🔍 Key Concepts

• ITU HF channel numbering convention (four-digit numbers like 1212, 1225, etc.) • Difference between band designation (e.g., 12 MHz band, 16 MHz band, MF band) and individual channels within that band • How the first two digits vs last two digits in an ITU HF channel number are typically used

💭 Think About

• Look at the four digits in 1212. What could the first two digits logically represent in terms of HF bands used for maritime communications? • Then think about the last two digits: what might they indicate – the band itself, or the specific channel within that band? • Eliminate any options that mix up MF vs HF or that describe a channel number that does not match the given 1212 pattern.

✅ Before You Answer

• Verify which frequency range is called MF (medium frequency) vs HF (high frequency) in ITU allocations. • Check how ITU designations like 1212 usually map: band ID vs channel sequence within that band. • Confirm whether calling something “Ch‑1216 in the MF band” makes sense if the question clearly states it is a high frequency (HF) ITU channel.