[TowerTalk] Pattern Distortion caused by faulty balun?

[Jim Brown]

On 1/2/2012 2:35 AM, Steve Hunt wrote:
> It only requires the realisation that the outer surface of the coax
> braid can - and does - act as an "unintentional" antenna wire to see the
> wisdom of using a choke.

I like the way you phrase your response with those questions. I also 
emphasize those concepts, but using different words.

  But it's also critical to convey the concept that a parallel wire line 
can carry considerable common mode current, thus doing exactly the same 
thing, if the antenna is unbalanced. The words "balanced line" are 
misleading, because current on the line won't be balanced if connected 
to an unbalanced antenna or unbalanced rig. That's why I am careful to 
talk about parallel wire lines, not balanced lines, and it's why common 
mode chokes are just as necessary with parallel wire lines as with 
coax.  The only difference is that with coax, the need is more obvious 
and easier to explain.

73, Jim K9YC.