Friday, January 4, 2019

Beverage experiments

Reading about the "open" beverage PA3FYM uses on 30m WSPR I went very curious. A beverage is for many the ultimate low noise receive antenna for low bands. But why? Well, because the beverage is a extremely inefficient antenna, at least for transmit. It is almost on the ground and therefore does not pick up much noise. "Beverage" sounds difficult but is only the name of the inventor Harold Beverage. Several designs are available and when you look at the diagrams and drawings you ask yourself were to get the parts. But the only thing you actually need is a lot of wire, a lot of room and longwire antennatuner. The beverage is in basically a very long longwire and if a transformer is not available you can use a longwire antennatuner as well. You have designs with a (carbon)resistor to ground at the end and designs with a open end, I think this will only have effect on the directivity a bit.

Johan's setup
A few years ago PE9DX Johan was visiting me and told me he was using the barbwire which is around a farmers field near his house. I showed him I've got a similair field at the back of our garden. I think the field is at least 250m long with barbwire around it. This could be a nice beverage receiving antenne. Johan told me that connect it to a receiver is not that difficult. He sent me some photos from his experiment including a e-mail from PA3FYM about the transformers used. At first sight I thought it was complicated. But reading and asking about it again revealed the project is simple as long as you got the right components. Luckely Johan told me were to get the ferrite (Bakelaar electronics, Julianadorp) and I ordered some BN-73-202 ferrite beads to experiment with. Johan send me some photos as well so I could get the idea. A good idea is to look at this website: http://www.w0btu.com/Beverage_antennas.html to see how things should like. Besides that you can find a lot of beverage info there.
At the shack of PE9DX

So I started creating with some help from the e-mail PA3FYM wrote to PE9DX. Some photos from Johan helped me as well. I made the 1:6,25 transformer and the 1:1 transformer. Then I had other interests and things and forgot the whole project actually.

When I discussed some antenna matters with PD1RP Peter on the PA6AA contest location we saw a big fence just behind the house, I suggested we should try it as a beverage to increase our receive on 160m. It could be a good idea. At least it would be a great experiment...I remembered I still have these transformers around somewere. So, continue with the experiment would be interesting.

Simplified drawing of winding a ferrite bead
Describing all the formula's from PA3FYM and theory would be out of my knowledge. It is far beyond my theoretical ability. But in fact the outcome is that a transformer 1:6,25 on the beverage side + common mode choke and a 1:1 transformer at the other end of the coax in the shack should do the trick with a 1m high fence wire. The 1:6,25 transformer is made with 2 BN-73-202 ferrite beads. 2 windings at the receiver side and 5 windings at the beverage side. Another trick would be to keep enough wire at the 2 winding site and twist it then do 1 winding through another ferrite bead. Coax should be wind through a large ferrite ring before you connect it to the transformer. One side of the 5 windings can be connected to the beverage or in my case the fence wire. The other "earth" side can be connected to a ground rod and some wire radials on the ground. At the shack you connect the 1:1 tranformer made from a BN-73-202 with 4 windings on both sides. Connect it to the coax and at the receiver side try which of the 2 wires connected to earth/receiver give best SNR results, you can try to listen or see in a spectrum waterfall. Switch the wires to see best results.

The finished creation...
Well, very nice. But does it work? Well.....no! I connected everything on the barbwire fence and put a copper rod in the soil as earth. I also connected 2 wires for extra ground radials. My first impression: signals were strong but so is the noise. Actually I find my inverted-V a much better performer. The noise on the "beverage" is at least S8 which is not what I expected. Could it be the fence is too long? Does it pick up too much? Or is the transformer not made right? I went outside again and reversed earth and antenna connections on the transformer but nothing changed. I expected something different from this experiment, a low noise antenna....but so far it is a very noisy antenna.

I made WSPR comparisations at night were I used my inv-V on the IC-706 and the beverage on the FT-817. The inv-V is far better. If any reader does know what is wrong? In theory this setup should work but it doesn't...

Actually 18 spots on the beverage, O25KFP is wrong spot

Inverted-V spots




10 comments:

  1. The holy grail of RX antennas: brings DX, doesn’t take up extra space.

    There is a lot of barb wire surrounding me. So been there, done that, no success. Next I hung up a thin copper wire from a broken transformer along the concrete posts that hold the barb wire. It is 100m long, unterminated but with a 9:1 transformer on the coax side. Doesn’t really work either; I have lots of noise too on that wire.

    I tried a 80m dipole on the ground (DoG) for RX: seems to work on some occasions. But no miracles.

    For over two years I now have two terminated loops (half a K9AY array, in a single 2D plane). One for USA, one for JA/ZL. These DO work great. Especially in diversity reception.

    It’s fun to experiment and try. Maybe one day we’ll hit the jackpot ;o)

    73
    Franki

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    1. Hello Franki, I'm actually glad you have the same experience. So it's not some fault. I think I'll better think about something else, my receive is not that bad on 160m with the inverted-V. There are a lot of operators that use a receive loop that is turnable, it might do a lot better since you can null out the noise. 73, Bas

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    2. I also used a Wellbrook ALA1530 active loop that is rotatable.
      It works really fine but the wire loops work just as well and those are cheap and don't need a motor (with yet one more extra cable running through the garden).
      The active loop also has DC power on the coax which made switching RX antennas difficult in my specific setup (I forgot why now 36 months later HI).
      I did not hear much difference when I rotated the small active loop.
      Just a FYI ;o)

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  2. If your Beverage doesn't work, please see my comments at
    https://plus.google.com/+BasLev/posts/4A6aQ8m44Uf

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  3. Also tried this for LF. It worked, but not spectacularly well. Later, the fields had electric fences installed very (as in incompetently) close to the old fences, so connecting up is no longer an option locally, but there are plenty to try elsewhere!

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    Replies
    1. This fence also has electrical wiring. But it has not been connected for a long while since the owner was selling his property and didn't use the land. Now it's sold but I don't think the new owner does need the electric fence. Besides that my neighbours bought some of the land. 73, Bas

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  4. This year I will try the Beverage, se what I can do with it. Also, I will be trying some small active loop antennas, bade with wire and simple hula hoops.

    Vy 73 de Jan, OZ9QV (also still holding the call PA9QV)

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  5. Hallo Bas, zo een geweldig leuk experiment. Ik volg VA3OSO en hij knoopt ook zijn FT-817 met tuner aan gaaswerken en metalen trappen e.d. en heeft goede resultaten. Ik ben benieuwd naar je verdere experimenten.
    73 Hans, PE1BVQ

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    Replies
    1. Hallo Hans, ik ga VA3OSO eens opzoeken. Jij hebt de trafo's nog gezien afgelopen zomer. Toen had ik ze al klaar maar meestal duurt het even voordat ik weer een experiment van de grond krijg hi. 73, Bas

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Thanks for your comment. Bedankt voor je reactie. 73, Bas