HF installation in boats and vessels – Complete guide for marine radio

How to install HF/SSB station, antenna, and grounding for safe communication at sea

A marine HF station is used for communication with coast radio stations and other vessels. The equipment must be approved and meet applicable requirements. HF stations may not be used for amateur radio, and amateur radio stations may not be used for contact with coast radio stations or vessels.

To transmit via a marine HF/SSB station, a radiotelephony certificate is required, which is obtained after training and examination at Stockholm Radio. This certificate is not valid for amateur radio.

Connecting the antenna tuner

Connect with coaxial cable, for example, RG-58 (up to 30 m) or RG-213 for higher strength. Create an RF choke by winding the coax 10–15 turns (100–150 mm diameter) at both ends. If necessary, use ferrite cores to reduce HF interference.

Antenna

The most common is a stripped stay as an antenna element, 10–18 m long. The tuner is placed at the beginning of the antenna. It is important that the antenna cable hangs freely and does not rest against grounded objects.

Grounding

Grounding is crucial for good function. Connect the antenna tuner's ground screw to the sea via sintered bronze plates below the waterline. Use thick conductors (6–20 mm²) or copper tape for low impedance.

Radio station

HF stations require 12 V and approx. 20 A when transmitting. Connect directly to the battery with thick cables. Avoid using the hull as a negative conductor. Check for corrosion and keep the electrical system floating.

Problems and solutions

Short antenna and poor ground can cause interference. Solve by alternative grounding, ferrite cores, or reduced power. A backup antenna can be a telescopic fishing rod with cable.

HF radio at sea

HF radio provides safety and communication on the open sea. The emergency frequency 2182 kHz provides 100–300 km range. Possibility to receive weather faxes, listen to broadcast radio, and keep in touch with other ocean sailors.