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数字技术的进展已经使人们能够研制新型的数字式自动电视信号测量系统,这就是ANSWER Ⅱ。五年前,第一个ANSWER系统,因为模拟方法太复杂而没有投产(当时还无法采用数字技术)。ANSWERⅡ系统的核心是Tektronix公司为NTSC和PAL电视研制的一种8位20兆赫模-数转换器(ADC)。为了尽可能得到最好的性能,便用了最新的集成电路技术。就在ADC的研制过程中,微处理机(单片计算机)和可编程序只读存贮器(PROM)已成为商品,并被纳入设计。本系统一个重要的特点是它在量化时使用了四倍付载频。只要改变PROM就可以改变规定的测量程序。本文展示了某些重要应用,并指出ANSWER Ⅱ最后可能在很多重要的工程应用中取代示波器和矢量仪。
Advances in digital technology have led to the development of a new digital automatic television signal measurement system. This is ANSWER II. Five years ago, the first ANSWER system was inoperable due to the complexity of the simulation method (digital techniques were not available at the time). At the heart of the ANSWER II system is an 8-bit, 20-MHz analog-to-digital converter (ADC) developed by Tektronix for NTSC and PAL televisions. In order to get the best possible performance, they use the latest integrated circuit technology. Just as the ADC was being developed, microprocessors (monolithic computers) and programmable read-only memories (PROMs) became commercial products and incorporated into the design. An important feature of this system is that it uses four times the carrier frequency for quantization. As long as the PROM can be changed to change the prescribed measurement procedures. This article shows some important applications and points out that ANSWER II may eventually replace oscilloscopes and vector machines in many important engineering applications.