What transformer turns ratio matches an antenna's 600-ohm feed point impedance to a 50-ohm coaxial cable?
Why Transformers change impedance as the square of the turns ratio: Z_primary/Z_secondary = (N_primary/N_secondary)^2. Here the impedance ratio is 600/50 = 12, so the turns ratio is the square root of 12, about 3.46, which rounds to 3.5 to 1.
Watch out The choice of 12 to 1 is the impedance ratio itself, not the turns ratio; squaring 12 would give a 7200 to 50 transformation.
Turns ratio = square root of impedance ratio. sqrt(600/50) = sqrt(12) = 3.5.