This is a small, cost-effective 915 MHz band pass filter with RF adapters for Helium Miners operating in Australia. The frequency range of this filter complies with miner frequencies for both AU915 and AS923.
The filter has a pass band of 916 MHz to 929 MHz. This is narrower than the 915 MHz filter for US915 frequencies. Insertion loss is typically 4 dB.
It has excellent out-of-band rejection specifications. Rejection at 900 MHz for instance, is typically greater than 30 dB.
The filter also provides power handling of up to a maximum +10 dBm with an operating temperature range of -40C to +85C.
The kit includes two RF adapters to connect to a Helium Miner
Reduction of Radio Frequency interference for Helium Hotspots*
Frequency Typical Insertion Loss
DC-800 MHz 40 dB
800-880 MHz 40 dB
960-1080 MHz 32 dB
1080-1500 MHz 40 dB
1500-3000 MHz 25 dB
*A Helium filter is beneficial if your Helium antenna is on the top of a building, tower or other location where there are LTE or cellular transmitters. It also benefits certain miners that have eliminated an internal SAW filter to save hardware costs. In many situations a filter may not benefit performance. In fact in some situations, it will degrade performance.
After adding a filter between the antenna and miner, we recommend leaving it in there and running your experiment for at least a week. The Helium network is very unstable and the frequency of beacons from neighboring hotspots can vary greatly for many different reasons. A week gives enough time to assess if a filter is beneficial or not.