I have a discussion of the 43 ft vertical on our club website www.sdxa.org
Click Articals to see it. In addition, I think it is not often realized
that the coax feedline outer shield acts as one of the radials going into
your station unless you use an effective line choke on the feedline where
it leaves the radial field edge. Not only that, the noise in your station
from wallwarts and other things will be conducted out to your vertical
system. It would be wise to use a line choke where the vertical feed line
leaves your station
Applying a few ferrrite beads will help but much better results will be
obtained if you build high quality chokes as described on K9YC web site
using multiple turns (square law applies to turns thru the core). I have
built many chokes of this type and measured their performance with my
equipment confirming his results.
If you would rather buy such chokes, check out Balun Designs. If you
build your own, you can see excellent pictures there.
I have not dealt with them so you might want to check them out at eham.net
Dan, N5AR
On Sat, Apr 5, 2014 at 11:32 AM, Dan Schaaf <dan-schaaf@att.net> wrote:
> I installed a 6 BTV with 45 radials and needed to adjust the 15 meter trap
> calibration. Was easy according to DXE instructions. I found it's
> performance to be quite good compared to my HyGain AV-640 which performs
> really well. In A/B tests, I saw little difference.
>
> From things that I have read, the 43 ft vertical has different takeoff
> angle depending on band since in some cases it is 1/4 wave long and in
> other cases it is not. Whereas the band resonant BTV should be consistent
> in takeoff angles for each band since each band is tuned as a 1/4 wave .
>
> I was able to work some long haul DX such as Bangladesh during long path
> conditions on 40 CW. The only problem is that on the lower bands like 40
> and 80, it has a very narrow bandwidth, so you must pick a band segment of
> interest and adjust it's length for that segment.
>
> Ultimately, I built my own vertical which is 69 ft tall and covers 80, 60,
> 40 meters and 160 with base tuning and a 60 meter trap. 40 meters ends up
> being 1/2 wavelength and the other bands are 1/4 wavelength.
>
>
>
> Best Regards
> Dan Schaaf
>
> =================================
> K3ZXL www.k3zxl.com
> =================================
>
>
> -----Original Message----- From: Matthew King
> Sent: Friday, April 04, 2014 8:22 PM
> To: TowerTalk@contesting.com
> Subject: Re: [TowerTalk] Hustler 6-BTV installation
>
>
> Hi, Phil - I found on my installation of a 6-BTV that trap tuning was
> necessary to get the best tuning over my 45 radial field.
>
> I used a bulkhead for some time until I installed a DX Engineering choke in
> an effort to knock out some RF in the shack. I've come to the conclusion
> that I'm just at the edge of the near field since the choke made little
> difference on 10m. Point being, I guess it's really up to you and your
> particular installation as to install the beads or not. It cannot hurt
> from my somewhat limited understanding, and may very well help.
>
> Might I ask why you've decided to switch to a shorter, trapped vertical
> rather than the 43' vertical? Also, did you have a tuner at the base of
> the 43' antenna?
>
> Take care,
>
> Matt King
> KK4CPS
> _______________________________________________
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Dan Hearn
N5AR
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