Should your antenna be vertical or horizontal?

It matters more than most people assume. A radio wave carries an electric field lying in the same plane as the wire that launched it — stand the antenna up and the field stands up too. That orientation travels with the signal, and the receiving antenna only extracts energy lying in its own plane.

Cross the two on a direct path and you can lose up to 20 dB. Same power, same distance, clear path, and most of it never arrives. One exception is worth knowing: skywave comes back from the ionosphere elliptically polarised, so on HF long-haul and NVIS the orientation barely counts. This is a direct-path rule — VHF, UHF and ground wave.

So which one? Height decides. Below about three metres — a whip on a pack or a vehicle — vertical gives the stronger signal, clearly so up to 50 MHz. Get both antennas to ten or twenty metres and horizontal wins instead. Most portable stations never leave the first case.

Vegetation flips it. Trunks and stems act like a screen made of vertical wires, and wet foliage makes that screen conductive — it absorbs vertically polarised signals on contact. Under canopy, lay the wire flat. And keep it clear of leaves entirely, because wet foliage touching the wire grounds the signal out.

One more difference nobody mentions. A vertical whip radiates the same in every direction, which is convenient when you're moving and means everyone within range hears you equally. A horizontal half-wave is bidirectional — it has two ends that radiate almost nothing. That's not a flaw. It's a choice about who gets to hear you.

Save this for your comms binder.
Send it to someone running a vertical under heavy trees.
Full comms course on the profile.

#hamradio #radio #antenna #polarisation #recon