I just got a EmonTH clone working with the RFM69HW, using the JeeLib library. I changed the value of RegPaLevel by adding
writeReg(0x11, 0x5f);
after
rf12_initialize(nodeID, RF_freq, networkGroup);
This sets the power to 13bBm, same as RFM69CW. To increase power to 17dBm set 0x11 to 7F. To get 20dBm three other registers need to be modified. See, 3.3.7 High Power Settings, page 21 and 22 of the datasheet. Make sure to NOT use these settings for radios other than the HW.

1 Like