What is VHF?

What is VHF?
“VHF” stand for Very High Frequency - 156 to 162Mhz; VHF is a radio that can transmit as well as receive. Your transmitted voice is frequency modulated (FM) and another receiver tuned to the same channel can pick it up.


What does power rating signify?
Fixed mount VHF radios transmit at a selected power level of 25W or 1W. Portable VHF radios are 5W and 1W. Lower power is used around the marina. 
Signals amplified with 1W, 5W, 7W, and 25W power travel the same distance.  A stronger signal will overcome another radio's weaker signal and "takeover" the channel. However, if the channel is clear, as it is most of the time, the radio transmit power does not determine the range of the radio.


What determines the range of your VHF radio?
VHF communication is limited to direct line-of-sight and the effective range is mostly determined by the height and sensitivity of your antenna system.
The distance to the horizon depends upon the antenna height above the water. VHF radio waves travel approximately via line of sight.


Can you use a VHF radio on land?
Yes, a license must be filed with the FCC.  See the Owners Manual included with our handheld VHFs for an application that includes details on how to submit the application.


Why buy a VHF instead of using your cell phone?

  • A VHF radio is a safety device designed for specific marine risks, the most commonly installed electronics by boatbuilders, and the most commonly used safety device by experienced boaters.  In an emergency, would you trust a cell phone?
  • Anybody with a VHF radio on the same working channel can hear you talking, whereas a cell phone is limited to a single person or contact. CH16 is a recognized calling channel that many boaters on the water monitor
  • Direct boat-to-boat or bridge tender communications via cell phone is not possible.
  • Cell phones range is restricted and can be affected by weather
  • Cell phones lack safety features such as weather alerts, DSC…
  • Cell phones are also not water resistant, whereas all Navico VHF radios have JIS-7 rating.


What does JIS-7 mean?
 JIS = Japan Industrial Standard; 7 is the grade, 7 = submersible to 3 feet water depth for up to 30 minutes


What basic weather monitoring/alert functionality is provided?
All fixed mount and handheld radios include NOAA Tone Weather alert.


What is SAME?
SAME stands for Specific Area Message Encoding.
This is a system established by the National Weather Service (NWS) to provide County by County weather warnings. Using SAME localizes the warning alert  to your area of interest.
You set up SAME by entering the County 6 digit code in the menu screen and select ON. County code is found at www.mws.noaa.gov/nwr/index.htm.
You can select to simultaneously monitor up to 4 Counties in the set up screen.
You can select between a simple TONE alert or a County specific alert.


What is DSC?
Digital Selective Calling - There are several types of DSC calls; an individual DSC call allows you to call a specific vessel (similar to dialing a phone number).  Once the DSC system has established the connection, the voice communication is carried out just like any other VHF call. DSC-DISTRESS calls (which are monitored by some countries) allow you to automatically broadcast vital information such as your vessel ID and GPS position in case of an emergency.


What is Track-Your-Buddy™?
Select models utilize DSC-VHF and GPS to monitor the position of up to 3 of your buddies at 15, 30 or 60 minute intervals. You Buddy's radio is polled and it's position gathered. The data is displayed on your VHF’s LCD screen, and can even be relayed via NMEA-0183 to your chartplotter, where it can be overlaid on your map. The polled radio has a choice of replying back automatically, manually or blocking the request if privacy is a concern.


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