调幅广播频段中二极管调谐现在已有BB133型三连调谐二极管可用作调幅广播频段中的二极管调谐。此种二极管把三个相同的二极管组合在同一块硅晶体上,只有一个公用的阴极和三个分开的阳极。调谐电压为1伏时,其电容量为3×250微微法,当电压增长到30伏时,电容量下降到3×13微微法(图1)。二极管被封装在一个SOD-37型塑料壳内,有五根脚,阴极引脚有二根。对于一般的超外差式线路需要二只二极管,一只用于输入回路,另一只用于振荡器回路。第三只二极管可有各种用途。例如用 Diode tuning in the AM radio band The BB133 triple-tuned diode is now available for diode tuning in the AM radio band. This diode combines three identical diodes in the same silicon crystal, with only one common cathode and three separate anodes. When the tuning voltage is 1 volt, its capacitance is 3 × 250 picofarads. When the voltage is increased to 30 volts, the capacitance drops to 3 × 13 picofarads (Figure 1). The diode is packaged in a SOD-37 plastic case with five pins and two cathode pins. Two diodes are required for a typical super-heterodyne line, one for the input loop and the other for the oscillator loop. The third diode can have a variety of uses. For example