top of page
  • skylarkcolo

The Beverage Antenna is a traveling wave antenna

Updated: Dec 14, 2022

The Beverage is a traveling wave (slow wave) antenna like the fast wave Rhombic, if it's not terminated it will be bi-directional, if it's terminated it will be directional and a true beverage. A BOG (Beverage on the Ground) is not a Beverage, just laying out a couple hundred feet of wire out on the ground is not a beverage antenna, and it will not be effective for many of the reasons. Laying a wire on the ground sounds very easy, but there are better solutions for receiving if that's all you're going to do.

The inventor was Harold Beverage 1921.

Most Hams don't know that a key concept with traveling-wave type antennas is that there are no standing waves on the antenna itself, which means that the current and voltage levels are the same everywhere along the antenna conductors. That type of antenna therefore has the distinct advantage of working over very wide frequency ranges. By using switches to change between antennas there is No waiting for a rotator to turn, just every direction, every band, every time, by selecting the proper antenna. The antenna wire and the ground under it together can be thought of as a "leaky" transmission line (slow wave) which absorbs energy from the radio waves. The velocity of the current waves in the antenna is less than the speed of light due to the ground. The velocity of the wavefront along the wire is also less than the speed of light due to its angle

The Beverage antenna relies on "wave tilt" for its operation. At low HF frequencies, a vertically polarized radio frequency electromagnetic wave traveling close to the surface of the earth with finite ground conductivity sustains a loss that causes the wavefront to "tilt over" at an angle. The electric field is not perpendicular to the ground but at an angle, producing an electric field component parallel to the Earth's surface. If a horizontal wire is suspended close to the Earth and approximately parallel to the wave's direction, the electric field generates an oscillating RF current wave traveling along the wire, propagating in the same direction as the wavefront. The RF currents traveling along the wire add in phase and amplitude throughout the length of the wire, producing maximum signal strength at the far end of the antenna where the receiver is connected. Laying on the ground will probably not work will at all and force you to add an additional preamps, but at 6" to a foot things come alive. Induced current and changing ground will definitely affect this antenna. These in antenna are all about signal to noise, or Relative Directivity factor. RDF is the antenna gain in the forward direction divided by the gain in all other directions. It is also part of the signal to noise improvement factor (SNIF) I have had a number of 1500 foot beverages up over the years, at one time I had six 2 wire switchable antennas up. But remember, that Capture area or Effective Aperture is determined by antenna gain and the wavelength, not by antenna physical size.

I started putting them at 3 foot high but the deer always got them. So I hung them up about 10 foot and they would droop to about 7 foot high in the between supports which I put up about every hundred feet. I drove steel T posts in the ground to about 4 foot and then put 2" PVC pipe 10 ft long over the top of them, it makes a great support. They have to be run in straight lines, I find the shortest beverage that is really effective for me was at least 500 feet for 80 meters and 1000 foot for 160 meters, and those are elevated off the ground. Much shorter and you're probably wasting your time, if you don't have the space I would go with a small Magnetic loop, Flag, active vertical and others. Sure you can hear signals on shorter beverages but they're not really a true beverage, if they're much shorter than a one wavelength. You can stack 2 or more shorter ones, and the reception improves and the you canantenna pattern changes are small, I would start with 1/2λ or more for phased Beverages. You need to think about effective aperture or what hams call "capture area" it has to be large enough for the external noise to override receive system internal noise. Military telephone wire will definitely work, the resistance isn't really going to hurt you much on a traveling wave antenna, after all you plan on terminating them.

You may not want to waste your time if you can't get one or two wavelengths for directivity on your lowest band, there may be better solutions, like M-loops and others.

Too small of an effective aperture (short antenna) the internal noise starts to dominate the signal-to-noise. Effective Antenna Area, which can also be measured on antennas in the field, by comparison with known antennas. You should also read and understand Friis Equation or the Friis Transmission Formula.

You'll need a 9 to 1 balun for the beverage. Your terminating resistor needs to be a non inductive type resistor (very important). It doesn't have to have a very big value since you're not transmitting on it, how ever expect them to burn up in lightning storms where there's a ton of induced current or differential potential. You're dealing with a very long piece of wire. A standard variable resistor is not what you need, it has to be non-inductive, the value is not too critical somewhere between 300 and 600 ohms will work, it's not critical at all for receive.

The ground system mainly provides an RF and lightning ground. Having a very low ground-resistance is not especially important. The antenna needs a stable ground, not necessarily a low-resistance ground. If you are in an area that has large T-storms you can expect your 9 to 1 matching Network to be blown apart, so I currently use larger toroids and I haven't had any issues in the last few years. I use RG59 or RG6 cable TV coax and F Type connectors which is very cheap, and I have had runs of 500 feet or more to my main control boxes.

A Rhombic reduces E-field gradient at the high the voltage points of the antenna. It solves the problem where antenna tips or ends were charged by a transmitter with very high voltages. A similar effect occurs when receiving when the environment around the antenna is charged from inclement weather. The very high voltage gradient between the antenna and the air around the antenna causes corona discharge. Which appears as a hissing, whining, sizzling, or popping noise in the receiver. The most intense charge buildup occurs at the highest point, farthest from earth and at a point away from other objects in open space. The shape of a Rhombic minimizes protrusions, and places a blunt edge towards the highest charge gradient areas alone the antenna. An yagi or dipole element, on the other hand, has protruding points that extend well out into clear air where charge density and voltage gradient is highest.

During periods of inclement weather when precipitation static is highest, the horizontally polarized quad style element will not only have minimal exposure to high field gradients, the high impedance corona noise will not be as well matched to the receiving system. Less RF energy will be transferred into the system.

Baluns should have an inductive reactance that is 10 times the impedance. Using 50 ohm coax go for 500 ohms. The impedance of the Beverage wire is 500 ohms so we’d like to see the balun present 5000 ohms of reactance. With the losses at the terminating resistor end of a Beverage have somewhat less effect on signal output than losses at the feed end of the wire so you can use 5000 ohm down to 2500 ohms.

A dual-wire variant is sometimes utilized for rearward null steering or for bidirectional switching. I worked 200 countries on 160 meters and I would not have been able to do it without the beverage antennas. They are still my go-to antennas for use on my diversity receive setup for 160-40 meters. see,Diamond%20Logo%20is%20in%20fact%2C%20a%20Rhombic%20antenna.

119 views0 comments

Recent Posts

See All

Roy W7YRU had a 8 element full size Sterba Curtain at 200 in AZ, ss He also had six 20 meter sterba curtains at 120' high

Post: Blog2_Post
bottom of page