Roy Lewallen wrote:


Have you read the article at
http://eznec.com/Amateur/Articles/Baluns.pdf? If you have but still
think that, then I certainly failed to communicate.

For the benefit of readers who have read the article, I didn't mention a
second source of imbalance: mutual coupling to the antenna. This can
occur if the feedline isn't run completely symmetrically relative to the
antenna. And, interestingly, there are situations where this is
occurring that inserting a balun can actually increase the common mode
current. That's a story for another article some day. But first I've got
to somehow get people to read the first one.

Roy Lewallen, W7EL

Hi Roy,

Yes, I have a copy of your article, and I have actually read it. I think
I even understand it. I took a fresh look just before I made my first
post in this thread. The schematic for Sevick's Guanella 4:1 balun is
exactly the same as your figure A3-4.

The only question I have is regarding the issue of two cores vs. one
core. I have no doubt that grounding one of the high impedance leads can
lead to improper choking action with a single core. In the completely
balanced case the single core should work perfectly. So what happens in
a more typical case where the antenna is in an unbalanced environment,
but not fully shorted to ground on one side?

There are a number of designs out there for single core 4:1 "current
baluns", all essentially the same, including the Elecraft balun. I have
not tried to perform any measurements, so I have no idea whether these
designs typically work or typically fail. That was the foundation of my
original comment and question.

73,
Gene
W4SZ