| 摘要 |
PURPOSE:To prevent the variance of the parallerism of a balanced modulation type mixing circuit by providing cut parts at the prescribed positions of a printed distributing board to which four diodes forming a mixing circuit are attached and holding the diodes at those cut parts. CONSTITUTION:A balanced modulation type mixer of a tuner device is loaded to a printed distributing board 150, and this mixer consists of diodes D31-34. The diodes D31-34 are set opposite and in parallel to each other. While diodes D32 and 33 are set on both sides of a substrate of the board 150 so that they cross each other and are seen through from the board 150 at the middle part between the diodes D31 and 34. The cut parts 151-154 are previously provided to the board 150 at the areas where diodes D31-34 are set. The lengths of the parts 151-154 are set equal to or larger than the lengths of the D31-34. While the widths of the parts 151-154 are set smaller than the diameters of the D31-34. Thus the variance of the parallerism can be avoided for a balanced modulation type mixer by holding the D31-34 at the parts 151-154.
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