VHF Radio Operation, Controls and Channel Usage
The controls you will actually touch
The rotary knob is on/off and volume. The squelch is set just past the point where background hiss stops, so weak distant signals still open the receiver. The channel selector and keypad choose channels and menu items; the high/low power key switches between 25 W and 1 W; the PTT is pressed fully before you speak and released when you finish. Dual watch monitors Ch 16 plus one working channel; scan steps through a memory list. The red distress button sits under a cover on DSC sets and is never pressed as a test.
Channel plan essentials
Ch 16 is distress, safety and calling. Ch 70 is DSC only - no voice, ever. Ch 13 is intership navigation safety (bridge-to-bridge); Ch 06 intership safety; Ch 72 intership for non-commercial craft; Ch 77 for intership and ship-to-shore working in many areas; Ch 80 and M1/M2 (Ch 37) for marinas and yacht clubs; Ch 00 for HM Coastguard in the UK; Ch 67 for small craft safety in the UK; Ch 15 and 17 for on-board communications. Port operations, VTS and harbour authorities have their own allocated channels, printed in almanacs and on charts.
Voice technique
Listen before transmitting. Press PTT, pause a beat, then speak slowly about 10 cm from the microphone in a normal voice. Identify with the vessel name and callsign. Use standard words: "over" to invite a reply, "out" to close, "roger" for received, "say again" for repetition, "standby" for wait. Spell names with the phonetic alphabet and say digits individually - "niner" for nine, "tree" for three.
Worked example
You want a berth in a marina that lists Ch 80 as its working channel. Do not call on Ch 80 out of the blue. Call on Ch 16 first - "Marina X, Marina X, this is Sea Breeze, Sea Breeze, request berthing instructions, over" - then switch to the channel the marina nominates, usually Ch 80, and continue there on low power. Reasoning: Ch 16 is a calling channel only; the conversation must move off it so the frequency stays free for distress traffic.
Traps
- Chatting to a friend on Ch 16 - an immediate fail in the practical exam.
- Saying "over and out"; the two contradict each other.
- Leaving the squelch wide open so you hear constant noise.
- Transmitting at 25 W from inside a marina, blocking everyone for miles.