Selecting a Marine VHF Radio

WELgeE TO OUR VHF RADIO BUYING GUIDE

Wed like to share some of the information weve accumulated about Marine Navigation and gemunication Units. Whether youre looking for a VHF Radio, Fishfinder or GPS Chartplotter, now or in the future, you may find something in this guide useful. The guide may help to answer some of the questions you have or you might find a tip here that's helpful to assist you with your decision.

Before we start, it is important to note that we are not experts in the field of marine radios, electronics or navigation. The true experts are the engineers and technicians that work so hard to design and manufacture these modern, innovative products. The guide is intended to be helpful and informative but is not intended to replace the manufacturers technical information or their regemendations for use.


VHF RADIOS

What they are:
A VHF radio is a two-way gemunication device with a range of between 5 and 50 miles. On inland waters the VHF radio is usually the quickest and simplest way to contact the U.S. Coast Guard, other boaters, a tow or other rescue service, bridge tenders and weather broadcasts. Other than personal flotation devices, the VHF radio is possibly the single most important safety item in your boat. Your VHF radio allows you to gemunicate directly with other boaters. If you need assistance on the water, it is other boaters that you will depend on.

Handheld vs. Fixed Mount:
A handheld unit is usually battery operated and can be especially useful if there is a power outage on your boat. Conversely, a fixed mount unit runs off the power source in the boat and therefore never needs recharging. In most instances, the transmit distance of a fixed mount will exceed that of the handheld unit. There are a great number of factors that influence this difference. Transmit power, antenna height and length are a few of the differences affecting performance. The handheld unit does make a fine backup to your fixed mount unit. Many offer up to 5 watts of transmit power. Emergency strobe lights, advanced receive capabilities for FM music stations, AM broadcast band and Aeronautical band are a few of the new features being offered in handheld VHF. You can decide for yourself how useful some of these might or might not be. Handheld units are also starting to offer DSC technology. An explanation of DSC is provided further below.

How VHF radios work:
Fixed mount VHF radios are limited by law to 25 watts of power while transmitting. They generally have an option to transmit on 1 watt of power for short range conversations. These 1 watt conversations are less likely to interfere with the conversations of others who are using the same channel. Remember, we said they are able to transmit between 5 and 50 miles at full power. Thats a lot of overlapping conversations if there are two hundred boats using the same channel in the same general area.

VHF radios receive and transmit line-of-sight signals. This being the case, buildings and other land masses or the curvature of the earth limit the unit and can also block the VHF signals. Your VHF radio can only hear the strongest signal it receives. Therefore, whenever there is more than one conversation, taking place at the same time, you will only hear the strongest signal.

Reception and Range:
Now that we already know that the VHF radio is limited to 25 watts, what can we do to insure that we get the best reception and range. Antenna placement is the single most important factor to consider. Your antenna should be mounted as high as possible on your boat. Consider other factors you may have to contend with like low bridges and the like. You may even want to make sure it is away from small children. Use your imagination when selecting the spot but make sure it is as high as you can get it to optimize the broadcast and reception of the unit. If it will be mounted in a remote location such as the mast of a sailboat, use only low-loss coax cable with a large diameter.

Features:
Different radios offer different options for operation such as channel selection using a keypad or a rotary knob, controls in the microphone and so forth. They also vary in features. A variety of options exist for scanning. There is an all-channel scan that allows all channels to be scanned at the same time. We cant imagine using that feature on a crowded bay but it might be useful further out in the ocean, where theres fewer boats around. A priority scan is available on some radios that overrides other radio traffic and places a priority on Channel 16 messages. Almost all offer programmable scanning features where you decide which channels to scan. Another feature, useful with many boaters, is the ability to add a second station by means of a full function remote microphone. Its also a good time to decide if you need a PA system or a hailer output.

Other Features:
A brand new technology has emerged in VHF radio. Its called Digital Selective Calling (DSC). DSC allows the VHF radio to send a digitally encoded distress alert including a special ID number and the lat/lon of the vessel provided its interfaced with a GPS. You can imagine the potential benefit to a boater in distress. Your message will be sent to other DSC equipped boaters and rescue facilities. After your message is sent, the radio automatically switches to Channel 16 where you can make additional emergency gemunications. The program is expected to be fully operational by the end of 2006. Certain pilot areas may already be operational. Before you can use DSC you are required to obtain a Maritime Mobile Service Identity number (MMSI). The information you provide on the application is stored in the Coast Guard national distress database to be used in event of an emergency. There are other uses for DSC equipped radios that manufacturers are in various stages of implementing. Making a selective call to a specified vessel, plotting another vessels position and other data transmission capabilities. Additional MMSI information can be found at the U.S. Coast Guard Website.

Water Resistance:
This is a term that means different things to different folks. For now, well say that standards vary with respect to how waterproof you can expect your VHF to be. The units that will perform best under severe conditions are often those advertised as having sealed cases and being submersible. Even if a manufacturer claims that his unit is submersible you shouldnt plan on leaving it underwater for an extended period of time. You should always plan to locate your radio in an area where it will have the least amount of exposure to wet elements and still be accessible. Your goal should be to have it in working order for when you need it and not to test the manufacturers claims of water resistance. By the way, it doesnt hurt to have a handheld in reserve.

Selection of a Unit:
Much of the selection process involves your intended use. Whether you are a recreational boater or a seasoned gemercial fisherman you must first decide what you need from your radio. This will establish handheld or fixed mount and a few of the features you need. Then, look at the features on several units and decide on the features you want. Once you know the features you need and those that you want, select a brand that has a reputation for producing reliable, durable, quality products.

Price:
Whether you buy from us or from another vendor, dont sacrifice your safety or the safety of your passengers to save a few dollars. While guests are aboard your vessel they are your responsibility. Your top quality VHF radio will be priceless the first time its used in an emergency.

MARINE_WIZ