Radioteknicheskaya Systema Dalney Navigatsii (RSDN-20)

Radioteknicheskaya Sistema Dal'ney Navigatsii (RSDN-20)

Frequencies	11.91 kHz,12.09 kHz,12.65 kHz,14.88 kHz,12.04 kHz
Frequency Range	11.91 kHz - 14.88 kHz
Mode	CW
Modulation	—
ACF	—
Emission Designator	—
Bandwidth	20 Hz
Location	Russia
Short Description	RSDN-20, also known as Alpha, is a Russian hyperbolic radio navigation system. Presumed to be used for Russian ships, submarines and aircraft in the northern hemisphere, possibly worldwide.
I/Q Raw Recording	—
Audio Sample

Radioteknicheskaya Sistema Dal'ney Navigatsii, also known as RSDN-20 and with the designation Alpha, is a Russian hyperbolic radio navigation system. Presumed to be used for Russian ships, submarines and aircraft in the northern hemisphere, possibly worldwide. These transmissions are among the lowest-frequency man made transmissions in the world. The Russian name means "Radiotechnical long-range navigation system". The RSDN-20 system is said to have a range of 10000 km and a position error of 2.5 to 7 km.

RSDN-20 transmitters are located in Novosibirsk, Krasnodar, and Khabarovsk in Russia. Two other transmitters exist in Revda and Seyda, but they are no longer operational.

Frequencies

The three main frequencies of RSDN-20 are:

• F1: 11.904761 kHzKiloHertz (kHz) 10^3 Hz
  
• F2: 12.648809 kHzKiloHertz (kHz) 10^3 Hz
  
• F3: 14.880952 kHzKiloHertz (kHz) 10^3 Hz
  

Known alternative frequencies are:

• F3p: 14.881091 kHzKiloHertz (kHz) 10^3 Hz
  
• F4: 12.090773 kHzKiloHertz (kHz) 10^3 Hz
  
• F5: 12.044270 kHzKiloHertz (kHz) 10^3 Hz
  
• F6: 12.500000 kHzKiloHertz (kHz) 10^3 Hz
  
• F7: 13.281250 kHzKiloHertz (kHz) 10^3 Hz
  
• F8: 15.625000 kHzKiloHertz (kHz) 10^3 Hz
  
• Fx: 12.700000 kHzKiloHertz (kHz) 10^3 Hz
  
  

  Video Examples

• ALPHA RSDN 20/Part-2/Revda-test transmitting
• ALPHA RSDN-20 / Part 3/ November 2010
• ALPHA RSDN-20/Part-1/Usually transmitting
• Russian Alpha navigation signals on VLF received in Romania
• Russian VLF Alpha RSDN-20 Navigation System | Signal Phantom
• Alpha (RSDN-20) 14,88 kHz VLF navigation
• RSDN-20/Alpha 11,9 kHz russian navigation

Additional Links

• THE RUSSIAN VLF NAVAID SYSTEM, ALPHA, RSDN-20, By Trond JACOBSEN, Halden (NORWAY)

• Wikipedia: Alpha (navigation)

Additional Images

Faint sample of the three main frequencies of RSDN-20 "Alpha" received in 2026. USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) tuned to 11.7 kHzKiloHertz (kHz) 10^3 Hz with about 3.3 kHzKiloHertz (kHz) 10^3 Hz bandwidth to include all frequencies.