Why do boats have 2 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.

How long should my marine antenna be?

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.

How can I boost my marine radio reception?

Increasing the antenna height can also increase distance, so mount your antenna as high as possible, such as on top of your boat’s hardtop or radar arch. You can also get greater range with a longer antenna — it has a larger radiating element. Additionally, keep in mind that not all VHF radios are created equally.

Are VHF antennas interchangeable?

Customers have asked us if it’s necessary to match the antenna gain in dB to the loss (in dB) caused by the coaxial cable inside the antenna. While the concepts are related, you can’t trade one for the other.

Is longer antenna better?

It all depends on what your transmitting and receiving frequencies are. Theoretically, a longer antenna will have a greater range, but it is far more important for optimal radio performance that the length of the antenna matches the frequency.

Can you use one antenna for multiple radios?

An element of filtering is required if you want to use two transmitters with one antenna. Diplexers allow either one radio to use two antennas, or two radios to share one antenna. The diplexers have filters that prevent transmitted RF energy from traveling into the second radio and causing damage.

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.

What do you need to set up to increase the range of your VHF radios?

The range of your VHF radio can be extended by elevating your antenna, increasing the quality of contact.

Can you use a CB antenna for a VHF marine radio?

Very different antennas. You could try to use the CB antenna for VHF reception ONLY but its performance would be less that ideal. Also, if you want to set up a VHF base station, and be able to LEGALLY transmit, you need an FCC base station license ($$$). It doesn’t work the same as Citizen’s Band.

Will a CB antenna work on marine radio?

Using a CB antenna will not give you proper performance and will probably damage the transmitter when you broadcast at 25 watts. Since VHF is line of site, the top of the mast is best, buy one designed for this location, as it will be the proper gain.

Do short radio antennas work?

The shorter antenna will give you reception somewhere between full length and nothing. For me I listen to AM a lot and the stock antenna is too sensitive around power lines. Removing it actually improves reception in most cases (eliminates that loud AC hum) so it wasn’t tough to go with a shorty.