Abstract: A wide band, transistorized power transmitter for the execution of radio traffic requires a filter arrangement consisting of a large number of sub-filters because of the insufficient linearity of the transmitter end stage between the output of the transmitter end stage and the transmitter output. Depending upon the adjusted transmitter frequency, in order to suppress undesired harmonics, one of the sub-filters is switched into the signal path. The relays normally used to switch on and off the sub-filter are unsuitable for carryout out frequency jump operation. By effecting a suitable sub-division of the sub-filters of the filter arrangement into two and more sub-filter groups, between which it is possible to carry out a rapid and non-abrasive switch-over by way of electronic power switches, it is possible without too high an expense to carry out a frequency jump interval which can be arbitrarily adjusted within the overall frequency range.

Abstract: A transistor power amplifier for transmitting systems, particularly high frequency systems, has two parallel connected signal paths each of which is fed with the input signal. In a first of the signal paths, a 6 dB attenuator connects the input to the input of an amplifier and a fraction of the output of the amplifier is connected to one input of a correction amplifier, constructed as a differential amplifier. In the other signal path a delay member which simulates the delay of the first amplifier connects the circuit input to another input of the correction amplifier. The correction amplifier therefore is provided with a fraction of a delayed amplified signal which is subjected to error and includes an error component and with the delayed original input signal and emits a control signal for a second amplifier in which the error component produced in the first amplifier is contained in a double and inverted magnitude.