Network tube radio receiver "ECHS-3" and "ECHS-4".
Tube radios.DomesticThe network tube radio "ECHS-3" and "ECHS-4" from the fall of 1933 and March 1935 produced the Moscow EMZ im. S. Ordzhonikidze. The ECHS-3 and ECHS-4 receivers are identical in principle, except that the ECHS-4 has a built-in loudspeaker, therefore its external design differs from the ECHS-3 model. The receivers are designed to be powered from an alternating current with a voltage of 110, 120 or 220 V. According to the scheme, these are regenerative direct amplification receivers of the 1-V-2 type with 3 tunable circuits. The output power of the LF amplifier is 0.8 ... 1 W. Wave range 200 .... 2000 meters, divided into 4 sub-bands. There is an adapter input for playing gramophone records by an external electric player. All parts of the receivers are mounted on a metal chassis attached to the bottom of the case with a removable back wall. Four control knobs are located on the front and side walls. The knobs for setting, volume and feedback are displayed in front, on the right side wall there is a range switch. On the back panel there are: a power switch, sockets for an antenna and grounding, an adapter and a loudspeaker. The "ECHS-3" receiver has two pairs of such sockets, for low-impedance and high-impedance loudspeakers, the "ECHS-4" receiver has one pair for an external low-impedance loudspeaker (its loudspeaker is switched off automatically when this is switched on). Over the years of production, the "ECHS-3" and "ECHS-4" radios have undergone at least 2 upgrades.
