Stealth antennas

What it is

An antenna chosen to be hard to see or easy to take down, for homes where covenants, landlords or neighbors rule out a tower and a beam. There is no free lunch: a hidden antenna is almost always smaller, lower or closer to clutter than an exposed one, and it works less well. The aim is to get the best compromise, not to match an outdoor station.

The options

Option	Why it works	The compromise
Attic wire	Out of sight, protected from weather	Shingles, wiring and ducts absorb and re-radiate; noise from household electronics
Window or indoor loop	Tiny and tunable	Low efficiency and narrow bandwidth, close to people and noise
Flagpole vertical	A normal object that hides a vertical	A good ground system is hard to hide
Thin wire to a tree	Fine wire is almost invisible	Low and tree-dependent; wire moves in wind; usually needs a tuner
Portable antenna on a stand	Only up when in use	Time to set up each time

What to expect

Indoor and hidden antennas typically lose several dB relative to a clean outdoor dipole, and sometimes much more. That can be the difference between a solid contact and no contact. To make the most of it:

• Get some height and distance from clutter. Move it outward and up, away from wiring, pipes and big metal.
• Choose the mode. Low power digital modes such as FT8 work well with compromise antennas because they decode weak signals; see FT8 and FT4.
• Keep the radio side clean. An indoor antenna sits close to home electronics: expect noise on receive, and watch for interference on the transmit side; see RFI and EMI overview.
• Stay safe. Antennas in a loft or by a window are close to people, so keep power low and keep them out of reach; see RF exposure.

Rules, covenants and the law

In the US, the FCC's PRB-1 limited preemption tells state and local governments to reasonably accommodate amateur antennas. It is aimed at government regulation, not at private deed restrictions or a lease, which are a contract between you and the other party. Details change and every situation is different, so neither this article nor PRB-1 is legal advice. Read your documents, ask the board or landlord, and see Antenna restrictions and PRB-1.

Related

• Antenna restrictions and PRB-1Zoning, covenants and your rights.
• Small magnetic loopsTiny, high-Q antennas with a narrow bandwidth.
• Loaded and short antennasTrading size against efficiency.
• End-fed half-wave antennasA half-wave fed through a high-impedance transformer.
• Long wires and random wiresSimple wire with a tuner: benefits and traps.
• Portable and field antennasLight, quick designs for SOTA, POTA and camping.