...... I had decided long ago that the only way I was going to be able to hear (and work) the weak European stations on 160m was to have myself a Beverage. A Beverage antenna that is.
After reading countless articles and watching a YouTube presentation video on Improving 160m and 80m Antenna Performance I finally decided on a Reversible Beverage On the Ground (RBOG). Essentially that would give me the benefit of two directions using the same space as one beverage as well as not needing to be as long nor elevated from the ground. The wire just lays right on the ground, sometimes over a small fallen tree, but otherwise on the ground. Of course this approach does come with an inherent reduction of gain and an increase in angle of reception, however a compromise was the path I chose.
As soon as I had the antenna setup and tuned to 160m I was amazed at the difference I noticed immediately when I flipped the power switch on the pre-amplifier and a Slovania station that I could otherwise not hear well enough to work was now coming in with a strong enough signal that I felt I could now work them. Now actually working them was a different story as I quickly rushed to tune the transmit side of the house (antenna tuner on the doublet and the amplifier) only to find the signal had died out. Solid state amps and tuners do have their advantages, but that is the way it goes sometimes.
No need to worry though as later in the evening after the sun had set I tuned in and worked a Romanian and German station that I otherwise would not have even heard to work before the Beverage. It was already paying off in spades and after going back out today (the day after installing the Beverage) and getting exact coordinates on the feed end as well as the 'terminated' end and plotting on Google Earth, I came to realize that I had only ran a 161 feeet of wire for the antenna. That being just inside the length that they recommend with a BOG (between 160 and 200 feet).
Suffice to say the addage often tossed around; "a short beverage is better than no Beverage at all", seems to be very true. Simply increasing the received signal by approximately 6db (One S-unit) and in turn decreasing the noise floor was the difference in me working Europe and prior to the antenna installation, not even knowing they were there.
Below are various photos of the installation. Yes, it could very well be altered to increase performance, and possibly at a later time I will do just that. Matter of fact, I think I will be experimenting with an additional ground rod placed about 500 feet out and splicing the wires and extending the existing Beverage in the hopes of grabbing the 10db gain listed above. Just depends on whether I think the additional 4db is worth the effort and materials.
The three photos below show GPS positions and distances of the terminating end, feed end, as well the distance from the doublet, my main transmit antenna (long yellow line). The red line represents a planned future RBOG to cover from NW to SE (Alaska). Bear in mind that the distance from the transmitting antenna is approximately 1/4 λ - which is far closer than most would recommend, however I do not seem to have a problem so far (the kenwood TS-590S has a dedicated RX RCA jack and switches the circuit open on transmit) and I am willng to risk it based on my unique sittuation (buildings sheilding path, height of transmit antenna, etc.. ). Generally the further the better for reason other than possible receiver overlaoad as well, such as the transmit antenna transfering noise to the beverage via coupling, re-radiating, etc..
Coax running on the ground, over fallen trees, etc.. over to the feed end of the RBOG. Next photos are of the 16/2 Lanscape Lighting Wire, and finally the far end conection. The ground rods are actually 8 foot long and leaving approximately 1.5 foot above ground will allow me to go back out and paint the upper portion of the rod with white or orange paint so that they are not likely to trip me up when out in the woods hunting or - well - running more antenna wires.
Any of the photos can be enlarged to full resolution using the expand icon in the top right portion of the popup window. ESC key will close the windows.
Below is a video example of the low S/N ratio that this short BOG exhibits.
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Below are some composites of signal strength, azimuth, and station locations. Just a work in progress.
|Steve - KD8ZBG||Robert - N1LPE|
|Charles - KE4QEG||Bill - KD8ZBF|
And Maybe A Inv-L For 160m
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Previously I had created a couple of antenna models using the 4NEC2 software however as I slowly continue to learn how to navigate the software and accurately model an antenna I found that my first model was way off, and that would include my assesment of the triangle loop at 1100 feet. Below I have included what I beleive to be much closer to accurate models of my 160m doublet which is 240 feet long and the apex is at or about 75 feet high and fed with 150' of 600 ohm ladder line into the shack and into a Palstar AT2K T-match network with a built in balanced line 4:1 balun.
After creating this current model I tend to believe that it more closely resembles the radiation characteristics that the antenna exhibits through my use and station reports from many different locations. Eventually as I become more familliar with the software I will reintroduce the model for the triangle loop since based on information available in an article on horizontal loops located HERE it would seem that my original model was far from accurate on angle of radiation as well as pattern.
My current doublet @ 1.85 Mhz
My current doublet @ 3.910 Mhz
My current doublet @ 7.200 Mhz
The following is my attempt to overlay the pattern on my property using Google Earth and the radiation pattern on 160 meters. Somewhat crude but might tend to give an idea to other stations as to my signal strength vs radiation pattern.
|CLOSE UP VIEW||EXTENDED VIEW|
*** note that the red is the highest levels of gain, followed by the orange(ish) and then the nulls (or lower gain) being in dark blue ****
If you have any advice or would like to offer corrections to my models then please comment and possibly the beginners like me with this EZNEC software can gain some passed on knowledge.
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After Modeling This Antenna I Have Came To The Conclusion That It Would Be A Massive Waste Of time And Energy - Will Upload EZNEC Data Later
I have been reading and studying the article - "The Long Wire Loop: an Omni Directional, Multiband, Low Angle Radiator Wire Loop Antenna" by Steve Cerwin, WA5FRF which I have uploaded here for all to be able to learn from and have decided to make my next antenna project the 1,100 foot +/- 160m long wire loop in a 40° triangle configuration. Based on the EZNEC performance data presented by Steve I can clearly see why the 500 foot 1 wave length 160m sky loop that I had up once before was not the performer I thought it would have been.
The problem I experienced with my previous attempt at a loop antenna stemmed from the lack of the harmonic properties the loop would have exhibited at twice the wave length to create a null above the radiated signal, thus lowering the take off angle immensely, making it a much better DX performer as well as not being the "cloud warmer" that the 1 wavelength version exhibited even when rag chewing locally (600 to 800 miles or so). I eventually took the loop down and focused on my 160m doublet dipole which was reported to me as being a much better performer.
Today I am still using the 160m doublet at about 75' to 80' at the apex and being fed with 150 feet of 600 ohm ladder line all the way into the shack and terminating at the tuner. It works reasonable well but the data shows that the harmonic loop will outperform the dipole with even lower angles of radiation, and the impedance match will be a comfortable 20 to 200 ohm (easily tuned by either the Dentron Super Tuner or the Palstar AT2K).
The photo above is a depiction of the 160m doublet dipole that I already have up as well as my planned path for the 1,100' loop in the (approx) 40° triangular formation. Although I have 5.56 acres of land to play with, the tract is relatively narrow so making it fit within the confines of the property boundary might be a bit tricky however it is also heavily wooded which should hide it from even the most eagle eyed.
Hopefully I can get this done before winter rears its ugly head .....
Results from EZNEC with the 1100 feet delta loop (sort of) vs my existing 160m Inverted V at 75' height and 240' long
Side by side comparrison of the model and then graph
By the models presented above it seems to show that although the doublet in an inverted v configuration at 75' seems to show a slightly better low take off angle although it falls short of the delta's purported 6.14 gain by just a little over 2db. You may also notice that looking at the graph on the horisontal plane (red) the doublet creates quite a larger overall radius in pattern as well as a more uniform current prediction with the highest current being towards the middle two thirds just as I have read about before. The model seem to have proved that right.
In order for me to create any extremely good low angle of radiation from the doublet I had to raise the apex to approx 240' (1/2λ), a height that is simply prohibitive in the real world and in my case. I should also note that any and all tests that I did with radials below the apex of the doublet (no matter how many or how long) did not alter the pattern save for the least little bit. An absolutely out of the question endeavor considering nothing to be gained.
Corrected Model For 1100' Loop
Any corrections would be most appreciated.
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