Director
975/F

Full Wave Driven Element
1005/F

Reflector
1030/F

Spreaders
A2 + B2 = C2

Polarization
Fed on the side = Vertical polarization (VHF)
Fed on the bottom = Horizontal polarization (HF)

Matching Stub (75 Ohms)
984/F x Velocity Factor divided by 4

Calculator
Cubical Quad Antenna Calculator (Will include spacing)

Note
A cubical quad antenna is based on a full wave legth, where a yagi antenna is based on a half-wave length.