A recent U.S. Coast Guard rescue operation here in southeastern Connecticut in which a distress call on the VHF radio resulted in a good Samaritan mariner recovering four passengers from a capsized vessel is a great reminder of the importance of a functioning marine radio.
The quick story: a boat in distress put out a call to the USCG on the VHF, which was being monitored by a good Samaritan who responded to the sinking boat and took the endangered crew aboard his boat until the Coasties arrived. The linchpin in this great story: a functioning VHF radio.
For many mariners – especially weekend boaters or casual fisherman who don’t use their vessel every day – the VHF Radio is infrequently used; you’d be surprised at the number of boats we encounter without one at
all. If you do have a VHF, it’s only a benefit if it’s operating correctly. Which leads to the topic of this post: how can you determine whether your VHF radio is functioning as intended. Here are some tests you can conduct yourself.
Transmission Tests
What is the best way to make sure you have a functioning VHF? Test it. There are a variety of ways to determine whether it’s transmitting.
- The first is to make an on-the-air radio check by asking for confirmation of message received from another boat or shore station that is a reasonable distance away. When doing this, you should avoid using Channel 16, which is for hailing purposes only.
- If this isn’t possible, switch your radio to low power (1 watt) and monitor yourself on a handheld VHF. You’ll probably need to turn the volume down and keep the handheld away from your boats primary radio and antenna to minimize proximity feedback squeal. Another option in this method is to have a crew member take your portable down the dock for an on-the-air radio test.
- A third transmission test is to watch your boat’s amp meter when depressing the radio microphone transmit button. When transmitting on high power (25 watts), you should see about 4 to 5 amps registered on the meter; on low power is should be close to 1 amp.
Reception Check
In most communications scenarios, the key to success is a two-way exchange of information. It is no different with Marine VHF radios. No matter how well your radio is transmitting, if you can’t hear a station transmitting back you don’t have communications. Here are two tests to check your radio’s “hearing ability.”
Local Weather Test – Use a local weather channel to verify that you are hearing the broadcast clearly and without distortion. If you can, switch to a weaker, more distant weather channel to test your radio receiver’s ability to hear weaker signals. For further reception diagnostics, remove the antenna cable connector from the back of your radio while monitoring local weather. Then insert the tip of a small screwdriver or paper clip into the center contact of the radio’s antenna jack. If you can still hear the weather broadcast, your radio most likely has good reception.
Sea Tow Automated Radio Checks – Sea Tow operates a network of automated radio-check stations in many parts of the country as a public service. You can check your VHF radio by calling the station in your area. When you transmit on its channel, you will hear a recorded response and then hear a playback of your voice verifying that your radio is transmitting, modulating and receiving. Check the Sea Tow website to if this service is offered in your area and on which channel it operates.
Shakespeare Radio-Check Meter
Finally, if you require more consistent feedback on your VHF radios transmission and reception performance, install a Shakespeare Radio-Check Meter. Their ART-3 Antenna Radio Tester is a palm-sized monitor that easily connects between your radio and antenna. It will give you a readout on your radio’s power output, the health of your antenna and cable, and evaluate your reception as well. It can also be permanently mounted next to your radio to provide a radio check every time you transmit. What’s more, Shakespeare also has a very nice video on trouble-shooting radio and antenna problems.
Pro Tip
A common error is miss-setting the channel mode. VHF radios operate on three different channel groups: U.S., Canada or International. An incorrect channel-mode setting might result in the inability to communicate on some channels. An icon on your radio’s screen indicates which mode your radio is operating on.
If you have any questions about the health of your VHF radio, or any other Marine Electronics or Electrical issues, please contact us for a complimentary consultation.