Measuring and checking device of circuit substrate

Abstract

Abstract PURPOSE:To improve the space efficiency and the control workability and at the same time to solve the problems including the tape deterioration, etc. in order to improve the control accuracy, by incorporating a signal generating circuit, an FM demodulator, a wave detecting circuit, a frequency counter, a frequency converter, a display device, etc. into a single housing. CONSTITUTION:The FM signal supplied to an input terminal 54 is equal to a frequency multiplex signal containing the right and left channel FM signals obtained in a no- modulation mode. This multiples signal is supplied to land pass filters 56L and 56R respectively through a buffer amplifier 55. Then the FM signal is branched into three parts by distributors 57L and 57R and supplied to FM demodulators 61L and 61R, mean value wave detecting circuits 62L and 62R and contacts L and R of a switch 58, respectively. The frequencies are counted first by a frequency counter 59 and this count value is displayed digitally to a frequency display device 60. Then an FM-demodulated sine wave of 1kHz is taken out of demodulators 61L and 61R of a PLL wave detection system and supplied to a modulation degree display device 63. Thus the measurement/ check and control are possible for the FM modulation degree. Furthermore various types of measurements are possible for a reproducing circuit with no use of the reproduced signal of a magnetic tape when a measurement signal is supplied to the reproducing circuit.

Inventors

• 👤 Tsutomu Ishii
• 👤 勉 石井

Bibliographic Details