The TM-7 and TM-8 radio sets were produced from 1938 by the Alexander Radio Factory No. 3. The TM-7 and TM-8 radio sets are intended for use on broadcast radio stations. In a small number of receivers were implemented in retail. As to the receivers of broadcasting nodes, the following requirements were imposed on them: with good sensitivity and selectivity, to have enough power at the output to transmit over an air or cable line and excite the node's preamplifier. An output power of about 200 ... 250 milliwatts is sufficient for this. Since the receivers are designed to receive broadcasting stations in all points of the USSR, they must be full wave. By the time of the release of these receivers, the most suitable for their performance was the receiver "SVD-M". At its base, these receivers began to be produced. This explains the fact that both receivers, both in the design and construction, are almost identical with the receiver "SVD-M" and have approximately the same parameters. The main difference lies in the fact that they lack the last step of power amplification. Between themselves, they differ in that "TM-8" is designed to be powered from AC mains, and "TM-7" from batteries, so there is no rectifier unit in it. In addition, in order to save batteries, in the "TM-7" model circuit there is no optical setting indicator lamp 6E5, which is available in the "TM-8" receiver circuitry. The receivers are decorated in iron boxes, painted black on the outside, and on the inside with aluminum paint. The chassis is similar to the chassis of the '' SVD-M '' and is reinforced in cases on rubber shock absorbers. The top cover of the case opens and provides access to the top of the chassis. The back wall of the case is perforated (for ventilation). The control knobs are brought to the front side: this is a range switch, a tuning knob, a volume control and a timbre for high frequency. In the "TM-8" receiver, the last knob is also a power switch.On the back side are the antenna jacks, ground, the pickup, as well as the output jacks of the receiver. The output power of both receivers for a resistance of 600 ohms and with a 5% clear factor is 200 mW. The frequency converter is 445 kHz. The range of received radio frequencies and waves: A - 150 ... 400 kHz (2000 ... 750 m). B - 540 ... 1500 kHz (556 ... 200 m). G - 3500 ... 9000 kHz (85.7 ... 33.3 m). D - 8.2 ... 18 MHz (36.6 ... 16.7 m). High frequency sensitivity with 30% modulation and 0.02 watt output power, in all ranges around 50 µV. LF sensitivity (voltage on the pickup jacks) at a nominal output power of 200 mV. Attenuation of the signal when the receiver is detuned by 10 kHz: on the A, B bands by 10 times, D, D by 5 times. The attenuation of the mirror noise on the bands A, B in 1000 times, G, D in 55 times. The frequency response at a low frequency from the pickup input to the output of the radio receiver is straightforward in the range of 60 to 6000 Hz. Receiver "TM-8" consumes 75 watts. Receiver "TM-7" requires 6.5 volts on the heat, with a current of 2.65 a, and an anode of 240 in, with a current of 75 mA.