🔍 Key Concepts

• Auto-alarm signal pattern used in radiotelegraphy for distress (older GMDSS-era knowledge) • Difference between number of dashes, length of each dash, and total duration limit • How spacing between dashes is specified in seconds and how that affects total time

💭 Think About

• First, recall from your studies how many dashes make up the traditional auto-alarm signal used to trigger automatic receivers. Is it three, four, or five? • Think about whether the auto-alarm specification includes a maximum total duration for the whole combination of dashes plus spaces, and roughly what that limit is. • Compare the dash lengths and spacing in each choice: which option matches the idea of a short, distinctive pattern that will reliably trigger auto-alarm equipment without being too long?

✅ Before You Answer

• Verify the correct number of dashes required in the official auto-alarm signal definition. • Check whether the maximum total combination time (dashes + spaces) is part of the official standard and if it matches any choice. • Confirm that the dash duration range and space duration range in the choice you’re considering are both within the officially prescribed limits.