Hello Kenny
I have been playing around with antennas and feedlines over many years
and have found that your ears cannot immediately tell the difference
between a 1 dB change due to fading, atmospheric noise variations, QRN
etc. I have had scalar and vector analyzers over that time to determine
gain and loss improvements with some accuracy. A 1 dB change is very
hard to nail down with a quick A-B test. If you listen over a week or
so, you can tell that a 1 dB change in your system made a difference. If
you have a 2 dB change, it is immediately noticeable with A-B
comparisons. That does not mean that you should not worry about any
losses in your system. Get rid of any loss. They do add up.
One thing I noticed was that hanging ferrites all over my beverage
feedlines was a huge help in keeping noise low in your system. You would
be surprised at how much noise comes in your receiver from the wrong
place! I put two ground rods at the transformer end of the beverage
separated by about 25 ft and outfitted with plastic boxes with toroids
and the feedline wrapped around it for each spot. I also put more
toroids and ground rods where the feed lines enter the building. There
are toroids all over the place and I live out in the country! See
ON4UN's Low Band DXing 5th edition. Joel is right in that you must
install the beverage properly. I am no expert on 160 meters, but Joel
sure is!!
Dave K1WHS
On 8/24/2022 9:03 AM, w5zn@w5zn.org wrote:
Hi Kenny,
Over the past 12 or more years I've conducted numerous comparisons of
different receive antennas on the low bands. I'm fortunate to have
enough land to lay all of them out with adequate spacing and perform
A/B comparisons. I am in a rural area that is relatively quite
although over those 12 years I have seen the noise floor gradually
increase up to 5 dB in a couple of directions! A battle I continually
fight!!
One thing I have emphasized over the years is the realized performance
of any antenna will be different depending on the geographical
location. Another point is most times radio amateurs have unrealistic
expectations of what the performance of a specific antenna will be.
With that said, I have compared the antenna you are considering at
your QTH here at W5ZN with a single Beverage that you currently use. I
could not document any noticeable improvement between the two. That's
not to say there wasn't any improvement, it just was not noticeable.
I begin to notice a difference when the RDF is increased by more than
1.5dB. I realize this is splitting hairs when we're claiming only a
few tenths of a dB difference but that is based on my real world
documented comparison.
The most significant improvement I have documented is moving from a
Beverage to a phased vertical array. The Hi-Z and BSEF 8 vertical
arrays are the top, with the HiZ outperforming the BSEF by just a tad
due to the HiZ-8's improved F/B and F/S performance. The YCCC-9 is
also an excellent performer. My measurements have also confirmed the
modeling data for all of the arrays. I presented this data at Contest
University - Dayton this year.
So my recommendation is to erect the new Beverage and give it a try.
You may very well notice a improvement. If constructed correctly, it
should be an improvement even if only a few tenths of a dB RDF and it
won't be a loss !
73 Joel W5ZN
On 2022-08-23 14:07, Kenny Silverman wrote:
In a rural area with no significant man made noise, if you redesign a
beverage for better RDF when do you start to notice a difference?
I’m considering upgrading my single EU beverage at 625’ (190m) to a
pair in echelon where will each be 550’ (168m) with 20’ (6m) spacing
. The increase in RDF is 0.8 dB - will it be noticeable?
I realize if there’s noise in a direction where you reduce the energy
you will better hear the difference , but my EU beverage is quiet.
Though the F/B change will help with thunder storms off the back.
Overall I tend to receive better than I transmit to EU.
73 , Kenny K2KW
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