mobile antenna impedance comparison
			 
			 
			
		
		
		
			
			QST 
It's been a while since I posted all that bazooka data that made me stick to 
dipoles, so here goes: 
I've been using Hustlers mobile for almost 40 years and find them adequate; 
The mast I bought in 1970 only recently failed. 
I'm reworking my HF mobile installation around a TS-480HX and decided to 
graduate to a screwdriver. I bought a Tarheel 200. 
I prefer to operate a mobile antenna at it's resonant frequency and match to 
the impedance of the transmission line with a transformer. 
So here I present the resonant feedpoint impedances of a Hustler (small 
resonators), the Tarheel 200 screwdriver and a 103" whip on a bug catcher on 
a 54" Hustler base. All antennas on the same ball mount. Measurements by 
MFJ. "Resonant" implies X=0. 
 
band     Hustler     Screwdriver   103"/BugCatcher/54" 
80        21 ohms     9 ohms              23 ohms 
40        25             11                      na 
20        30             30 
10        40             32 
 
I really thought the huge bug catcher would do better. 
The screwdriver shows encouraging results for signal improvement over the 
others on 80 and 40. 
Seems the diameter of that bottom conductor on the screwdriver makes a big 
difference at the lower frequencies. 
Since the TS-480HX has two antenna jacks, I think an additional small 
screwdriver is in order; One for 80-20; One for 20-6. 
73 
H. 
NQ5H 
 
 
		 
		
		
		
		
		
		
		
		
	
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