The RADIO port on the Postcard will feed either 3V3 (default) or 5V out. So yes, modifying the VSEL jumper to 5V should provide the LoRaSerial with additional gain.
The RADIO port on the Postcard will feed either 3V3 (default) or 5V out. So yes, modifying the VSEL jumper to 5V should provide the LoRaSerial with additional gain.