Link-11 (UHF)

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Link-11 | Link-11 (UHFUltra High Frequency (300-3000 MHz))

Link-11 (UHF)
Link-11 UHF.jpg
Frequencies 225 MHz,399.975 MHz
Frequency Range 225 MHz - 399.975 MHz
Mode NFM
Modulation PSK
Emission Designator
Bandwidth 30 kHz
Location Worldwide
Short Description This is the UHF band variant of Link-11, which is transmitted on a FM carrier. The FM-demodulated baseband is identical to the HF Link-11 waveform.
I/Q Raw Recording Download file
Audio Sample

This is the UHFUltra High Frequency (300-3000 MHz) band variant of Link-11, which is transmitted on a FMFrequency Modulation carrier. The FMFrequency Modulation-demodulated baseband is identical to the original Link-11 waveform used on MFMedium Frequency (300-3000 kHz) and HFHigh Frequency (3-30 MHz) bands. See the Link-11 page for in-depth details on the underlying waveform characteristics.


Link-11 UHFUltra High Frequency (300-3000 MHz) has many of the same characteristics as the original underlying Link-11 waveform, including the characteristic sound pattern. The UHFUltra High Frequency (300-3000 MHz) variant, which is FMFrequency Modulation-modulated, is about 30 kHzKiloHertz (kHz) 10^3 Hz wide in bandwidth. Each of the short ACK/ARQAutomatic Repeat reQuestAutomatic Repeat Query bursts are about 125ms long, with the data payload duration being variable.

When FMFrequency Modulation-demodulated, the waveform is equivalent to that of Link-11 on the MFMedium Frequency (300-3000 kHz) and HFHigh Frequency (3-30 MHz) bands.


  • This recording was captured being transmitted from a NATO AWACS aircraft on 339.550 MHzMegaHertz (MHz) 10^6 Hz over Poland on December 19, 2016. UHFUltra High Frequency (300-3000 MHz) use of Link-11 suggests line-of-sight operations. This was a FMFrequency Modulation-modulated Link-11 CLEW waveform.


For the UHFUltra High Frequency (300-3000 MHz) band, it is capable of tuning to any integral multiple of 25 kHzKiloHertz (kHz) 10^3 Hz from 225 MHzMegaHertz (MHz) 10^6 Hz to 399.975 MHzMegaHertz (MHz) 10^6 Hz.

Frequencies spotted at:

  • 339.550 MHzMegaHertz (MHz) 10^6 Hz

Video Examples[edit]

Decoding Software[edit]

It should be noted that these packages cannot decrypt Link-11 data

Professional Equipment/Software

Additional Links[edit]

Additional Images[edit]