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Author Topic: My Real World Beverage Receiving Antenna Comparisons  (Read 3036 times)
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K1JJ
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« on: February 18, 2020, 08:51:02 PM »

I also co-posted this in the Antenna section for the reading archives.


Background:

A Beverage antenna on the lower bands (160-75M and sometimes 40M) can help you dig down deeper to the next receiving level of weaker stations.  If you have the room and can string one away from obstructions like houses and other antennas, a receiving Beverage can compete with the best of bigger, elaborate antennas, like Yagis, vertical arrays, etc..

I've had a 600' Beverage at 6' high strung to the NE for years covering Europe. The feedpoint is 1000' from the shack away from all noise or antennas, metal, etc.   However over the last 10 years the mice have been chewing up my underground coaxial cable. I got tired of splicing in new coax so I just installed elevated open wire spaced 6" apart feeding the Beverage. This solved the mice problem. It required a 1:1 balanced to unbalanced toroidal transformer at the Beverage feedpoint and a 9:1 stepdown balanced to unbalanced at the coax shack feed. I have a flat match of 50 ohms at the shack receiver.  A full coax run is easier if openwire is not your thing. The Bev is terminated at the far end with a 450 ohm resistor to ground to suppress reflections and give it a ~ 20 DB f-b ratio.  There are plenty of Bev designs on the web.


Comparisons:

During prime nighttime condix into Europe I found the Beverage to have about 5-10 DB BETTER S/N ratio than a 75M dipole at 90' broadside to Eu. There were times I could not hear the Eu station on the dipole but clearly on the Bev. It was all about noise reduction and the front to back of the Bev.

I then tried the Bev compared against my main transmitting antenna, a pair of full size delta loops at 190' high on a 40' boom. This is the equivalent to a 3 el full size 75M Yagi at 140'. The loop array's average height and computer modeling shows the same pattern and take-off angle as the Yagi.

The Beverage had a slightly poorer S/N ratio when compared to the loops at about 12:00 midnight last night into Eu. However, later on when the Europeans were in full daylight (1-2 AM EST) the Beverage was actually 5 DB BETTER in S/N than the loops!  I've never seen this before since the loops were always better in the past. This tells me the Bev system is working well.

So now that I see the two antennas are near par for receiving in prime time, I combined them together in a dual diversity sync'd receiving system. The FT-1000D has a mod to control the two internal receivers in sync and have the Bev in one ear and the loops in the other. (using quality stereo headphones)  It actually sounds like a stereo FM station with the trippy phase noise drifting back and forth between ears. Stations get a stereo sound to them even though they are mono. It's all about the RF waves coming in at different times on the separate antennas. (phasing)  

I then tried A/B tests with the loops alone, the Bev alone and then the two combined in diversity.  There is no doubt I can hear the weak ones better in diversity!  Receiving resolution and word articulation is definitely improved. This is most of the time, not just a fluke fading event.  

The real integration happens in the brain, just like when combining two ears or two eyes to hear or see in 3D.  Research shows, just like using binoculars vs: a monocular, there is about a 41% gain in resolution. I feel it is similar in dual diversity receiving.

The real test is trying to pick out the words of a VERY weak station almost in the noise. Euro accents can make it even more difficult. But there is no doubt that when conditions are good and the two antennas are working and adding well together to complement, there is a receiving edge to be had over a single antenna/ receiver.  Just picking out 50% of the words can sometimes allow the brain to fill in the blanks enough to finish a QSO successfully.

I wanted to pass this info along since it works just as well for AM operation in case someone wants to do something like this himself. A standard dipole and Bev works FB. With the new SDR dual receivers it is a FB project.   I have used Bevs (and dual diversity) for west coast AM DXing for years and they work.


Tom, K1JJ
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WBear2GCR
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« Reply #1 on: February 19, 2020, 02:19:13 PM »

Most excellent information!

I'll do my best to keep my schedule open as to when you will be arriving to help install
that antenna system at my QTH? In this way we can do a valid comparision
between your results and mine.  Roll Eyes

Anything to help a fellow ham.

                  _-_-

PS. my antennas might be the equivalent of a full size yagi at 10ft in a metal barn? Cheesy
(no not really, but it sounds funny...)
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Steve - K4HX
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« Reply #2 on: February 19, 2020, 10:41:36 PM »

Good stuff Tom. I can verify that the Beverages and diversity reception make a big difference. I've heard much the same on 40 meters with my phased Beverages and the two-element delta loop array. I would have never put either of those up without your prodding and encouragement. And yes, they are useful for many AM contacts too.
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« Reply #3 on: February 24, 2020, 12:44:43 AM »

I have a slightly sloping single beverage wired to my HK Mohawk RX-1 and it is much quieter than my vertical and use it as my main receiver.


Phil - AC0OB
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W2PFY
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« Reply #4 on: April 02, 2020, 12:59:40 PM »

Good stuff Tom, up at my hunting camp I lease 144 aches of land from a paper company where myself and members of my club do some hunting and that land is very handy for setting up a beverage antenna.

I once had one laying on the forest floor and I was blown away on how well it received signals out of Europe below 550 kHz. It didn't start out to be a beverage but a long wire antenna waiting to be put up that never happened. The reason it never happened is the paper company logs out parts of the property about every 7-8 years and I had to pull it up one year and never put it back up or down.

I have no problem putting up a wire to the west or northwest but to the east is a border problem with neighboring property that is a field where horses graze.

I have seen a beverage system that is bi directional online and I think I try that setup. As I recall the return from from the far end is retrieved with RG-6 TV cable that is amazingly cheep at most outlets such as Home Depot.  It's something like 30 bucks for 500 feet. I guess my point is that if you don't have room to put one up in one direction, there is another way to do it by setting up a twin beverage with relays etc in the direction that you do have room.    
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« Reply #5 on: April 02, 2020, 03:16:06 PM »

Hi Tom,

I have a homemade K9AY, Gary's arrangement and it works ok. Seems like the F/B displayed acts more like diversity as it is inconsistent. I ran your dimensions and indeed for what it is worth EZNEC validates a F/B of 20 dB. I think I will try a Beverage this summer.

Alan


* BEV_600ft_6ft.jpg (24.85 KB, 529x379 - viewed 183 times.)
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Steve - K4HX
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« Reply #6 on: April 02, 2020, 03:34:20 PM »

You can make a two direction Beverage with two wires (some use ladder line or similar) and a reflection transformer at the far end. The nice part of this set up is that you can adjust the termination resistance for best directivity right in your shack.

http://www.ae5d.com/bev/bev2.html


Some good previous threads.

http://amfone.net/Amforum/index.php?topic=18760.25


Tom's broadside 600 footers modeled attached below.




Info on my K9AY and Beverages here.

http://www.amwindow.org/misc/huzantennas/antennas2014.html


* 80M_600'Bev_VertPattern.jpg (198.29 KB, 604x603 - viewed 185 times.)

* 80M_Bev_600'_HorizPattern.jpg (192.2 KB, 604x603 - viewed 189 times.)
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