Lopy Lora radio oscillator frequency stability specs available?
The Lora chirp type modulation requires a very stable oscillator in order to get the best long distance results. Some Lora modules use a 10 ppm crystal, some a TCXO at the expense of a high power consumption. Semtech advises a 0.5 ppm TCXO in www.semtech.com/images/datasheet/an120014-xo-guidance-lora-modulation.pdf. What crystal or oscillator is used in the Lopy?
You do not need 0.5 ppm at least not for 125/250/500 kHz bandwidth.
I'm not sure about the original LoPy - was before my time at Pycom (last month) - but the LoPy4 comes with a TCXO.
Also it has a SX1276 instead of the SX1272