| 摘要 |
Transistorised power transmitters for carrying out radio traffic, as are used, in particular, in short-wave radio, use several power output stages (LV1, LV2, ... LV4) as output amplifiers which are combined at the output side via a network (N) consisting of hybrid circuits and transformers to form a sum output (sa) which then outputs the signal output powers of the individual power output stages, which have been added with the same phase, to a sum output line (la). To save direct-current input powers to such an output amplifier with reduced rated output power, it is proposed optionally to switch through the outputs of the power output stages (LV1, LV2, ... LV4) or the outputs of two power output stages (LV1/LV2, LV3/LV4) which have been combined to form a further output, with the aid of change-over switches (U1, U2, ... U6) and other switches (S1, S2, s1, s2, ... s4) to the sum output line (la) while simultaneously switching off the remaining power output stages. In this manner, the direct-current input power can be correspondingly reduced with reduced rated output power of the transmitter output amplifier. <IMAGE> |
