why is the height of a vhf radio antenna important

Why is the Height of a VHF Radio Antenna Important? – Overview, Tips, FAQs & More

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When you install a VHF radio, the positioning of the VHF radio antenna is arguably one of the most important aspects. 

If done improperly, you’ll find yourself running into a slew of issues such as distortion, difficulties in tuning, and more. 

This post discusses why the height of a VHF radio antenna is important and how you can get the best performance out of it.

Quick Summary

In this post, we will shed light upon 

  • What a VHF radio is 
  • Why the height of a VHF radio antenna is important
  • How to pick the most suitable VHF radio antenna 
  • How to extend a VHF radio antenna’s range
  • Some frequently asked questions (FAQs) 

So without further ado, let’s get into it.

What is a VHF Radio? 

A VHF (Very High Frequency) radio is one of the most common types of radios that are used for communication outdoors. It’s what most people bring with them on camping and boating trips to maintain contact with the outside world. 

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It’s a short-wave radio which means that the radio waves that are emitted from it do not bend to follow the curvature of the Earth. As a result of this, the radio waves do not reach beyond the horizon. 

Radio waves that are emitted from a VHF radio can easily be obstructed by large structures such as buildings, mountains, containers, etc. This is one of the (many) reasons why the height of your VHF antenna is important. We’ll look at this in more detail in the next section. 

Why is the Height of a VHF Radio Antenna Important?

The easiest way for you to understand why the height of a VHF antenna is important is because communication between VHF radios depends on “line of sight”. This essentially means that you can only communicate between two VHF antennas that are within sight of each other. 

Since this is the case, that means that the higher up your VHF radio antenna is, the longer its range will be. Antenna height is a factor that determines how far your VHF radio will be able to communicate. 

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Think of how far you are able to see. 
If you’re on the ground, you’ll only be able to see a certain distance ahead as your vision will be blocked by structures such as buildings, hills, etc. 
However, if you go on top of a large structure such as a tall building, you’ll be able to see much farther. 
VHF radios pretty much operate on the same principle. 
A VHF antenna that is on the ground will have a much shorter line-of-sight (and thus, much shorter range) compared to an antenna that’s on top of a roof. 

They emit the radio signal from the VHF antenna and the signal travels in a straight line in every direction. If there are other VHF antennas within the line of sight of the origin source, then they’ll receive these radio signals and unscramble them for their corresponding users to hear. 

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How to Pick the Most Suitable VHF Antenna?

We’ve discussed how the height of a VHF radio antenna can affect its range but that’s not the only factor that determines its overall performance. 

When you go out to buy a VHF radio antenna for yourself, there are many other factors to consider as well. 

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These factors include: 

dB Rating 

To start off, you must consider the dB rating of your VHF radio antenna. The dB (Decibel) rating of an antenna essentially refers to how powerful it is. 

You might think that the highest possible dB rating would be best but that’s not always the case. It usually depends on where you intend to mount the antenna. 

For example, if you intend to mount the VHF antenna on a boat, then you’ll have to consider the size of your boat. 
In most cases, boats that are smaller than 24 feet will work best with antennas with a dB rating of 3 dB. 
On the other hand, boats that are larger than that will usually require a VHF antenna with a minimum dB rating of 6 dB. 

You must also consider whether or not you intend to have the antenna mounted on a stationary object or one that will be moving. 

If you’re in a car or a boat, for example, then a dB rating of 3 dB is usually more than enough in most cases. However, if you intend to mount it on your roof, then you’ll have to buy something with a dB rating of at least 6 dB. 

Length and Adjustability 

We’ve already discussed that for your VHF transmissions to be effective, your antenna has to be as high as possible. 

In this case, naturally, it’s a good idea to invest in a VHF antenna that is as long as possible so that your VHF signals reach far and wide. In addition to being long, it’s also a good idea to find a VHF antenna that offers room for adjustability. 

Many VHF radio antennas come with the capability to adjust their height so that they can be utilized for a number of different applications. 

If you get a VHF antenna that is adjustable and does not only work at one height, you can take advantage of its flexibility. 
For example, when you’re at home, you can work with it at its fullest length. This will allow your VHF communications to reach far and wide. 
However, if you want to use it with your car at a later time, then the full length of the antenna might not be practical. It might be too high to be mounted on a car. In this case, you can shorten its height a little bit so that it fits well. 
An adjustable antenna is a versatile antenna.

Important note: It can be a good idea to buy a coaxial cable that is quite long. This will give you the freedom to mount your antenna much further away from wherever your VHF radio is. Naturally, this can open up a lot of options for you to effectively transmit radio frequencies.

Build Quality

It’s a good idea to buy your VHF antenna in person rather than buying it online since you’ll be able to inspect it thoroughly. 

Make sure that you buy the VHF antenna from a reputable manufacturer and not an obscure one. You should also read some online reviews and do your research to ensure you buy one that’s made from materials that will work well for your particular application. 

Most cheaply built antennas are made from Nylon ferrules. You should avoid those. 

In most cases, the best option is to go for a VHF antenna that is built from Fiberglass or stainless steel. That being said, their quality and lifespan can still vary from brand to brand. 

Learn all there is to know about Radios, how to resolve their issues, and more on our website.

How to Extend a VHF Radio Antenna’s Range?

There are a number of things you can do to increase the VHF radio range of your antenna. 

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Here’s what you can do: 

Position Your Antenna as High as You Can 

This is something we’ve highlighted constantly throughout this article but it should be reiterated: You should strive to have your antenna as high as possible. 

That’s why we mentioned how you should invest in a long coaxial cable (the cable that connects your antenna to your radio). 

A long coaxial cable means that you can safely have your radio inside your house or wherever you want to keep it. On the other hand, you can have the antenna on the highest point of your roof so that its VHF range is as high as possible. 

Choose the Right VHF Radio 

In addition to your VHF antenna being the correct choice, you must also consider your VHF radio with care. 

The higher the wattage of your VHF radio, the stronger and clearer the VHF signal will be.

Higher-quality VHF radios can sometimes be more expensive. However, it’s a much better choice than saving money and ending up with a radio that offers unclear communication. 

Utilize the Appropriate Battery 

When it comes to VHF radio communication, it’s important to pay special attention to the power source. 

Make sure you read the instruction manual provided by the VHF radio manufacturer. 

They’ll always have a recommendation for what type of battery to use. The most common choice for most VHF radios is 12 volts which produces the clearest and strongest signal. 

If you use batteries that are weaker, this can affect your VHF radio range as well as the quality of the transmitted signal. 

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Frequently Asked Questions (FAQs) 

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Can I use more than one VHF antenna? 

Yes, you can definitely use more than one VHF antenna to further increase the power and range of your radio signal. 

However, it’s important that they be set up at a fair distance so they don’t interfere with each other. A separation of at least 6 feet both horizontally and vertically is usually more than enough.

What are VHF antennas used for? 

You can use VHF antennas paired with your VHF radio for two-way communication and also, for weather alerts. 

You can also access VHF TV stations as well as FM radio. 

How long do VHF antennas last? 

They can vary by quite a bit. Some VHF antennas last only 1 to 2 years whereas others can last for up to 10

It depends on a number of factors such as external weather conditions, the build quality of your VHF antenna, as well as how you treat it. 

Do I need to tune my VHF antenna? 

Most VHF antennas that are sold today are pre-tuned which means that you don’t have to spend time trying to tune them. 

Does a marine VHF radio need an antenna?

Yes. A VHF antenna is necessary for your marine VHF radio’s transmissions to be heard by other radio operators. 

Wrapping Things Up… 

That’s why the height of a VHF radio antenna is super important when it comes to VHF communication. 

We hope this post was helpful and you were able to get some pointers on how to get the most out of your VHF radio and antenna. 

If you have any further questions or queries, please feel free to reach out in the comments section below. 

Check out more information on all types of radios, how to use them, and more on our website.

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