Subscriber loudspeaker '' PGR-3 ''.

Subscriber loudspeakers.DomesticSince 1945, the subscriber loudspeaker "PGR-3" has been produced by the Leningrad Union Telephone Plant No. 3 (later NPO Signal). There is not much information on this subscriber loudspeaker. The photographs show that the loudspeaker is piezoelectric. Since 1951, the same AG has been produced by the Tula plant Oktava, it was on the company's website in the list of products. More information in the instructions glued to the back of the case. Perhaps one of the varieties of the loudspeaker, and possibly the product of the "Oktava" plant in the last three photographs.