Families of codes from orthogonal (0,1,-1)-matrices

Sloane and Seidel have constructed (n,2n,1/2(n-2)) and (n-1,2n,1/2(n-2)) codes whenever n = 1 + a2 + b2 = 2(mod 4), a,b integer, is the order of a conference matrix. We give constructions for (n,2n,1/2(n-2)) and (n-1,2n,1/2(n-4)) codes when n = 2(mod 4) and conference matrices cannot exist. In particular we give results for n = 22, 34, 66, 70, 106,130,154,162,202,210, ... ,"210, ... , but our codes are not as ""good" as those from Hadamard matrices or of Sloane and Seidel".