Network tube radio receiver `` M-648 ''.
Tube radios.DomesticSince 1948, the M-648 radio receiver has been produced by the Krasin Moscow Radio Plant. Radio receiver `` M-648 '' Moscow, 6 lamp tubes (not counting the kenotron), 4 simultaneously operating circuits, 1948, superheterodyne powered from the mains. The design is horizontal, the box is finished with precious woods. A large luminous scale, graduated in kilohertz with the names of cities in the USSR, occupies the right half of the front side of the box. The tuning indicator is located in the upper part of the scale. Receiver control knobs are located under the scale. The left knob is the volume control with the mains switch, the second is the tone control, the third is the setting and the fourth is the range switch. To indicate the range on which the receiver is currently operating, in the lower right corner of the scale there is a window behind which the glowing inscriptions with the name of the ranges move. The left half of the front side of the receiver box, where the loudspeaker is placed, is covered with a silk decorative cloth. Antenna, grounding and adapter are connected from the rear of the receiver. The sockets of the adapter are automatic: inserting the plug of the adapter cord into the sockets stops the operation of the HF part of the receiver. Switching the mains voltage is carried out by moving the block on the cover of the power transformer. Unlike class 2 superheterodyne produced by our industry, the low-frequency amplifier of the M-648 radio receiver gives a high gain, which makes it possible to use an electromagnetic adapter for playing gramophone records. Frequency ranges: DV 150 ... 410 kHz, SV 525 ... 1500 kHz, KV survey 4 ... 12.3 MHz, KV-1 11.5 ... 12.4 MHz., KV-2 15. .16.1 MHz. Sensitivity in DV, SV ranges 150 ... 200 μV, KV 300 μV. Adjacent channel selectivity 26 dB. Rated output power 1.5 W. The range of reproducible frequencies is 100 ... 5000 Hz. Power consumption 75 watts.
