Yu. Borovsky. Pocket radio. V. Zhuravlev. Amateur subscriber loudspeakers for three programs. G. Kudelin. Semi-automatic for photo printing. V. Vlasenko. Sound reproducing installation. Yu. Pakhomov. Automatic adjustment of the recording level. V. Chekhut. Transistor-based tape reverberator. O. Streltsov. High-quality stereo amplifier LF. How to purchase books on radio engineering?