I have just set up a new EmonTx V3.4.
I downloaded latest firmware.
The only change I made was set boolean RF_STATUS = 0; as I did not want to use the on board RFM.
I am not using AC adaptor so removed jumper.
Both dip switches are off.
Powering from USB.
ESP worked as expected with browser access.
Working fine as far as I can tell except the Vrms is reporting 523.
Have I missed a setting I should have changed in the firmware?