🔍 Key Concepts

• VHF marine radio channel spacing used in most international channels • Difference between channel spacing (distance between center frequencies) and bandwidth of a single transmission • How modern marine VHF channels are arranged in the 156–162 MHz band

💭 Think About

• Think about how many separate voice channels need to fit into the limited VHF marine band. Would wider or narrower spacing allow more channels? • Recall what spacing is typically used for standard international simplex/duplex marine channels like Channel 16 (156.800 MHz). • Consider typical commercial communications radio systems: what spacing is commonly used for analog FM channels in the VHF band?

✅ Before You Answer

• Verify what channel spacing actually means (it’s not the transmit power or modulation type). • Mentally place Channel 16 at 156.800 MHz and think about where the next channels sit in frequency – how far apart are their center frequencies? • Make sure the spacing you pick seems realistic for fitting many channels into a relatively narrow marine VHF band.