目前,在我国煤田地震勘探中普遍采用的是TYDC-24型磁带地震仪。该仪器的振幅控制系统由初始增益控制、自动振幅控制和公共增益控制三部分组成。前二者通过放大器第一衰减桥实现,后者通过放大器第二、第三衰减桥实现。我队在使用该仪器进行生产的过程中,曾发现如下现象:①每当激发条件变坏,需加大药量激发时,便在记录头部产生“压死带”与“超调带”严重地破坏了浅部同相轴,对连续追踪浅层反射极为不利;②在 At present, the TYDC-24 tape seismograph is widely used in the coalfield seismic exploration in our country. The amplitude control system consists of three parts: initial gain control, automatic amplitude control and common gain control. The first two are realized by the first attenuation bridge of the amplifier, and the latter is realized by the second and the third attenuation bridge of the amplifier. My team in the use of the instrument for the production process, have found the following phenomena: ① Whenever the excitation conditions deteriorate, need to increase the amount of stimulation when the record head will have a “crush band” and “overshoot band” Seriously undermining the shallow facies, which is extremely unfavorable for continuous tracking of shallow reflection