Network tube radio receiver '' Riga T-689 ''.
Tube radios.DomesticSince 1946, the Riga T-689 tube network radio receiver has been produced by the Radiotekhnika plant in Riga. "Riga T-689" - is a 9-tube superheterodyne desktop-type radio receiver designed for receiving broadcasting stations and playing recordings from an external adapter, powered by 110, 127 and 220 V AC mains. The base radio receiver may have been the "Telefunken D-860WK" receiver. The abbreviation `` T-689 '' stands for: T - network, 6 - issue of 1946, 8 - the number of simultaneously operating configured HF, IF circuits, 9 - the total number of radio tubes. In addition to long, medium and short waves, the receiver has two extended HF sub-bands of 16 and 19 meters. An optical tuning indicator is used in the radio receiver. In addition to manual volume control, automatic gain control for RF cascades is also used. The receiver uses a four-stage tone control for high frequencies. The sensitivity of the receiver is approximately 100 µV. Adjacent channel selectivity is about 50 dB. Maximum output power 5W @ 10% THD. The band of reproducible sound frequencies is 45 ... 4000 Hz. A loudspeaker with increased acoustic characteristics is used in the radio receiver. The power consumed by the receiver from the network is 105 W. Receiver dimensions 585x415x315 mm. Weight 25 kg. The electrical circuits of the receivers of different years of release, and the receiver was produced until 1952, had minor differences.
