Topband: An oddball question about a BOG.

Mikek amdx at knology.net
Sat Aug 24 13:38:40 EDT 2019


>  The trick is to take the dc control winding and it's inductance out 
> of the antenna circuit, which I think can be done with a large bypass 
> capacitor.
> Here's a simple drawing.

> The BOG goes to antenna in, through the .47uF cap (Xc=.67ohms at 
> 500kHz, 0.1 ohm at 4Mhz) through variable inductor, (the toroid)
> (0uH to 100uH) and the antenna out to the BOG, 30ft later is another 
> one, nine required.

> https://www.dropbox.com/s/f6w7zk74azjtvdc/saturable%20core%20inductor%20db.jpg?dl=0

 >I suspected you had this idea in mind.  Unfortunately, a second wire 
will kill the gain and pattern.
Beverages don't work over wire fences (I proved this at my ranch) or 
salt water or other conductive surfaces. So you need to find a design 
(inductor) that the antenna wire can  also be the current source.

I'm confused by the answer.
  My idea was working at eliminating a control wire to each inductor 
wire, That's why I run the current through the antenna wire.
Ahh, but, I do have a second wire, it is at the end of the bog.  Is that 
the pattern killer?
  Can I optoisolate the DC control so the wire is isolated?
  I had a variable resistor at the end of my previous BOG and it did not 
kill the pattern. That required a second wire at the end of the BOG.
But it used a Vactrol that isolated the antenna from the control.

                                                  Mikek




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