Why Comparing Antennas Is Like Comparing Apples and Oranges

Antenna comparisons are everywhere — forums, YouTube, field days. And yet most of them are as flawed as they are passionate. Saying “A GAP Titan is 2 S‑points stronger than my end‑fed” may feel like a data point, but without the full picture it’s often meaningless.

Context Is Everything

Antennas are not standalone devices. They interact with:

• Earth/ground: conductivity, permittivity, and radial system
• Height: changes take‑off angle and pattern
• Surroundings: buildings, trees, gutters, masts
• Feed system: coax length/route, choking, baluns/unun

Without these, you’re not comparing antennas — you’re comparing installations.

Polarization and Take‑Off Angle Matter

A GAP Titan is effectively a kind of vertical dipole, offering:

• Low‑angle radiation (great for DX paths)
• Vertical polarization (different noise coupling vs horizontal)

Compare that to a typical 26 m end‑fed with a loading coil, sloped/bent around a garden:

• Awkward, install‑dependent current distribution → mixed H/V polarization
• Often too high an elevation angle on low bands → poor DX
• Suffers from ground loss, common‑mode, and nearby structure coupling
• Coil insertion loss + detuned impedance transformation above its design point → reduced efficiency on higher bands

It may resonate, but it rarely excels. On some paths it’s stronger, on others much weaker — and always highly installation‑dependent.

Signal Strength Is Path‑Dependent

If a station is ~1 500 km away and the ionosphere supports a 10–15° take‑off angle, a vertical with a strong low‑angle lobe will shine. If your antenna radiates mainly at 40–60°, your signal overshoots the skip zone. The reverse can be true for closer NVIS paths.

S‑Points Are Not a Metric

• One S‑point is “supposed” to be 6 dB — most rigs don’t follow it consistently.
• AGC, mode, bandwidth, and firmware skew readings.
• SDR “S‑meters” are often scaled ornaments.

Use real metrics: SNR (dB), SINAD (FM/digital), and repeatable A/B measurements with identical conditions.

Apples to Apples, Please

To make a valid comparison, you must control variables:

• Identical height above ground and similar surroundings
• Known ground quality and radial/counterpoise strategy
• Same feedline length/route, choking, and balance
• Same band, time, and azimuth
• Preferably modeled patterns or measured field strength to explain differences

Otherwise, it’s an anecdote — not evidence.

Takeaway

Antennas aren’t just wires and tubes. They’re systems. Unless you understand and control:

• Polarization (H vs V and mix)
• Elevation‑angle distribution (take‑off lobe vs the path)
• Surroundings & ground (loss, detuning)
• Current distribution (and whether your feedline is radiating)

you’re comparing apples to oranges — or apples to bowling balls.

Bonus Tip

For practical, path‑aware comparisons, use WSPR and/or RBN over several hours with an A/B switch feeding the same receiver. Aggregate dB‑relative reports by distance/azimuth, then repeat on another day. That’s how you build a meaningful picture.

Interested in more technical content? Subscribe to our updates for deep‑dive RF articles and lab notes.

Questions or experiences to share? Contact RF.Guru.