The transmitting amplifier "Step-103" (8UP1-100-103) since 1990 has been produced by OAO Slavgorod Radio Equipment Plant. Amplifier "Step-103" is designed to amplify the phonograms from microphones, EDA, tape recorder, receiver, etc. It is used for the organization of local broadcasting, alerts at industrial enterprises, trade, education, health care, culture, etc. The amplifier provides: mixing signals; input jacks for connecting 4 microphones, sound pickup, tape recorder, receiver, broadcasting line; output jacks and terminals for connection: tape recorder to record, radio voltage of 30 V, transmission line voltage of 120 V, transformerless speakers (8 Ohms), control loudspeaker, power amplifier input; smooth gain control on the inputs for connecting microphones and sound pickup; smooth adjustment of frequency response separately for low and high frequencies; switchable devices noise reduction and loudness; turning off the frequency response regulators; protection against short circuit and overload at the output; indication of the output voltage level; acoustic control through an external loudspeaker; microphone connection with balanced output through balancing devices. Specifications Maximum output power 100 watts. The reproducible range of sound frequencies at the outputs for broadcasting lines is 40 ... 16000 Hz, for acoustic systems 31.5 ... 20000 Hz, at the linear output 20 ... 20000 Hz. Irregularity of the frequency response in the nominal range is often no more than 1.5 dB. Harmonic factor 0.5 ... 2%. The depth correction frequency response of not less than ± 15 dB. Power - electricity. Power consumption not more than 250 watts. Dimensions of the amplifier 470x140x360 mm. Weight 22 kg. The amplifier comes with 2 microphones, 2 baluns and a linear shield.