The practical range of an 8 dBi antenna is around 60 km or 37 miles across an open area.
Let’s get into the details
What does dBi mean?
dBi stands for dB gain relative to an isotropic antenna. An isotropic antenna is one that radiates equally in all directions. The higher the gain, the more focused the energy radiating out of the antenna. Antenna gain is determined by the operating frequency and antenna factor.
This focusing of energy does not come for free. Let’s take a look at the picture below that shows antennas with different gains.
The higher the dBi number, the more focused the beam.
How does a high dBi antenna improve performance?
A high dBi antenna helps focus the signal out of and in to the antenna. In doing this it dissipates less energy in all directions and favors one.
A high dBi gain antenna is therefore able to reach further. This is useful if you want to listen to or witness beacons from miners that are in locations with a transmit scale of 1. This maximizes HNT earnings.
Can a high dBi antenna reduce my rewards?
Yes, in some situations a high gain antenna can reduce rewards relative to a lower gain antenna. Most miners ship with a stock antenna that’s either 2 or 3 dBi. As shown in the picture above these antennas have a uniform radiation pattern. If you are on the top of a tall building and use a high gain antenna, there is a good chance you will over-shoot and not be able to witness beacons that are at a lower level relative to the antenna.
Theoretical Range of 8 dBi antenna
Using the standard free space path loss calculation (in theory) it’s possible to get a range of about 500 km with an 8dBi antenna. But this assumes an ideal situation where there are no obstacles between the transmitter and receiver and the signal is propagating in free space.
Practical Range of 8 dBi antenna
In practice we are seeing transmissions in the range of 60 km with an 8 dBi antenna under a nearly ideal situation – i.e. across an unobstructed body of water.
There are two things that make this possible:
- The beaconer in this case has an 8 dBi antenna that’s placed 50 meters above the ground level
- There are no obstructions in the lake
This enables a longer range than in the city for instance where there are many impediments to the signal transmission.
In this post we have discussed both theoretical and practical range achievable with a Helium miner when using an 8 dBi antenna. We have found that in a practical operating environment it should be possible to get 60 km or 37 miles of range.