RE: Futaba 4YF 2.4GHZ FHSS Radio
From the Tower website: >> REQUIRES: AA Batteries: Four for transmitter
SPECS: Transmitter; Transmitting Frequency: 2.4GHz band Power Requirement: Four AA cells Current Drain: 90mA Trainer Port: Micro Receiver; Power Requirement: 4.8 - 6V shared with servo Current Drain: 30mA at no signal