VHF RADIO COURSE (NEMO) Flashcards
Identify parts 1-9
Squelch button?
Squelch mode: determines how open the signal is and how much background noise is picked up. Used to find clearest signal.
Scan button?
ONE PRESS: Dual Watch Mode, flips back and forth between the priority channel (16) and the current user defined channel.
TWO PRESSES: Memory Scan mode, scans through user chosen memory channels.
To select channels for Memory Scan mode, PRESS & HOLD SCAN BUTTON until a tone is played.
Transmit Power button?
Changes the strength of the signals being sent or received.
Note: Some channels can only be accessed on low power.
Priority channel button?
Used to either clear out of the current menu/function, change the current channel directly to the priority channel (16), or select the current channel to transmit/receive signals (Dual Scan mode).
ONE PRESS: clears menu or switches to priority channel.
PRESS & HOLD on channel other than 16: plays a tone and the current channel will be selected.
What are the 3 types of communication channels?
- Simplex Channels
- Duplex Channels
- Semi-duplex Channels
What is a simplex channel?
- Uses the same frequency to transmit and receive, so you can only transmit or receive at any one time.
- Ch. 16 is a simplex channel as well as other commonly used intership channels.
What is a duplex channel?
- Normal two-way conversations.
- Used in only some VHF channels.
What is a semi-duplex channel?
- Similar to a simplex channel wherein you can only transmit or receive at any one time.
What 3-5 steps are taken in making contact with other vessels or stations?
- ESTABLISHING CONTACT: Identify yourself using VESSEL NAME and CALL SIGN.
- WHEN MAKING CONTACT: Initially give the NAME OF VESSEL you are calling followed by YOUR VESSSEL’S NAME at least once. You may repeat each name up to 3 times but it’s not necessary.
E.g. “X, X this is Y, Y over”
- If you’ve made a call on Ch. 16 you will need to move to a working channel to continue the conversation. The called vessel/station should control the conversation so they choose the working channel, although the calling vessel/station may sometimes suggest a working channel.
- If no response is heard, check that your radio is set up correctly, then wait TWO MINUTES before calling again. After 3 failed attempts, wait THREE minutes before trying again.
Distress calling consists of which 3 steps?
Distress Call: Once you have sent your distress alert, leave a short pause of a few seconds before making your distress call and message. You do not need to wait for the alert to be acknowledged before making the call. The call and message are both transmitted on channel 16. At this point DSC radios will have automatically switched to channel 16 on high power. This call gives everybody warning that a distress message is to follow, and gives them time to prepare to write the details down. The distress message follows immediately after the call.
Distress Message: The message should be broadcast immediately after the call, without releasing the transmit button in between. To make sure everything is included, there is a specific order in which we should deliver our message. It is common to use the mnemonic word ‘MIPDANIO’ to help us remember this order.
M-I-P: The first part of a distress message is a shorter version of the distress call to ensure that your details can be recorded. Then you tell the authorities where you are, you need to give the SAR authorities the best chance of finding you by giving them accurate details. You can specify your location by latitude and longitude, or range and bearing from a known or charted object. You also need to give your location as the direction from the object, the name of the object and your distance from it.
D-A-N: Give a brief, concise description of the problem. There is no need to explain how things happened as this only wastes valuable time. Always follow the problem with ‘I require immediate assistance’. This explains that you need help quickly. Also, give the number of people on board.
I-O: This part of the message gives you the chance to include anything else that could be useful to the rescuer. It can include what the boat looks like, or your intentions such as abandoning the life raft. Finish the message with ‘Over’ as you are inviting a reply to your message.
What does the mnemonic MIPDANIO stand for?
How is an ‘urgency’ situation defined?
The definition of an urgency situation is ‘when the calling station has a very urgent message to transmit concerning the safety of a ship, aircraft or other vehicle, or the safety of a person’.
Urgency calling consists of which 3 steps?
PAN PAN: An urgency call is used when there is an urgent message concerning the safety of a mobile unit (e.g. a ship) or a person. This can be a request for urgent medical advice for a crew member. An urgency call needs directing to either all ships, or sometimes an individual station or Coast Guard. The words ‘PAN PAN’ indicates an urgency call, just as ‘MAYDAY’ indicates distress.
Give an example of an urgency call from a vessel or ship station.
Give an example of an urgency call from a coastal station.
VIEW: Emergency Radio Call Procedures
