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本文叙述了PULSAM调幅方式,它是脉宽调制(P.W.M.)的一种新应用。文中研究了与新型调制器设计有关的问题,并与已有的串联脉宽调制原理进行了比较,从中可以看出新方式是有利的。在PULSAM方式中,开关调制器只是用来转换边带功率,射频载波管从另一单独的电源取得功率。这样就有个优点,即射频放大器(即被调级——译注)可以在关掉调幅器的情况下进行初始调谐,并维持工作。PULSAM方式的电路元件一般比串联脉宽调制设备中起相同作用的元件要简单,这主要是由于转换的功率很低。同样,由于开关频率所引起的杂波辐射电平也被减小了。第一部采用这种调幅器的发射机是马可尼B6127型500千瓦短波广播发射机。
This article describes the PULSAM amplitude modulation method, which is a new application of pulse width modulation (P.W.M.). In this paper, the problems related to the new modulator design are studied, and compared with the existing pulse width modulation principle, it can be seen that the new method is beneficial. In PULSAM mode, the switch modulator is only used to convert the sideband power and the RF carrier pipe takes power from a separate power supply. This has the advantage that the radio frequency amplifier (ie, tuned - translator) can be tuned in the initial tuning off, and maintain the work. Circuit elements in PULSAM mode are generally simpler than those in series-connected pulse-width modulation devices that function in the same way, mainly due to the low conversion power. Similarly, the level of clutter due to the switching frequency is also reduced. The first transmitter to use this modulator was the Marconi B6127 500 kW shortwave radio transmitter.