[Amps] Testing a tuner

[Tomm Aldridge]

My balanced tuner is configured with the motorized roller inductors 
(26uH ea) in series mechanically with about a 2" separation.  I have the 
capacitor split between 2 500pF Henry variables, one of which is almost 
always shunting the output of the 24 turn x 4" coax balun on the input 
of the tuner.  This coupling has not caused me any grief to date.  If 
you were to make a link coupler I would suggest opposed drives so the 
tank L increased or decreased symmetrically around the center where the 
link was located.  The second motor would be simple enough to add.

Tomm, KD7QAE

Rob & Terri Sherwood wrote:

> If the League is really only using resistive loads, then they could make 
> the loads reactive with inductors or capacitors.  This would be time 
> consuming, but what other option do they have?   The balanced L network 
> tuners I have tried matched fine into resistors on 20 meters and above, 
> but hooking them to a real antenna was another story.
> On the balanced L network tuners, putting a 10 - 100 pF variable 
> capacitor on the input solved virtually all my matching limitations. 
> What does this imply?   In every case the output Z was higher than 50 
> ohms because swapping the L network capacitor to the input always made 
> the matching worse.  So why did converting it to a Pi from an L make 
> such an improvement?  The balun was always on the transmitter side.
> I am wondering if one could build a modern Matchbox with the following:
> Two roller inductors in line mechanically and driven by a turns counter, 
> and the link located in the middle between the two roller inductors.
> Then of course we need a split stator and a dual differential capacitor.
> 
> Someone mentioned the issue of coupling between the balanced L network 
> coils.  If there is too much mutual coupling between the coils, what 
> will happen?
> 
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