Beverage or BOG? Choose by Site, Pattern and Maintenance
Beverage or BOG? Choose by Site, Pattern and Maintenance
A Beverage on Ground is part of the same travelling-wave family as the familiar low elevated Beverage. Moving the wire onto the surface changes its coupling, loss, velocity, maintenance and pattern—sometimes enough to change which installation is actually useful.
A BOG is not a poor imitation that becomes respectable only after an amplifier is attached. Nor is a full Beverage automatically the better receiving antenna at every station. They are related terminated-wire systems operating in different relationships with the ground. The decision belongs to the site, the required azimuths, the available length and the maintenance you are willing to do.
My practical summary: a low elevated Beverage usually gives more output and can provide a cleaner, more stable directional pattern when the site and length support it. A BOG is faster, lower-profile and often easier to place away from house noise, but it is more exposed to soil, moisture, vegetation and burial changes. Measure forward/reverse response and SNR; do not choose from the antenna name.
They Share a Travelling-Wave Principle
Harold Beverage, Chester Rice and Edward Kellogg described the wave antenna as a long conductor coupled to lossy earth and aligned with the desired arrival direction. A termination at the far end absorbs the travelling current that would otherwise reflect and disturb the unidirectional response. Their 1923 paper discusses both supported wires and an early rubber-covered wire laid across scrub oak and sand.
The family resemblance is therefore real. Both a conventional low Beverage and a BOG use a long wire, ground coupling, a feed system and usually a termination. But “same family” does not mean “same electrical length, velocity, loss or pattern.” Bringing the conductor onto the surface increases dielectric and conductive interaction with the immediate ground. The current attenuates differently, and the installed system becomes more sensitive to what is touching or covering the wire.
Length Must Be Stated in Wavelengths
A claim such as “a Beverage should be 200 metres” is incomplete. Two hundred metres is about 1.2 wavelengths at 1.8 MHz, 2.3 wavelengths at 3.5 MHz and 4.7 wavelengths at 7 MHz in free space. Ground coupling changes the wave velocity and effective electrical length, especially for a BOG.
More length is not a free improvement. It can increase directivity and output over part of the range, but it can also create extra lobes, narrow the useful azimuth sector and increase loss. A multiband receiving installation should therefore be modelled and measured across every intended band, not scaled from one low-band rule.
What Moving the Wire to the Surface Changes
| Property | Low elevated Beverage | Beverage on Ground |
|---|---|---|
| Immediate environment | Coupled to ground but with a more repeatable conductor height | Directly affected by surface moisture, vegetation, leaf litter and burial depth |
| Passive output | Usually higher for comparable useful geometry | Usually lower because stronger ground interaction adds attenuation |
| Pattern stability | Often more stable when height and supports remain fixed | Can drift as the wire settles or the surface changes |
| Deployment | Needs supports, clearance and a visible wire route | Fast, low-profile and easy to reroute |
| Maintenance | Inspect supports, tension, termination and feed system | Also inspect burial, vegetation, moisture exposure and mechanical damage |
| Safety | Can become a clothesline or animal hazard | Less visible but still a trip, snag and maintenance hazard |
N6LF’s measured case is particularly useful because it was not a one-day comparison. His 450-foot insulated BOG initially performed well and then deteriorated over two winters as it gradually sank into the ground. The accompanying modelling and measurements connect the change to increasing ground loss and altered current distribution. That result does not predict every field, but it proves that “laid down once” is not a stable geometry by definition.
The Termination Is an Installed Adjustment
A terminated Beverage is often drawn with one resistor and two ideal grounds. The real termination includes ground-electrode impedance, soil conductivity and permittivity, frequency, wire height, insulation, transformer response and the distributed line impedance. One resistor value cannot be assumed correct everywhere.
Start with modelling or a reasonable estimate, then perform a controlled sweep around it. Measure at several frequencies and compare:
- forward response from the wanted direction;
- reverse response from the terminated end;
- side response and local-noise pickup;
- receiver output with identical bandwidth and gain settings; and
- stability after rain, drying and seasonal surface changes.
The best resistor is not necessarily the one that gives the lowest feedpoint SWR. It is the value that produces the required pattern and useful SNR while keeping the transformer and grounding arrangement within their operating range.
Output Level Is Not the Same as Receiving Performance
A BOG can be many decibels quieter at the receiver than an elevated wire. That alone does not prove worse SNR. If atmospheric and external noise remain comfortably above receiver noise, adding gain changes the S-meter but does not reveal a weaker signal. If the antenna-plus-feedline output approaches the receiver noise floor, then a low-noise amplifier placed at the correct reference plane can preserve system sensitivity.
The amplifier still has to survive the site. Check strong broadcast signals, nearby transmitters, gain before filtering, input compression and intermodulation. Measure noise with a terminated input and with the antenna connected. An amplifier that raises signal and noise together may be working perfectly while providing no SNR improvement.
For the same reason, I do not accept a universal claim that the full Beverage “wins by several dB.” Compare both antennas through calibrated signal paths and record signal, noise, RDF and usable azimuth coverage separately. The best installation is the one that extracts the wanted signal at your site.
Feedline Pickup Can Erase the Pattern
A quiet directional wire can be defeated by a coax shield that collects noise near the house and carries it to the antenna-side transformer. Common-mode control may be needed at the feedpoint, at a boundary along the cable, near the receiver, or at more than one location. The placement should follow a current and noise-coupling map rather than a fixed distance rule.
Useful checks include clamping around the complete feedline at several marked positions, changing the cable route, temporarily powering the receive electronics locally and comparing a galvanically isolated or fibre-linked test path where available. Repeat the original state after each experiment so changing propagation is not mistaken for a feedline cure.
Our Woodland Method—and Its Boundary
At RF.Guru we have often routed insulated BOG wire over fallen logs in woodland and fixed it so it cannot become an elevated clothesline. This makes the route easier to inspect, keeps sections out of the wettest surface layer and can slow accidental burial. It also means the conductor is no longer at one uniform “on-ground” height.
I treat that as a practical surface-supported terminated wire, not as a guaranteed performance upgrade. Log diameter, moisture, spacing and decay all change the local geometry. If repeatability matters, mark the route, photograph the support points, record approximate height and remeasure after seasonal changes.
Low visibility does not mean zero hazard. Obtain permission, avoid public paths and livestock routes, protect feed and termination hardware, use visible markers where a crossing cannot be avoided and inspect after forestry work or storms. Staples and sharp hardware must not create an injury risk or damage living trees.
A Field Comparison That Survives Propagation
- Describe both antennas. Record wire length, conductor, insulation, height distribution, azimuth, transformer, termination, ground electrodes and feedline.
- Use simultaneous channels or fast switching. Slow comparisons confuse fading with antenna performance.
- Calibrate the receive paths. Include preamps, filters, cable loss, ADC scaling and AGC state.
- Record signal and noise separately. The stronger S-meter reading is not automatically the better receive result.
- Test several bearings. Include forward, reverse and side arrivals plus known local noise sources.
- Repeat the baseline. Use A/B/B/A or simultaneous recordings to expose drift.
- Revisit the installation. A BOG that works in summer may not be electrically identical after a wet winter.
Bottom line: choose a low elevated Beverage when you can maintain its length, direction, supports and ground system and the measured pattern rewards the effort. Choose a BOG when rapid deployment, stealth and placement away from local noise matter more—but accept that the surface becomes part of the antenna and must be monitored.
Primary sources checked
Mini-FAQ
- Is a BOG a completely different antenna? No. It belongs to the terminated travelling-wave family, but direct surface coupling changes attenuation, velocity, maintenance and pattern.
- Does a full Beverage always beat a BOG? No. It usually offers more output and potentially cleaner directivity, but installed SNR also depends on site noise, azimuth, feedline pickup and receiver sensitivity.
- Why can BOG performance change over time? Moisture, vegetation, leaf litter, soil contact and burial depth change the conductor’s coupling and loss.
- Does a BOG always need a preamplifier? No. Add gain only when antenna and feedline output do not keep external noise above receiver noise with adequate margin.
- How should the termination be chosen? Sweep plausible values and judge forward/reverse pattern and SNR across the intended bands—not feedpoint SWR alone.
- Where should feedline common-mode control go? At the boundary identified by current and noise-coupling tests. A receiver-end choke cannot undo pickup on the cable section ahead of it.