CCVC: Best signals:
Position 1: F, K, H, B, Q
Position 2: T, Y, B, L, H, M, W
Position 3 vowel: E is best; U is clearly weakest
Position 4: H is the standout, followed by K, W, T, X, M, Y
Weak spots:
Position 1: Y, R, W
Position 2: X, Z, J, Q
Position 3 vowel: U
Position 4: L, F, J, G, V