| 摘要 |
PURPOSE:To make it possible to receive the FM broadcasting wave also by adding a prescribed circuit to the wide band receiver of the double mixture system. CONSTITUTION:The wide band receiver of the double mixture system is provided with switching circuit 15 and tuning oscillator 29 which can switch the frequency. Now, when the FM broadcasting wave is received, switching circuit 15 is switched, and oscillator 29 is switched to a prescribed frequency. Then, the signal from wide band amplifier 1 is converted to the first IF signal by mixer 2 and tuning oscillator 3 and is supplied to mixer 5 through BPF4. This converted signal is mixed with the signal of oscillator 29 in mixer 5 and is converted to the second FM IF signal 19 and is supplied to sound FM detector 10 through IF amplifier 9. Next, this output is amplified by 11 and is supplied to speaker 12. Thus, the FM broadcasting wave can be received besides VHF and UHF-band TV broadcasting waves. |
