- Free reserves
- free route
- free time
- frequency agility
- frequency allocation
- frequency bandwidth
- frequency beat
- frequency changer
- frequency comb
- frequency compression
- frequency conversion
- frequency demodulation
- frequency departure
- frequency difference
- frequency doubling
- frequency factor
- frequency instability
- frequency inversion
- frequency jump
- frequency linearity
- frequency management
- frequency modulator
- frequency registration
- frequency selection
- frequency source
- frequency stability
- frequency synchronization
- frequency tracking
- front feed
- freephone call
- freephone number
- freephone service
- freewheeling diode
- frequency multiplication
- frequency octave
- frequency overlapping
- frequency pulling
- frequency standard
- frequency tolerance
- friction feed
- frontal disturbance
- frequency allotment
- frequency assignment
- frequency change
- frequency conservation
- frequency feedback
- frequency marker
- frequency offset
- frequency recording
- frequency separation
- frequency-modulated
- Fresnel lens
- Fresnel region
- full sweep
- function simulation
- functional capability
- functional counter
- fundamental availability
- fundamental quantity
- gain change
- gain function
- galactic cluster
- galactic equator
- galactic noise
- gamma distribution
- frequency average
- frequency demodulator
- frequency dissemination
- frequency diversity
- frequency doubler
- frequency generator
- frequency meter
- frequency multiplier
- frequency staggering
- fringe benefits
- front porch
- frozen capital
- frozen post
- fulchronograph
- full carrier
- full size
- full spool
- function byte
- function identifier
- functional unit
- Funded debt
- gain control
- gain drift
- galactic pole
- galilean system
- gap loss
- gain curve
- gain error
- galactic cloud
- galaxy cluster
- gas diode
- function check
- function measure
- function table
- functional subsystem