Topband: vertical balun

[Dr. Wolf Ostwald]

Hello Bob !
a balun is absolutely the wrong thing to use. It supposes that both 
sides on the balanced side have the same impedance to ground. That 
definitely is not the case with a vertical and a ground system. The 
impedance you want to match is a composed one, simplified its the 
radiation resistance of the vertical and the ground loss resistance 
together. By using a balun output which equals the impdance of Your 
shortened vertical, You CANNOT eliminate the loss in the ground 
resistance. Further i doubt the measurments on the primary side of the 
balun. It is very likely done with a mter that does not have good 
discrimination or the loss in the core makes it look good. None of the 
AM stations ever used a balun on the output side with vertical 
antennas.And that for a reason . See " radio antenna engineering" by 
Laport . This is the download site , its free :

http://snulbug.mtview.ca.us/books/RadioAntennaEngineering/

after going thru this, all ur questions will be answered

wolf   df2py