Topband: K3NA Loop Array

[Eric Scace K3NA]

on 2010 Jun 21 10:38 Richard (Rick) Karlquist said the following:
>
>
> Eric Scace K3NA wrote:
>
>> R1: zero -- this resistor was only needed on 80m.
>>
>
> I'm still confused.  The loop has an unloaded Q of
> about 100.  Somehow, this is "matched" to Zo with
> a 10% bandwidth.  Where is the lossy element if
> not R1.  Could it be core loss in the MPP core?
    In the mathematical model of the matching network R1 was needed.  In 
the as-build prototype, it was not.  I suspect the core loss in the MPP 
core did the trick.

    On 80m I did need some R.
>
>
> Why connect the secondary winding of the transformer
> to the primary center tap?  Better to just connect
> it to the coax shield only and then you don't need
> the feedline chokes.  This is what I have been doing
> and it seems to work fine.

    Isn't is all the same?  The coax shield is connected to both the 
center tap of the antenna side of the tranformer and the bottom of the 
secondary.

    I used coax shield chokes widely just to be sure the shield is 
stone-cold.

-- Eric K3NA