Overview

The R-105D Astra-3 (Р-105Д Астра-3) is a VHF portable radio transceiver developed and used by the Soviet military. The Astra series, developed in the late 1940s, was intended to replace the A-7 series radio sets, with the R-105D entering service in 1952. The R-105D was eventually superseded by the R-105M Parus-3 (P-105M Парус-3) in 1967.

Development History

The development of the Astra series began in the late 1940s at the Scientific Research and Test Institute for Communications of the Army (NIIIS SV). The goal was to modernize the Soviet military’s communication capabilities by replacing the outdated A-7 series radio sets. The prototypes of the Astra series were tested and subsequently entered service with the Soviet armed forces in 1952.

Technical Specifications

The R-105D is an FM, superheterodyne radio transceiver based on valve circuitry. Key technical specifications are as follows:

• Frequency Range:
  • R-105D (Р-105Д): 36.0 to 46.1 MHz (used by motorized infantry and tank troops)
  • R-108D (P-108Д): 28.0 to 36.5 MHz (version used by artillery units)
  • R-109D (P-109Д): 21.5 to 28.5 MHz (HF band variant used by the air defense forces)
• Receiver Sensitivity: Better than 1.5 μV at a signal-to-noise ratio of 10:1
• Transmitter Output Power: 1 Watt
• Power Source: Two nickel-cadmium batteries (2NKN-24 or 2KN-32) with a total voltage of 4.8 V. HT supply to the anode circuits is provided by a built-in vibration transducer.
• Battery Endurance: Continuous operation time at a 3:1 reception/transmission ratio ranges from 12 to 17.5 hours, depending on the battery type.
• Antenna: Flexible whip antenna 1.5 m high (Kulikov’s pin type) with extensions up to 2.7 m. External antennas can also be used.
• Range: 10 km with a short whip antenna, and 30-40 km with more complex antennas.
• Operating Temperature Range: -40 to +50 °C
• Dimensions of Transceiver: 365 × 385 × 230 mm
• Weight: 21 kg

Operational Use

The R-105D was widely used by various units within the Soviet military:

• Motorized Infantry and Tank Troops: Utilized the R-105D variant for reliable battlefield communication.
• Artillery Units: Employed the R-108D variant, operating in the 28.0 to 36.5 MHz frequency range.
• Air Defense Forces: Used the R-109D variant, operating in the 21.5 to 28.5 MHz HF band.

Legacy

The introduction of the R-105D marked a significant advancement in Soviet military communications, offering improved reliability and range compared to its predecessors. The continued modernization efforts led to the development of the R-105M Parus-3, ensuring the Soviet armed forces maintained robust communication capabilities throughout the Cold War era.

References

• “Развитие отечественной военной радиосвязи”. www.computer-museum.ru. Retrieved 18 June 2018.
• “Р-105Д”. www.radioscanner.ru. Retrieved 18 June 2018.