Transmission of Television Sound on the Picture Carrier

Interference Characteristics of Pulse-Time Modulation

“…for small values of a/s, (~ < 0.2), such as will be encountered with interference ratios in the order of one-tenth or less, (or with reduced accuracy for higher ratios as well), it is merely necessary to evaluate the amplitude (10). Application of (9) yields…”

“…Physical reasoning provides the simplest way of obtaining this amplitude distribution of this function,since it has much in common with (10). Its value during exactly half of the period is +x, while during the remaining half it traces out the negative half of the cosine wave exactly as (10), except multiplied by a factor of two and moved upwards by an amount x. For this half of the function, therefore, the amplitude distribution curve has the appearance of the left half of the curve in Fig.…”

“…10 The exact type of time modulation, of course, has no bearing at all on the results obtained for the interference noise; only the demodulation process, so far assumed to consist of ordinary low-pass filtering, is of importance.…”