How long must a transmission length be?

• A. 10 seconds
• B. 20 seconds
• C. 30 seconds
• D. 60 seconds

Answer: (B)

In radio practice, the airtime you take on a shared channel should be brief enough to keep the channel available for others. A practical rule of thumb is to keep a single transmission around twenty seconds. That length lets you include essential information like your call sign and location and still leaves time for others to respond or call you back. If you have more to say, break it into shorter, successive transmissions rather than a long one, so the net remains open for others to participate. Longer transmissions—thirty, sixty seconds or more—tend to tie up the channel and reduce opportunities for others to join in, which is why twenty seconds is considered the best upper limit here. Shorter transmissions can be too brief to convey what you need, but they’re easier on the shared link and help maintain efficient, fair access for everyone.