Abstract: Binary information signals which are to be transmitted are combined with a pseudo-random signal wave form such as a pseudo-random sequence of binary bits. Each binary message element, whether a binary "1" or a binary "0", alters successive portions of the pseudo-random binary sequence to thereby create a modified pseudo-random binary bit sequence, successive portions of which represent the binary information. The successive portions of the modified pseudo-random binary sequence are converted to an analog quantity which will be similarly varying in a pseudo-random manner.