The set for the radio amateur &quot;Low Frequency Amplifier&quot; presumably since 1964 has been produced by the Lianozovsky EMZ. The amplifier is designed to work together with a tape recorder, an electric player with a piezoelectric pickup, as well as with the high-frequency part of a homemade transistor radio receiver. The case could be made separately or used in common, with the listed devices. The maximum output power of the amplifier was 150 mW. The range of reproducible frequencies is 450 ... 3150 Hz. Depending on the size of the case, the lower indicator could be higher and start from 280 ... 300 Hz. Power supply of 9 volts from the &quot;Krona&quot; battery or from other elements connected in series, so that the total voltage is 9 volts.

When I was 10 years old, and this is 1964, then my older brother, he was then 22 years old, assembled such an amplifier from a set and made a case for it from red organic glass, 6 mm thick, with beautiful patterns cut out with a jigsaw for a loudspeaker. The amplifier was powered by &quot;Krona&quot;, which was located in the same case. I have not yet studied radio engineering, this stage I began at the age of 13, I didn’t think much, but when my brother was at work, I took this amplifier, turned it on with a variable resistor (volume control) with a switch and, taking the input with my hand, listened to the hum of alternating current 50 Hz (mains pickup). Through this hum, I heard some kind of hover-buzzers, tweeters, apparently transmitted through the power grid, and sometimes I heard the work of a broadcasting radio station (RV-44. Omsk), which was located 100 kilometers away. My joy knew no bounds and I walked down the street under the electric wires, trying to hear something new. I tried to walk under high-voltage lines, but there is only noise.

Set for the radio amateur `` Low frequency amplifier ''.