Can you use a VHF aerial for AIS?

VHF antennas can work on AIS, yet the frequency of 162 MHz they will be operating at, is at the high end of the operable bandwidth of the antenna, where performance is not ideal. Many of the AIS transmit/receive units are also coming with splitters now, to utilize the same antenna as your VHF radio.

Does AIS require a special antenna?

AIS communicates with other vessels over VHF and therefore requires a VHF antenna; however, in some cases using a splitter with an existing antenna is a great alternative to installing another dedicated antenna.

What antenna does AIS use?

Antenna type: The type of VHF antenna you use with your AIS system can also have a big impact on AIS range. Most VHF antennas are optimally tuned around 155-156 MHz but AIS uses frequencies around 162 MHz. In some cases, a good VHF antenna might be substantially less tuned at even close adjacent frequencies.

Do I need VHF with AIS?

For AIS Transmit and Receive, you need two pieces, a VHF Radio with DSC built-in plus an AIS Transponder.

What is VHF with AIS?

The Automatic Identification System is a digital VHF radio-based transponder system that can prevent collisions, and can protect your boat from being run down by a huge, fast moving ship. It's like digital radar with precise position information.

Selecting Antenna AIS Class A or B - Digital Antenna, Inc

Why do some boats have 2 VHF antennas?

The advantages of the dual antenna

Not only does the installation of a second antenna give better readability to the AIS signal, but it can also serve as an emergency antenna for VHF. Just allow enough length behind the unit to disconnect the antenna from the AIS and connect it to the VHF.

Where do you mount AIS antenna?

Typically this antenna is mounted at the top of a mast, radar arch, flybridge, or another high point onboard where it has the greatest range and is more likely to receive weak signals.

Does a VHF antenna need to be vertical?

No matter how tempting it might be to angle your boat's VHF antenna for aesthetic purposes (like matching the angle of fishing rods), don't do it. Sure, it looks sleeker to have them angled, but they're designed to be positioned upright for a reason.

How high does a VHF antenna need to be?

Marine VHF Antenna Height and Strength

A 3- to 4-foot antenna that's 3 dB is generally recommended for boats under 24 feet. Larger vessels can opt for 12- to 18-foot, 7 to 8 dB antennas. “As a general rule, antenna height should be less than half the length of the boat,” Catoe says.

Do I need a VHF antenna?

Generally, our bowtie antennas can receive high-VHF broadcasts. However, if the VHF signals in your area are weak or are transmitting from a tower more than 20 miles from your home, a longer-range VHF antenna may be necessary to ensure reception of all your available local stations.

How long does a VHF antenna last?

They typically last for five to ten years. Antenna height, more than anything else, determines the distance you will be able to transmit radio signals. The higher an antenna is mounted on a ship, the further it can "see" over the horizon. Antenna gain is the next most important feature.

What is the maximum range of AIS?

The AIS signals have a horizontal range of about 40 nautical miles (74 km), meaning that AIS traffic information is only available around coastal zones or in a ship-to-ship zone. AIS communication takes place using two VHF frequencies, 161.975 MHz and 162.025 MHz, using a bandwidth of 25 kHz.

How far apart do VHF antennas need to be?

The easy answer is that you should maintain a minimum mounting distance of at least 1/4 wavelength apart for the lowest frequency antenna within the same horizontal plane. For VHF antennas, that translates to roughly 19 inches. This is the rule we use when installing omni antennas on a the trunk of a vehicle.

What VHF antenna is required for AIS receiver and transponder?

Which VHF channels or frequencies are used with AIS? AIS transponders and receivers use two VHF radio frequencies: 161.975 MHz (AIS1, or channel 87B) and 162.025 MHz (AIS2, or channel 88B).

What is the difference between AIS transponder and transceiver?

An AIS transceiver uses VHF radio and GPS technology to communicate with other nearby ships. An AIS transponder determines its own position, speed and course using a built in GPS receiver.

Do I need AIS on my yacht?

The answer for most recreational boaters is maybe. No, you don't have to have AIS, just like most boaters aren't required to have radar or an EPIRB. Heck, many recreational boaters ply inland lakes, bays, and rivers in areas where commercial traffic isn't too much of an issue in the first place.

Does VHF antenna length matter?

The length of your antenna determines how good it is at handling certain frequencies; according to experts, there's a sweet spot that gives you the best signal. If you use an antenna that's too long or too short, your signal might cut in and out at times.

How far will VHF transmit?

A typical VHF station operates at about 100,000 watts and has a coverage radius range of about 60 miles.

What is the best VHF aerial?

What is inside a VHF antenna?

There inner electrical element (the part that radiates and receives signals) of VHF antennas is generally made of one of three types of materials: coaxial cable, copper or brass. While all provide acceptable performance, better antennas use brass or copper for optimum performance and durability.

Why do antennas need to be grounded?

Grounding will eliminate static electricity, as well as protect against energy to the mast if the antenna comes in contact with live electrical wires. Outdoor masts should be grounded with Grounding Conductors (see F in diagram) to the building's Power Service Grounding Electrode System (see E) at a permitted location.

Can two antennas interfere with each other?

Isolating antennas at different frequencies

Antennas that operate on different frequencies should be placed so that they will not interfere with each other. In antenna terms, they need to be electrically isolated from each other.

Can I connect my GPS to the AIS?

Our very popular AMEC CAMINO-101 Class B AIS transponder can now either use its internal GPS system coupled with the AMEC external antenna or it now supports using an external GPS device connected through the inbound NMEA port.

What are the problems caused by installation of AIS?

Limitations of AIS

The position received on the AIS display might not be referenced to the WGS 84 datum. Over-reliance on the AIS can cause complacency on the part of the OOW. Users must be aware that erroneous information might be transmitted by the AIS from another ship. Not all ships are fitted with AIS.