| 摘要 |
PURPOSE:To obtain a pattern with high quality similar to that in using an external antenna by providing an RF amplifier circuit and inputting a received radio wave to a tuner through the RF amplifier circuit at the reception by a rod antenna. CONSTITUTION:The video and sound wave received by a rod antenna 1 is subjected to gain correction by an RF amplifier circuit block 3 so as to be controlled at the optimum sensitivity and the amplified signal is inputted to a tuner block 4 through the input changeover switch of an external antenna input jack 2. On the other hand, in pugging an input plug 6 connected with an external antenna 5 to the external antenna input jack 2, the input changeover switch interrupts the input from the rod antenna 1 and the input from the exter nal antenna 5 is inputted directly to the tuner block 4 not through the RF amplifier circuit block 3. Thus, at the use of rod antenna, the excellent picture with high quality similar to or more than that with the external antenna usage is obtained even under bad reception condition, as in a cabine by using the rod antenna.
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