Get the right length VHF Antenna
Figure out how long your antenna should be on your VHF Radio.
It is quite simple to figure out what your antenna length should be. Of course there are other factors that enter into the decision but it is really quite simple to figure your required antenna length.
First figure out how far you have to go to the radio you are going to communicate with. If it is a fixed base radio at your cabin you can get better coverage because you can mount the antenna on the cabin roof.
Basically, for 1.4 miles you need one foot of antenna. If you have two radios, both with 3 foot antennas you divide the number of miles you need to cover by 1.4 and round up to the nearest whole number. Divide it in two if you know both radio positions.
If you do not know the receiving antenna length just use an average of 3 feet (three feet times 1.4 is 4.2 miles) and you know how far away you will reach the other radio.
Because you both can reach out 1.4 miles for each foot of antenna, you can double the mileage that you can effectively reach.
If that confuses you just follow the links below to get a more detailed overview of how it all works.
Here is a formula for calculating the range of an antenna:
Calculation for Range of an Antenna:
Square Root of Height (in feet) above water x 1.42 = Range in miles
Remember to perform the calculation for BOTH vessels, and then add the results to get the range between two vessels.
Choosing an antenna
This is a great write up from the Shakespeare website on how to select and mount a VHF antenna.
Antenna Mounts
Great site for reviewing the different antenna mounting solutions available
It is quite simple to figure out what your antenna length should be. Of course there are other factors that enter into the decision but it is really quite simple to figure your required antenna length.
First figure out how far you have to go to the radio you are going to communicate with. If it is a fixed base radio at your cabin you can get better coverage because you can mount the antenna on the cabin roof.
Basically, for 1.4 miles you need one foot of antenna. If you have two radios, both with 3 foot antennas you divide the number of miles you need to cover by 1.4 and round up to the nearest whole number. Divide it in two if you know both radio positions.
If you do not know the receiving antenna length just use an average of 3 feet (three feet times 1.4 is 4.2 miles) and you know how far away you will reach the other radio.
Because you both can reach out 1.4 miles for each foot of antenna, you can double the mileage that you can effectively reach.
If that confuses you just follow the links below to get a more detailed overview of how it all works.
Here is a formula for calculating the range of an antenna:
Calculation for Range of an Antenna:
Square Root of Height (in feet) above water x 1.42 = Range in miles
Remember to perform the calculation for BOTH vessels, and then add the results to get the range between two vessels.
Choosing an antenna
This is a great write up from the Shakespeare website on how to select and mount a VHF antenna.
Antenna Mounts
Great site for reviewing the different antenna mounting solutions available
Topic Tags: fixed mount vhf radio, marine antenna, marine radio, marine vhf antenna, shakespeare antenna,
0 Comments:
Post a Comment
<< Home