Marine Communications
VHF radio stands for Very High Frequency. This is the band of frequencies between HF and UHF, of High Frequency and Ultra High Frequency. VHF radio operates around 150 Mega Hertz. Typically you can count on 10 miles or more of range from a 25 W fixed mount VHF.
Performance is directly related to the antenna. Like everything else, it is the sensor. Of course other factors affect performance also, such as the receivers’ sensitivity and the overall quality.
I sell Icom VHF products, but the technology is quite mature and the era of “good enough” VHF is already here. Reliability and features drive the buying decision.Features include built in hailer, fog horn, remote microphones and DSC or Digital Selective Calling. DSC is a system where the VHF can send an AUTO MAYDAY.
By hooking your GPS to the VHF, the radio is enabled to press and hold the MayDay button and send you lat and long with a May Day message. DSC also allows for private calling using MMSI. If you have an MMSI number, your auto mayday will contain your vessel name.Single Side Band radios are used for long range communications. By transmitting only the sideband at a high level, these radios bounce the signal off of the sky and can literally talk around the globe, depending on the position of the sun.
Single Sideband operates in the HF spectrum. It requires a large ground plane to work, usually consisting of all the metal on the boat + additional copper strapping, often lain into the hull.
A scratch installation of a SSB radio is quite difficult because of the ground plane requirement. Also, the antenna needs to be long, so sail boaters use their back stay, insulated as an antenna.
Cell phones work near shore, but reception can be spotty, kind of like land, but worse. Once you travel far from the cell towers, reception becomes impossible. A cell phone will not work without service, so as an emergency radio, they are almost useless.
Cell service boosters can help with cell reception, but it is a losing battle if you cruise long distances.
