Roy Lewallen wrote in
:

Owen Duffy wrote:
Roy Lewallen wrote in news:13la97elqjdp5e2
@corp.supernews.com:

Owen Duffy wrote:
. . .
The helical problem I posed is not unusual, many if not most low HF
helicals wind up with close spaced turns at the top. . .
Out of curiosity, why?

Why are they made that way, or why my interest?

Why are they made that way?

I suspect that it is a technique to try to maximise the current moment to
get the highest radiation resistance. They then build out the radation
resistance with loss to achieve a specification maximum VSWR for direct
feeding at the base with 50 ohm line.

Owen