The Presto type Z radio receiver was manufactured by Towarzystwo Radiotechniczne Elektrit of Vilnius, which operated in 1925-1939, initially as a shop specialising in sales of imported radios and radio parts. Its profile was extended in 1927 by sales of radios of its own make. The company was established by Samuel and Hirsz Chwoles and Nachman Lewin. Due to the Jewish origin of the owners and of many members of the engineering staff (who were often discriminated against when applying for work in other factories, and employed in Elektrit for that very reason) on the wave of anti-Semitism that grew in Poland in the 1930s, the company’s products were often boycotted and considered “non-Christian”.
Presto is a seven-circuit radio receiver with four vacuum tubes. It has three wave bands: short, medium, and long. As the device has an untypical electrical system and is equipped with a small number of tubes, it is classified as a reflex system radio where one ABC1 tube serves a dual purpose; as a tube diode (rectifying tube detecting the signal) and as a triode (a signal amplifying tube). In this way, the radio signal received from the antenna is repeatedly processed in the radio’s system by the ABC1 tube, which replaces two other tubes. The radio is AC-powered (hence the letter “Z” in the type symbol). It has bandwidth adjustment, distance moderator, and tone adjustment.
The box of the Presto receiver has a horizontal layout. The chassis with electrical systems is enclosed in a wooden housing adorned with horizontal brass strips in the upper and lower part of the box, and on horizontal protruding strips of the fabric cover of the dynamic speaker (located on the left side of the front wall). On the right, in a square Bakelite frame, is a glass scale with the name of the company, the model, and the names of ranges and radio stations. Below it are two Bakelite knobs: a power and volume knob on the left, and a range and tuning switch on the right (long, medium, short wave and the gramophone function allowing the gramophone to be operated when connected). In the bottom part of the front housing there is a horizontal bar in the form of a semicircular, profiled plinth. At the back of the housing there is a masking wall, a power cord, connecting sockets for an external speaker, a gramophone, a ground wire, or an antenna.

Author: Filip Wróblewski