements that  
determin the frequency of the antenna, but the length of the driven element  
is determined by the impedance of the transmission line to be matched and  
the impedance of the antenna/driven element. 
 
Is that mostly correct or did I miss something in my reading ? 
 
 
		 
		
		
		
		
		
		
		
		
	
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