Not Every HF Antenna Is a Compromise: Define the Job First
Not Every HF Antenna Is a Compromise: Define the Job First
Calling an antenna a “compromise” says almost nothing. Name the contact, frequency, path, pattern, site and loss budget first; only then can we say what a design gives up and what it achieves.
“Every antenna is a compromise” has become an escape hatch. It can end the discussion before anyone defines success. A 40 m antenna built for reliable short-range work is not defective because it is not the best long-path DX antenna. A low-angle vertical is not defective because it rejects the high-angle energy another operator wants. These are different jobs.
Joeri’s point: an antenna is a purposeful transducer, not a morality tale. No design wins every metric, but no design is automatically compromised merely because it optimises a different one. State the objective and constraints, then measure the complete installed system.
Why Mark’s video belongs here. In “All Antennas Are a Compromise.” — MYTH!, Mark K3ZD of Ham Florida Man directly credits Joeri/ON6URE and RF.Guru while discussing how feedpoint voltage and current, height, ground coupling and transformer ratio can change an installed antenna system. The useful agreement is the challenge to the empty “compromise” label. The boundary is equally important: a comparative result belongs to the named geometry, load, loss and measured pattern—not to an antenna label by itself.
Start With the Contact You Want
The focus here is the everyday HF wire system: dipoles, doublets, loops, off-centre-fed and end-fed wires, inverted-Ls and verticals. Before choosing one, write down the job in operational terms:
- Frequency: one narrow band, several harmonically related bands or continuous coverage with a tuner?
- Path: local or regional high-angle work, a particular DX bearing, broad azimuth coverage or several incompatible paths?
- Availability: maximum signal on one band, fast band changes, weather resilience or dependable operation with minimal adjustment?
- Site: available height and span, soil and terrain, nearby conductors, cable route, support strength and permitted visual footprint?
- Station: transmitter power and duty cycle, tuner range, feed-line length, receive noise, common-mode control and maintenance access?
An antenna that satisfies the declared job is a successful design even if another antenna has more gain in a direction that is irrelevant to that job. Conversely, a beautiful SWR curve is not success when the installed pattern misses the path or the matching system consumes useful power.
Translate the Objective Into Measurable Quantities
| Question | Useful quantity | Evidence that belongs with it |
|---|---|---|
| Does power reach the antenna? | Accepted power and loss in feed line, tuner, transformer, conductors and ground return. | Calibrated reference planes, complex impedance, component loss and representative power/temperature tests. |
| Does energy go toward the desired path? | Realised gain, azimuth/elevation pattern and polarisation in the required direction. | A complete installed model plus controlled field or link measurements where practical. |
| Does it cover the required frequencies? | Impedance, tuner range, feed-system loss, pattern and component stress across the operating set. | Band-by-band sweeps and load/thermal records—not SWR bandwidth alone. |
| Does it receive the wanted signal clearly? | Signal-to-noise ratio at the receiver under fixed settings. | Fast A/B/A comparisons that record signal, noise, overload state, common-mode current and propagation variability. |
| Will it remain usable? | Mechanical margin, weather resistance, electrical safety, RF exposure, inspection and repair burden. | Declared materials and hardware, site loads, local rules and a maintenance record. |
IEEE 145-2025 establishes definitions for antennas and systems that incorporate them. Those distinctions matter: directivity, gain, radiation efficiency, polarisation and pattern are related, but they are not interchangeable scores.
Pattern Comes From Current and the Complete Installation
Time-varying current on the conductors produces radiation. Geometry and current distribution therefore belong at the centre of the decision. Height expressed in wavelengths, ground properties, slope, bends, nearby structures and the return conductors all influence the installed pattern. Raising one part of a wire does not guarantee a lower elevation angle on every band, and “current maximum higher” is not a complete pattern prediction.
If two isolated wires have the same geometry and the same complex current distribution, they produce the same far field regardless of what their feedpoints are called. In a real station, moving the feedpoint or changing the transformer can alter that current distribution through the return path, feed-line exterior current, nearby coupling and loss. That is why centre-fed, off-centre-fed and end-fed versions cannot be declared identical—or ranked—without the installed current system.
The current ITU-R BS.705-2 antenna library provides patterns only for declared antenna geometry and conditions. The lesson for an amateur installation is simple: pattern evidence needs a model that actually resembles the site.
Efficiency Is an Accounting Exercise
Radiation efficiency compares power radiated by the antenna with power accepted at its terminals. Station performance also includes losses before that plane: feed line, tuner, transformer, connectors and any unintended return path. A good match at the transmitter can coexist with substantial loss, while a mismatched low-loss line can still deliver most of the available power to a suitable matching network.
The ITU Radio Regulations define e.i.r.p. in a given direction as power supplied to the antenna multiplied by gain relative to an isotropic antenna. In logarithmic units, upstream losses must first be deducted from transmitter power and the antenna contribution must be gain in dBi for the stated direction. “Transmitter watts minus losses plus antenna gain” is safe shorthand only after those planes, units and direction are declared.
This also removes the temptation to make one topology a universal winner. A ladder-line doublet may keep line loss low under severe mismatch but impose routing and balanced-tuner constraints. An EFHW may solve a support problem but demand careful transformer, voltage and return-path qualification. An OCF may give useful multiband impedances while its asymmetry makes the installed common-mode path important. Each can be excellent in the right loss budget.
Matching and Common-Mode Control Are Different Jobs
An impedance transformer changes the differential load presented to the feed line. A choke opposes unwanted current on the feed-line exterior or another common-mode path. One label does not prove both functions.
For a deliberately unbalanced installed antenna, my practical default is to select an UNUN from the measured complex load and use a separately characterised choke at the measured end of the intended return path. There is no universal transformer ratio, coax length or choke distance. A suitable current balun remains valid for a genuinely balanced installed load, and an integrated unit can be valid when transformation, balance, common-mode impedance, differential loss, voltage, current and temperature have all been demonstrated.
Roy Lewallen, W7EL, explains in Baluns: What They Do and How They Do It why current on the outside of a coaxial shield is a distinct imbalance current. Measure that current along the installed route; do not infer it from antenna name or SWR alone.
Bandwidth Is More Than an SWR Window
An SWR window tells us about impedance at one reference plane under one configuration. It does not reveal radiation efficiency, feed-line loss, transformer heating, common-mode current or pattern stability. A multiband wire can remain easy to match while its lobes divide and move with frequency. That may be useful if a lobe serves the desired path—or useless if a null replaces it.
Define bandwidth for the job. It may mean a frequency range over which the transmitter is comfortable, the matching system remains efficient, component voltage and temperature stay within limits, and the desired realised gain or receive SNR remains acceptable. These boundaries need not coincide.
The Site Can Reverse the Ranking
HF performance is a link, not an antenna beauty contest. ITU-R P.533-14 predicts HF circuits using frequency availability, signal level, noise, time/frequency spread and reliability. An antenna with more modelled gain at one elevation angle may lose the real contact when terrain, bearing, ionospheric support or local noise favours another pattern.
Receive comparisons need equal discipline. ITU-R P.372-17 treats atmospheric, galactic and man-made noise as distinct, variable inputs to system performance. A quieter S-meter reading is not automatically better reception: record the wanted signal as well as noise, keep receiver settings fixed and check that neither configuration changes overload or common-mode pickup.
Mechanics, Safety and Maintenance Belong in the Specification
Antenna optimisation is not complete when an electrical model converges. Supports, wire tension, wind and ice, UV and moisture exposure, connector strain, water paths, access and repair time determine whether the system is available when needed. A modest antenna that stays aloft and can be inspected may satisfy the operating objective better than a higher-gain arrangement that cannot be maintained.
Keep antennas, masts, ropes and tools away from overhead electrical conductors; use a competent installer where site or support work demands it. The official OSHA electrical-safety guide illustrates the overhead-line hazard, but its distances are United States workplace guidance rather than a universal amateur-radio rule. Preserve protective earthing, bonding and lightning/surge measures when testing RF return paths. Assess RF exposure for the actual power, duty cycle, frequency, pattern and accessible area under the rules that govern the station; the ICNIRP 2020 RF exposure guidelines provide an authoritative framework, while the applicable jurisdiction decides compliance. A tuner, choke or counterpoise is not a substitute for any of those safety systems.
Different Antennas, Different Useful Jobs
| Architecture | Reason it may fit the objective | Evidence still required |
|---|---|---|
| Single-band centre-fed dipole | Simple current distribution and a pattern that may suit a declared height and bearing. | Installed pattern, feed-line exterior current, loss, mechanical span and band coverage. |
| Doublet with open-wire line | One wire can support several bands with low line loss when routing and matching are suitable. | Load range, tuner loss/stress, line balance, spacing from structures and band-by-band pattern. |
| End-fed half-wave or end-fed long wire | The feedpoint may solve an access or support constraint. | Complex load, transformer loss/stress, intended RF return, choke boundary, line loss and pattern. |
| Off-centre-fed wire | Selected dimensions may present usable impedances on several bands. | Actual transformation, feed-line loss, common-mode path, current distribution and pattern. |
| Vertical or inverted-L | Vertical current over a suitable return system may serve low-elevation paths within a compact footprint. | Ground/radial loss, surrounding coupling, elevation pattern, matching loss, bandwidth and safety. |
| Loop | Available supports and the desired broadside or multi-lobed pattern may favour a closed wire geometry. | Height, shape, feed method, loss, common mode, polarisation and pattern on every operating band. |
None of these rows names a champion. That is deliberate. The correct comparison is between complete installed systems trying to do the same job under the same constraints.
A Decision Process That Produces Evidence
- Write the objective. Name bands, path, bearings, elevation needs, operating time, required reliability and receive or transmit priority.
- Write the constraints. Record supports, height, span, cable route, tuner and power limits, neighbours, access, safety and maintenance.
- Model the complete conductors. Include radiator, radials or counterpoise, mast, ground model and deliberate feed-line participation.
- Build the loss budget. Use measured complex loads and component data for the feed line, tuner, transformer, conductors and ground return.
- Map common-mode current. Identify the intended RF return and measure exterior current at several positions before choosing a choke boundary.
- Compare at the right plane. Use equal accepted power for transmit field trials and fixed receiver conditions for SNR trials.
- Restore and repeat. A/B/A testing helps reveal propagation, receiver state, cable movement, soil and temperature changes.
- Inspect over time. Recheck tuning, current, temperatures, hardware, water paths and mechanical condition after real weather and duty cycles.
Primary and Authoritative Sources
- IEEE 145-2025: current definitions for antennas and systems incorporating antennas.
- ITU-R BS.705-2: current HF transmitting/receiving antenna characteristics and declared pattern models.
- ITU-R P.533-14: in-force HF circuit prediction method covering frequency availability, signal, noise and reliability.
- ITU-R P.372-17: in-force atmospheric, galactic and man-made radio-noise framework.
- ITU Radio Regulations, 2024 edition: definitions of antenna gain, e.i.r.p., e.r.p. and power supplied to the antenna.
- Roy Lewallen, W7EL — Baluns: What They Do and How They Do It: primary explanation of balanced and imbalance currents at antenna feed systems.
- ICNIRP 2020 radiofrequency exposure guidelines: exposure quantities, averaging and reference-level framework from 100 kHz to 300 GHz.
- OSHA — Electrical Safety: official United States workplace guidance on overhead-line and electrical hazards; local rules remain controlling.
Joeri’s Bottom Line
I am not claiming a perfect antenna that wins every imaginable contest. I am objecting to language that avoids the engineering. “Compromise” has meaning only after we state what matters and what is constrained.
Choose the pattern for the path. Account for every loss at a declared reference plane. Treat matching, balance and common-mode suppression as separate functions. Include noise, mechanics, safety and maintenance. Then test the installed system against the job it was built to do. That turns an argument about antenna labels into a decision we can measure.
Mini-FAQ
- Is every HF antenna a compromise? Only relative to a stated objective and constraints. A design that deliberately serves one path, band set or site is not defective because it does not optimise a different job.
- Which metric should I compare first? Start with realised gain or receive SNR in the direction and frequency range required, then account for accepted power, feed-system loss, common mode, reliability and safety.
- Does a low SWR prove an efficient antenna? No. SWR describes impedance mismatch at a reference plane; feed-line, tuner, transformer, conductor and ground loss can still consume power.
- Do centre-fed and end-fed versions of the same wire have the same pattern? Only if their complete complex current distributions are the same. The installed feed, return path, feedline and surroundings can make them different.
- Is one antenna inherently quiet on receive? Not from its name alone. Compare wanted-signal-to-noise ratio with fixed receiver settings and check pattern, local field coupling, common-mode current and overload.
- How do I choose between a doublet, EFHW, OCF, loop or vertical? Define the desired path, bands and site; model the installed pattern; measure load and losses; verify common-mode current, stress, safety and maintenance; then compare complete systems.