[Antennas] balanced ant tuner question

[fkamp at comcast.net]

RB wrote:
> I'd like to go to Rich Measures Double Balanced tuner for
> my ladderline fed dipole.
> 
> However, I'm not sure how to know what is going on with
> it, as the circuit doesn't have an SWR meter (can't
> really, as the circuit inside the box is balanced).
> 
> Maybe dual RF ammeters on the output and tune for max
> out?
> 
> Or, an SWR meter between the rig and tuner.
> 
> What's the best way to go here? 

Probably both.  RF ampmeters in each leg to keep the roller 
coils balanced and an SWR meter in the coax to the tuner to 
monitor SWR. Or a very well designed mechanical coupling 
between the roller coils to one panel adjustment.

There are simpler balanced tuner designs.  The matchbox 
tuners made by Johnson have a balanced output, also without 
need for external balun.  Here they use variable capacitors 
connected to a common shaft.

Or just use the Z-match design.  It is not double balanced 
but it does provide output to open wire line without having 
to go through a balun.

I am not sure what advantage a DOUBLE balanced setup offers. 
Seems like it is overkill with a high degree of difficulty 
in use and construction.

Regards,
Frank Kamp
K5DKZ