Topband: Sloping Top Hat

[Telegrapher9 at aol.com]

Rune,

the 16.5 m vertical with three horizontal, 9 m top hat wires has a radiation 
resistance of 12 ohms. A base loading inductance of 15 uH will tune the 
antenna to 1.8 MHz. This antenna is resonant at 2.2 MHz with no inductor. 90 pF in 
series at the base will tune the antenna to 3.5 MHz and the feedpoint R is 80 
ohms. 

Sloping the top hat wires at 45 degrees gives a radiation resistance of 8 
ohms. A base loading inductance of 15 uH will tune the antenna to 1.8 MHz. This 
antenna is resonant at 2.3 MHz with no inductor. 100 pF in series at the base 
will tune the antenna to 3.5 MHz and the feedpoint R is 50 ohms. 

   Dave WX7G