How Do I Know My VHF Radio is Working?
VHF radios are essential safety equipment on any powerboat, and skipper should know its operation and its features. Digital Selective Calling (DSC), linked with your GPS unit so your latitude/longitude data are broadcasted, would be an ideal setup.
Remember, VHF radio isn’t private telephone: anyone tuned in can hear you. Perform regular radio checks to make sure your set is functioning efficiently.
Check the Antenna
VHF radios are essential tools in boaters’ safety gear. From communicating with other vessels to reporting an emergency situation to authorities, these radios have many uses on board a boat. But their effectiveness ultimately relies on its antenna. Improper installation can interfere with transmissions, reduce its range, or even render the radio unusable altogether.
One of the key features of a VHF antenna is its height. Radio waves travel in straight lines and gradually lose power with distance; for communication to take place effectively between antennas, both antennas must have clear lines of sight between themselves; this is why VHF antennas should be mounted on boats’ highest points – longer antennas “see” more of what lies beyond their immediate surroundings, increasing your radio’s range.
Along with considering the height and orientation of your antenna, it is also crucial that you pay close attention to its gain. Antenna gains are measured in decibels (dB), with higher numbers signifying improved performance. An increase of 3 dB doubles signal strength; six-dB gains can extend range fourfold.
Coax cables should also be carefully considered when selecting your antenna, as longer cables result in more dB loss and could significantly impact radio performance. Utilizing either an RG-8X or RG-213 coax will minimize losses while increasing efficiency for VHF antennas.
As Catoe points out, antennas radiate signals from their base upward. Many consumers make the mistake of thinking they are receiving strong signals when in fact only receiving very limited signal strength from its tip.
If your VHF radio appears to have difficulty transmitting, using a multimeter to test both its antenna and connections could help diagnose any problems. Remember though that multimeters measure DC resistance rather than RFI impedance; so if it cannot match perfectly (50ohms on its display meter reading), that indicates issues with either its cable or antenna may be at play.
Check the Power
VHF radios are intended for short range communications (up to 20 miles in most cases), such as distress and safety calls or communicating with Coast Guard stations. To extend your range, a satellite telephone or an MF/HF marine radiotelephone would often be necessary.
First and foremost, make sure your radio transmitter is functioning correctly and transmitting with sufficient power. To do this, check the amp meter when pressing down on your microphone transmit button – when transmitting at higher power levels you should see 4-5 watts on this meter; while when transmitting on low power it should show close to one watt on this gauge.
Make sure that your transmitter is set in the appropriate mode, and take note that certain radios have limited peak envelope power (PEP) depending on their license class – General and Extra Class licensees have up to 1500W of PEP available on VHF bands while Technician class licensees have 200W available for HF bands.
Test the sensitivity of your radio by connecting it to a portable radio and tuning to channel 16. When testing on VHF channels, call and listen for replies on channel 16 until hearing an audible reply indicating a working channel and listening for any reply messages from it – if this signal from portable is loud and clear then your VHF radio should work fine!
Most modern marine VHF radios feature multiple usable channels, and most vessels should monitor the national safety, calling, and distress channel (16) continuously. Furthermore, it would be wise to regularly scan both hailing channels (9 and 13).
Many modern VHF radios feature advanced features like dual watch and tri-watch scanning modes that automatically switch between two or three monitored channels in succession. You can select priority and normal scanning options using soft key labels on your radio. Furthermore, you can configure it to display GPS status on-screen as well as setting backlighting using another soft key label.
Check the Squelch
VHF radio squelches are designed to block out static from reaching its speakers, and setting yours correctly can improve safety, lower power usage and enhance overall radio experience.
VHF radios come in various models, from affordable handheld units to expensive fixed-mount systems. Handheld models offer limited power and range (up to five or six watts depending on atmospheric conditions and antenna height) while fixed-mount VHFs may produce up to 25 watts with up to twenty miles or more range (depending on environmental factors).
Marine radios all perform the same basic function: communication among boaters on designated channels, sharing weather reports and information, alerting emergency response services, etc. Modern VHFs offer over 25 usable channels with options to view multiple simultaneously while setting personal channel preferences. Many models also offer digital selective calling capability (DSC), which enables sending encoded distress calls directly to vessels equipped with DSC capability.
Before using a VHF radio for transmissions, ensure it is turned on and tuned to the appropriate channel. Before speaking out on any channel, scan through other boats’ transmissions in order to identify where you need to transmit. When it’s time to speak out on one, position the microphone a couple inches from your mouth on an angle so as not to interfere with other transmissions and speak slowly and clearly so your message can be understood by all listeners.
Foul language and false distress calls are illegal, so always end any conversation by introducing your vessel name and making a statement like “over” or “out.” In case of emergency contact with the Coast Guard, dial 16 at full power with Channel 16 set as the frequency. Declare “Mayday!” or “Abandon Ship!” before beginning your call to notify them that assistance is required.
Conducting periodic VHF radio checks can keep it operating efficiently and prevent potential problems before they arise. By taking the time to follow these simple steps, your next sailing voyage will have an dependable communication system!
Check the Volume
VHF radios remain essential pieces of equipment for sailors onboard despite all the excitement about cellphones, providing direct communication between boats. In an emergency it also connects you with Coast Guard Rescue 21 via Digital Selective Calling (DSC), significantly speeding up response time.
For emergencies, your VHF needs to work as intended. Therefore, regular testing should be conducted in order to make sure it stands up. An ideal time and place for this is before leaving the dock; though professional installation checks may also help, there are simple things you can do on your own to make sure your radio is fully operational for this season.
One of the most frequent errors involves forgetting to set their radio on the correct channel mode prior to making or receiving contact. This mistake could prove costly during an emergency as all channels are closely monitored by both Coast Guard and other authorities.
An easily correctable error is failing to keep the squelch turned down enough. A casualty in distress might only have access to a handheld VHF radio which will only just be audible above noise; too high of a squelch setting could reject weak broadcasts due to rejection noise; keep it turned down until there’s no white noise from speaker speaker output.
Test this by listening to all ship-to-ship or working channels as well as the Maritime Aids to Navigation system channel (16). Keep an ear out for any broadcasts, then gradually decrease your squelch until no transmissions can be heard.
If you don’t own a VHF test device, Shakespeare’s ART-3 radio/antenna tester ($125) could be useful. This palm-sized unit can be connected directly between radio and antenna to act like a stethoscope while monitoring frequency, power output, and signal strength.
If you plan to transmit, be mindful that VHF channels are open and any individual can listen in on any conversations on them, especially in emergency situations. Therefore it’s wise to limit conversations to essential topics without using foul language or false distress signals that might land you in hot water with authorities.
