[TowerTalk] Balun Recommendation

[Jim Brown]

On 4/21/2012 8:53 AM, Joe Giacobello, K2XX wrote:
> Finally, an explanation.  Thank you, Ian.

Finally?  It's been in my RFI tutorial since early 2007, and also in the 
Power Point on Coax Chokes first posted around that time, and both have 
been referenced here MANY times. .  .

I fully agree with what Ian has posted, which is in complete agreement 
with what I've been teaching for quite a while. The Coax Chokes Power 
Point pdf begins by observing that nearly all antennas are unbalanced by 
their surroundings, EVEN when fed by parallel wire lines.  And I have 
repeatedly emphasized use of the words "parallel wire" rather than 
"balanced line" to emphasize that reality.

On 4/21/2012 4:02 AM, Steve Hunt wrote:
> On my web site I explain how a predominantly reactive common-mode choke
> has the potential to increase CM current if the reactance of the CM path
> is of similar magnitude and opposite sign to the choke reactance.

See Page 7 of http://audiosystemsgroup.com/AESPaperFerritesASGWeb.pdf   
published in 2005, and a year or so after in the first edition of my RFI 
tutorial.

On 4/21/2012 8:12 AM, Ward Silver wrote:
> I'm really enjoying the multiple threads and discussions that started with baluns and have come around to an analysis of the entire antenna system.
>
> That changing just one element of the entire system in isolation is unrealistic is a key point that most hams do not appreciate - indeed, they rarely hear that point of view.  They learn about antennas as one independent thing, feed lines are another thing, baluns a third thing, and so forth.  Thus, they tend to analyze and troubleshoot and modify assuming changes "here" don't affect behavior "there".  Since changing almost any part of the system affects the entire system, the results are wildly inconsistent and often mystifying - as noted by Ian and others.

Again, complete agreement.

73, Jim K9YC