Last update on April 23, 2022
We've got some prototypes of our new Helium amplifier in-house and they are currently being tested. Over the past month we have been studying the performance of a Helium Miner with and without the amplifier.
The miner is placed in the attic with the stock plastic antenna that has 3 dBi gain.
We looked at the RSSI vs SNR values for one particular hotspot's beacons over time. Here are the results with and without the amplifier
- The measured gain of the amplifier (in the lab) is about 13 dB
- The average improvement in RSSI with the amplifier is about 8 dB
- The average improvement in SNR with the amplifier is about 4.2 dB.
Main Issues faced
Network instability - This has been very disruptive and makes it difficult to test consistently across the wider Helium network in our neighborhood. A meaningful number of measurements are required to establish that there are improvements in both RSSI and SNR with the use of the amplifier.
Miner instability - We started with a RAK v2 miner but ran into issues with flat lining (off-lining?) due to the SD card issue. The RAK miner was replaced with the Nebra indoor miner.
In order to make a meaningful comparison we had to start all over again with the Nebra.
- In the attic, we don't have line-of-sight between the transmitter and the receiver
- The variation between min and max SNR is about 13 dB both with and without the amplifier (you really can't tell if there are improvements with the LNA based on one or two measurements)
Things to try
- Try different antennas
- Additional filter before and/or after the amplifier
- Attenuate the signal by 3 dB after the amplifier
- Experiment with line-of-sight