| 摘要 |
PURPOSE:To attain low cost by simplifying constitution by using part of the 2H delay line of a comb line filter for PAL as a comb line filter for NTSC. CONSTITUTION:The macro center frequency of an NTSC signal to be reproduced is 4.43MHz, which is equal to that of PAL. The horizontal period or vertical period of the reproduced NTSC signal is not its original one but the period of PAL. For this purpose, the capstan servo system changes over the output of reference oscillator 50 via switch 45 so as to obtain horizontal frequency (f) of PAL by changing a tape speed. Further, delay line 14 is so constituted that it can be used as a comb line filter for NTSC reproduction. |
