Low frequency amplifier "ULF-3".

Amplifying and broadcasting equipmentThe low frequency amplifier "ULF-3", presumably since 1960, has been produced by the Odessa experimental plant "Krasny Oktyabr". The ULF is assembled on octal radio tubes 6N9S, 6P6S and a kenotron 6Ts5S and is intended for a school physics classroom, where it was possible to demonstrate sound amplification from a microphone, pickup, detector receiver, etc. The amplifier into a 3.6 Ohm load develops an output power of about 4 watts. Sound frequency range 80 ... 8000 Hz. Sensitivity from microphone 3.5 mV, pickup 100 mV. Power consumption 50 watts. Amplifier dimensions 230x180x150 mm. Weight 3.7 kg. Presumably, since 1969, the plant has been producing the same amplifier, but on 6N2P, 6P14P finger-type radio tubes and 6Ts4P kenotron.