FYI: RadioHead library 1.34 has some specific initialization code for RFM73 in the nRF24 driver (e.g. ACTIVATE command).
Yveaux committed to Yveaux/RadioHead
1.34 2014-09-19 Fixed compile errors in example rf22_router_test.
Fixed a problem with RH_NRF24::setNetworkAddress, also improvements to RH_NRF24 register printing. Patched by Yveaux.
Improvements to RH_NRF24 initialisation for version 2.0 silicon.
Fixed problem with ambigiguous print call in RH_RFM69 when compiling for Codec2.
Fixed a problem with RH_NRF24 on RFM73 where the LNA gain was not set properly, reducing the sensitivity of the receiver.
I'm wondering what the minimum input voltage is. The description only says max. 6.5V input voltage from the battery, but does not say what the minimum is. Both the nrf24l01+ as well as the atmega328P work with 3.3V, so if I use three AA batteries, that should be fine, right? I suppose using two AA batteries is not enough?