RDM-12
A mobile 12-channel frequency-modulated radio relay station designed for field radio relay communications at the operational-tactical and operational-command levels of command. It may be used as a terminal, repeater or node.
The set consists of two medium box trucks Praga V3S:
- Vehicle A for instrument placement
- vehicle B for transporting the power supply and antenna
RDM-12 allows:
- create 12 local telephone channels and 1 long distance service channel
- create 1 to 4 local telephone calls
- combine three telephone channels into four broadband channels for transmission of telegraph signals at a maximum speed of 16,000 Bd
- combine all 12 channels into one broadband channel for the transmission of telegraph signals at a maximum rate of 48 000 Bd
- assign one telegraph channel to any subscriber telephone channel using STT tone telegraphy equipment
- by means of a telephone classification device, any local telephone channel may be used for the transmission of a classified telephone call
The device was developed at the Tesla Hloubětín plant, with the participation of manufacturers from Czechoslovakia (Tesla Pardubice), but also from Hungary. It was introduced into the armament of the CSLA at the turn of the 1960s and 1970s. The NCO school (2nd Battalion 59th Regiment of Directional Stations) in Prague-Ruzyně in 1972 conducted training on a station with serial number 001, which allegedly dated from 1968. As of 31 December 1990, the CSLA Signal Corps had a total of 268 RDM-12 kits registered. Although they were scheduled to be retired during the 1990s, they are still in use in the armament of the Czech Armed Forces (e.g. at the 21st Tactical Air Force Base).
Technical and tactical data
Total weight:
- Vehicle A: ?
- Vehicle B: 10 660 kg
Crew: 5 (commander, 2 operators, 2 driver-machinists)
Frequency band:
- With 2 sub-bands, each with 600 fixed or continuously tunable channels:
-- in sub-band B from 120 to 239,8 MHz at 200 kHz spacing
-- in subband C from 240 to 479,6 MHz at 400 kHz spacing
Transmitted frequency band: 0.6 to 64 kHz
Subscriber telephone channel bandwidth: 0.3 to 3.4 kHz
Type of operation: frequency modulated telephony (F3)
Transmitter power:
- Basic: 5 W
- Full power: 50 W
Receiver sensitivity:
- in subrange B: 23 microV
- in subrange C: 16 microV
Line-of-sight range: 40 to 70 km
Total range: up to 400 km (using 7 to 9 repeater stations)
Power supply: mains (220 V / 50 Hz) or own power stations (vehicle B carries two EC 3 kVA)
1) Description of the exhibit displayed in the military museum in Lesany, September 2007
2) Burian, M., Rýc, J.: Historie spojovacího vojska, Prague 2007
3) Author's archive
4) M. Chalupa - memories
A mobile 12-channel frequency-modulated radio relay station designed for field radio relay communications at the operational-tactical and operational-command levels of command. It may be used as a terminal, repeater or node.
The set consists of two medium box trucks Praga V3S:
- Vehicle A for instrument placement
- vehicle B for transporting the power supply and antenna
RDM-12 allows:
- create 12 local telephone channels and 1 long distance service channel
- create 1 to 4 local telephone calls
- combine three telephone channels into four broadband channels for transmission of telegraph signals at a maximum speed of 16,000 Bd
- combine all 12 channels into one broadband channel for the transmission of telegraph signals at a maximum rate of 48 000 Bd
- assign one telegraph channel to any subscriber telephone channel using STT tone telegraphy equipment
- by means of a telephone classification device, any local telephone channel may be used for the transmission of a classified telephone call
The device was developed at the Tesla Hloubětín plant, with the participation of manufacturers from Czechoslovakia (Tesla Pardubice), but also from Hungary. It was introduced into the armament of the CSLA at the turn of the 1960s and 1970s. The NCO school (2nd Battalion 59th Regiment of Directional Stations) in Prague-Ruzyně in 1972 conducted training on a station with serial number 001, which allegedly dated from 1968. As of 31 December 1990, the CSLA Signal Corps had a total of 268 RDM-12 kits registered. Although they were scheduled to be retired during the 1990s, they are still in use in the armament of the Czech Armed Forces (e.g. at the 21st Tactical Air Force Base).
Technical and tactical data
Total weight:
- Vehicle A: ?
- Vehicle B: 10 660 kg
Crew: 5 (commander, 2 operators, 2 driver-machinists)
Frequency band:
- With 2 sub-bands, each with 600 fixed or continuously tunable channels:
-- in sub-band B from 120 to 239,8 MHz at 200 kHz spacing
-- in subband C from 240 to 479,6 MHz at 400 kHz spacing
Transmitted frequency band: 0.6 to 64 kHz
Subscriber telephone channel bandwidth: 0.3 to 3.4 kHz
Type of operation: frequency modulated telephony (F3)
Transmitter power:
- Basic: 5 W
- Full power: 50 W
Receiver sensitivity:
- in subrange B: 23 microV
- in subrange C: 16 microV
Line-of-sight range: 40 to 70 km
Total range: up to 400 km (using 7 to 9 repeater stations)
Power supply: mains (220 V / 50 Hz) or own power stations (vehicle B carries two EC 3 kVA)
1) Description of the exhibit displayed in the military museum in Lesany, September 2007
2) Burian, M., Rýc, J.: Historie spojovacího vojska, Prague 2007
3) Author's archive
4) M. Chalupa - memories
