Roy Lewallen wrote:
Mike Coslo wrote:

. . .
I don't doubt that someone might come to a different conclusion,
but I think my reasoning is pretty sound. I modeled an equal length
version of this in 4nec, and it just doesn't work very well. OTOH,
turn it into an OCF dipole, and it is a different story. . .


How did you possibly determine what the balun input impedance was when
terminated with the impedances the antenna presented on the various
bands?

You are correct, I couldn't. But what I got was enough to tell me that
with the two sides of equal length, there wasn't much need to go any
further. Cannot some antenna characteristics be modeled without the
entire system in place? I'm no expert, so I'll ask the question: Is
there some Balun that will make a 135 foot equal length antenna perform
on 80-10 meters?


How did you model the balun? It's almost certainly a "voltage"
balun which will force common mode current onto the feedline when
terminated with an asymmetrical load. Because of the common mode
current, the outside of the feedline must be part of the model. Did you
model the antenna with various lengths and orientations of feedlines?

I don't believe that a valid model can be made of this type of antenna
without knowing and accounting for the major imperfections of the balun,
the common mode current it forces, and the feedline length and
orientation for the particular installation.

It isn't whether my model is exceptionally valid. I don't know what the
balun is that they use, so that sense it doesn't matter anyhow. You
would know much better the balun that would make this antenna work.

I'm just looking at what is there, and by looking at both the context of
the advertisement, references given for their other antennas and the
like, I'm just saying that I suspect that that antenna is a OCF dipole.

Their G5RV antennas do *not* have an L1 and L2 to designate length of
the sides. If that antenna has an equal length side, it is the only one
on the site that does. Yeah, I know they are not really G5RV's.

In addition, is BuxCom going to try to sell a product that apparently
doesn't work? I don't see any of the hype that tends to go along with
the "magic" antennas we sometimes hear about

All of the above just about convince me that the antenna in question is
an OCF dipole, and that the description and image is a big typo.

Others may take it at all at face value, disregard all the evidence to
the contrary, and assume that the sellers are just trying to hoodwink a
gullible public into buying a non-working product.

That doesn't make sense to me. YMMV

- 73 de Mike KB3EIA -