I 've made a Lora pair (Sender & Receiver) using Lora RA-01.
It's working with the spring antennas that come with the module.
I gave it to a client.
Now I 've made a replacement of it, a pair of Loras using Lora RA-02.
I 've tried every possible antenna type (spring, whip half length, whip 1/4 length, dipole).
Also tried to maximize range with software:
LoRa.setSpreadingFactor(12);
LoRa.setSignalBandwidth(62.5E3);
LoRa.setCodingRate4(8);
But I have not managed to get the range of the first pair (which works with the default SpreadingFactor, Bandwidth and CodingRate).
I get less than half of the range.
How is it possible the spring antenna (which is supposed to be crappy) on RA-01 to perform so much better than any other antenna I 've tried on RA-02?
(or maybe it 's not the antenna but something else?)