[Lowfer] FWD: Antenna design idea question

[JD]

>>>  I will only use the upper area of the vertical for the helical windings 
>>> and go with no capacitor hat first but will add it if needed later. >>>

Trust me, you'll save a lot of time if you go ahead and figure on the top 
hat from the beginning.

The rationale that "you don't want to use a capacitor hat because as the 
antenna has more capacitive toploading the importance (and thus the gain) of 
the distributed inductance decreases" is flawed.  As others have said, this 
type of antenna does not scale well to LF.  There are very practical reasons 
why distributed inductance is not that meaningful down at these frequencies.

You need to maximize current flow all the way to the top of the vertical 
run--pure and simple.  Distributed inductance along a vertical radiator only 
15 meters in length just doesn't do it!  A capacitance hat is more 
beneficial by far--which is something other experimenters have found over 
past decades.

John