Abstract
It is proposed to deal with some points relating to modulation in a simple Valve Transmitter. Only the most common methods will be considered.
The work can be divided into two parts. The first dealing with the effects in the modulation transformer, which is suitable for mathematical treatment, and the second dealing with the oscillating circuit and effects due to properties of the valve. The latter part becomes essentially an experimental analysis from the results of which certain deductions can be made. No attempt has been made to analyse the effects in a microphone and it is assumed that the microphone and battery in series with the primary of the modulation transformer give a current in it which varies exactly as the pressure of the impinging sound waves. [Extact from Page 1]