At the front end of the mid-wave broadcast transmitter, the audio signal highly processed by the audio processor will contain many flat-top waveforms similar to square waves. The amplitude and phase response of the square wave's waveform to the transmission path it passes is relatively high. In principle, in the frequency range of the main energy of the program, if the flat amplitude and the group delay are deviated, the flattened top of the processed audio signal will be tilted, thereby increasing the peak modulation voltage, but the average level is not increased.
From the peak/flat ratio value, the average level of the path is reduced, and the loudness is correspondingly reduced. In this regard, we have to maintain the prototype of the processed signal waveform. The first method adopted is to select a transmission cable with high quality and excellent performance in the use of transmission signal cable, and require a copper core transmission line with small distribution parameters, frequency bandwidth, small wire diameter, low attenuation, and good shielding performance. This is very important and very effective. In addition, in the transmission connection, try not to add any additional equipment and branch components, such as intermediate amplifiers, distributors, etc., to reduce signal waveform distortion and ensure good transmission quality.