Review of excellent portable antenna

[Chuck Guenther]

I wrote a review of the N6BT Bravo 7K antenna for eHam about a year ago.
After using it for a year on all bands (40 thru 10 meters), I remain very
pleased with it.  Band changing can be accomplished in just a few minutes.
It seems to perform as well as my Force 12 Sigma 40XK, and is easier to
work with, and visually less obtrusive to the neighbors.

N0AX gave some excellent suggestions in his QST review, i.e., putting the
coil jumper wires outside the coil box, and using some light guying on the
antenna when using it on the portable tripod mount.

73,
Chuck  NI0C




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[w7aqk]

The Bravo 7K is, indeed, an interesting new design by Tom Schiller, N6BT.  I
initially "home brewed" a version of it, which wasn't that hard to do using
the information available online.  Subsequently, I was able to obtain the
actual antenna itself, and I have been doing a lot of comparisons with it.
What's really impressive about the antenna is that it is really something
that qualifies as being "portable", although it's not like an MP-1, or
similar, as far as portability goes.  Nevertheless, it breaks down quickly,
and into something that you could easily fit in a relatively small canvas or
nylon bag.  It's also lightweight, but reasonably durable.

I also have a Sigma 40XK (Force12), which is another Tom Schiller design
from when he owned that line.  Most of my comparison efforts so far have
been between that antenna and the Bravo 7K.  I will tell you that I have
been very happy with the Sigma's performance on 40 meters.  It's something
of a compromise antenna, but still it does a very good job, and better than
my R7 on that band.  The problem with the Sigma is that, although it is
advertised as being multiband capable, changing bands is no easy task.  So,
I tend to leave mine on 40 meters.  The Sigma 40XK could also be considered
to be portable, as it breaks down nicely as well, but not as quickly and
easily.

The Bravo 7K, on the other hand, is much easier to switch from one band to
another.  The matching section is easier to access, and is designed for
relatively quick band changing.  There is even a version of this antenna
that allows you to do all this remotely, but it's considerably more
expensive.

Unfortunately, my comparison testing on 40 meters, so far, has demonstrated
that the Bravo 7K is consistently about an "S" unit, or a bit more, below
the performance of my Sigma.  That's not terrible, but it was disappointing,
particularly due to my expectations based on the hype.  I do need to do more
tests, however, since I may not have the antenna located quite properly,
etc.  As Tom Schiller is quick to point out, if you've ever heard him make a
presentation, it's very easy to have nearby objects interfere with antenna
performance.  I think I am quoting him reasonably accurately when I say that
anything within a quarter wavelength distance or so can be a culprit.

I also read Ward Silver's review of this antenna, in the March 2012 issue of
QST, with great interest.  I believe Ward to be something of an antenna
"guru", so I tend to take his opinions seriously.  Sometimes, though, I
can't help but wonder if QST isn't a bit loathe to be overly critical of
some things they review.  It certainly seems that way at times.  In this
review, for example, Ward makes no attempt to confirm the designers claim as
to antenna efficiency.  I've seen other examples of antenna reviews by Ward
where he goes into considerably more detail about analyzing performance.
Nevertheless, Ward made a fairly strong statement in support of this
antenna's merits at the end of his review.  If he's right, I should be able
to get even better performance from mine with a little "adjusting".

The portability of this antenna is not insignificant.  For me, this antenna
could be an excellent solution to some of my varied operating needs for
travel, camping, etc.  For example, we spend a good part of our summers on
the Oregon coast, and I am anxious to take this thing right down on the
beach (with my soon to be acquired KX3)!  It also could solve a lot of
problems I have putting up an antenna when operating from my motorhome.

I think this antenna has certain advantages over something like a Buddipole.
The disadvantage might be that you really can't (easily) use it as a
horizontal antenna, but horizontal antennas at relatively low heights don't
generally perform that well in my view.  As a vertical antenna I suspect the
Bravo 7K is apt to be more efficient.  From a portability standpoint, I
think they are at least equal.  By the way, I have a Buddipole as well.

Hopefully I'll get a chance to do some more comparison testing soon.  I've
been ailing a bit of late, but better now, and so is the weather!  It's
beautiful today in Tucson--not windy as it has been.

Dave W7AQK


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[kurtisv]

I am looking to purchase the N6BT vertical for our beach house.  I have not had an luck reaching him on email.  Is there a voice number ?