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How to Choose an Antenna for Your Helium Hotspot?
The Helium network is the fastest growing decentralized LoRa network in the world. The coverage that Helium network can offer, would be a game changer for the adaptation of the IoT devices more into the everyday life. In this journey, HotSpot owners perform the most vital task by deploying the Helium HotSpots to increase the coverage. As a reward for this important work, Helium blockchain rewards HotSpot owners with Helium cryptocurrency(HNT). In search of HNT, there are many things HotSpot owners can do to maximize their earning potential.
“How can I mine more Helium?”
Two key things that determine the earning potential…
- The placement of the HotSpot
This is the location of the HotSpot. Making sure the location of the HotSpot is an adequate distance away from any other miner. Helium Explorer is a great tool to determine the location.
- The coverage offered by the HotSpot
The antenna used with the HotSpot and the elevation from the ground determine the coverage offered by the HotSpot.
In this we’ll focus on the choice of antenna to maximize the earnings…
Let’s keep this less technical and to the point. First thing anyone looking for a suitable antenna should check is the correct frequency they need.
- 470 Mhz – CN470
- 868 Mhz – EU868, IN865, RU864
- 915 Mhz – US915, AU915, AS923, KR920
As you can see, there are 3 main frequencies of antennas in the market and getting the right frequency compatible with your region is vital. You can go to this link here and check by your country to make sure which frequency is compatible.
“What is Antenna Strength..?”
Antenna strength can be simply thought of as the power of the signal the antenna sends out. One key thing to remember is that the way antenna increase the power of the signal is by concentrating the power coming to the antenna into narrower trajectories. The picture below show some of the most common antenna dBi in the market and their RF coverage.
You can think of this as how a flashlight can concentrate a beam of light. If you take the bulb by itself, the light spreads everywhere with less intensity, but when you put the bulb inside a flashlight, it focus the light into a specific direction with higher intensity. This allow light to reach further out. Similar concept is used here by the RF antennas. Due to this high dBi wouldn’t necessarily mean better coverage. Look at the scenario below.
As visible here, the location of the HotSpot relative to the other buildings makes the use of a 9dBi antenna not suitable, since the RF coverage goes over the rest of the building. However, the use of 2dBi antenna provides a better coverage. So the take away is more powerful doesn’t always mean the best in RF world; It’s all about how to provide the best coverage in the terrain you are in.
What about uneven terrain like below???
In a terrain like this a 2dBi antenna with a spherical coverage would be not suitable, given the other miners are few and further apart. A 5 dBi antenna with a narrow and far coverage can be much suitable. Further, in a terrain like this with mountains, the propagation of the RF signal can take more than just line-of-sight signals.
Now generally with antennas, line-of-sight would be the best case scenario. Line-of-sight is basically your antenna being in the line-of-sight of the receiving antenna. However, radio waves travel even when there is no line-of-sight, through phenomena such as reflection and diffraction of waves.
As seen above the RF signal can bend around large structures. Now these signals are not the best in reliability, but they can be a huge help to reach HotSpots that are not in direct line-of-sight. However, to achieve this efficiently the dBi of the antenna should be higher.
Once I get an antenna, how should I place it?
This is a very important questions. You should try to place your antenna as high as you could, so the antenna does not have any obstacles in its way. If you live in the 24th floor of a high-rise, you are already in a great place. Just keep it by the window overlooking outside.
What if you live on a one story house? Well in that case you should try to place the antenna as high as you could inside the house or better yet outside the house. Some people keep the HotSpot inside the house and draw the antenna cable outside to where the antenna is at a good position(Beware- Long cables can reduce the strength of the antenna and generally a 3ft cable would be the best length). You can place the antenna on your roof, outside a window or on a dedicated pole outside.
It’s always better to reduce the number of barriers between your antenna and the other miners outside. Your house walls, window glass and even house trees falls under the category of barriers.
Is an indoor or an outdoor antenna better?
The stock antenna that comes with most miners are rated for indoor use and should not be places outside. But getting an outdoor antenna and placing it outside reduces the barriers mentioned earlier and that generally makes an outdoor antenna more useful.
What about the antenna my HotSpot came with?
Well that antenna is usually a 2dBi(Rak, Nebra miner, etc.) or a 4dBi(Bobcat) antenna, and is good enough for most miners that are in well populated areas with lot of miners around. So don’t go around buying antennas without considering the location well.
One important thing with outdoor antennas: Lightning arrestors
These will not protect your antenna from a direct lightning strike. Only a lightning conductor can do that- Warning to make sure your antenna is in place that is not prone to get hit by lightning. What a lightning arrestor will do is protect your device from the static build up that happen during storms. These static build up can be bad and any ham radio operator knows the trouble they can cause. So it would be smart to get a lightning arrestor and attach it to your antenna. You can get one from shop.iotoffgrid.com
Some helpful items that will come handy:
- Waterproof and high temperature electrical tape
- Self-bonding silicone tape
- Antenna mounting poles(check Amazon for a suitable one)
Hopefully this article was helpful. Please comment any questions and share if you found this useful.
