Topband: BOG Beverage on Ground Help

[Mikek]

Hi guys,
  I see certain measurements for the length of a BOG, such as 200ft for 
for 160 meters.
  And even a warning on one page,
/*
"The biggest mistake is making the BOG antenna too long. Try not to go */
/*over 200 feet for 160 meters."

*/So, if I tried to use this 200ft BOG on 80 Meters, I assume it has 
receive problems.
A short explanation of those problems would be helpful, Impedance? Pattern?
   I've been pondering over W8JI's Loaded beverage page.
> https://www.w8ji.com/slinky_and_loaded_beverages.htm
I'd like to apply the loading to a BOG to slow the VF and make it seems 
longer.
  ie. make a 80 meter BOG length work on 160 Meters. But then make the 
reactance go away for 80 Meters
  My actual goal is to have a BOG that covers 500kHz to 4MHz.
To that end, I have been working on a variable inductor that I can 
insert into the length of the BOG.
In reality, it would be eight Variable inductors spaced about 35 to 40ft 
apart. I'm land limited to about 270ft.
  I want to control the inductors with a DC current through the BOG wire.
  I have a 100uh toroid inductor that I can partially saturate with an 
electromagnet.
  The electromagnet is energized by an adjustable current through the 
BOG wire. This means I need
to RF bypass the Electromagnet, so it's inductance is not seen by the 
RF. Also I must block the RF
from seeing the Power supply/current source.
  I have a drawing showing my proposed circuit here.
> https://www.dropbox.com/s/wrfpubqvsfd11nq/bog%20with%20variable%20inductors..jpg?dl=0
  I want to be told what problems you see and ways to overcome them. _If 
it is at all feasible_,
I would wonder about the values of the blocking caps and Chokes.
  I appreciate any thought you can give this idea.
                                                  Mikek