IARU Region 2 Monitoring System

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The IARU MS is often asked for audio samples that can be used to help identify unknown intruder signals heard in the Amateur bands. 

Below are links to audio samples in WAV format of various analog and digital radio signals which might be encountered in the Amateur Radio bands. Listening to these samples and comparing them with the sound of an unidentified signal on the air, you can often identify the unknown signal, although there is no guarantee that you will find an exact match in these collections. Due to the complexity of some new signals, however, even an "exact match" can be misleading, but the examples provided will at least help you to tell the differences between certain similar signals and may provide the key you need to identify an unfamiliar signal.

Credit for this impressive collection: IARU R1 Monitoring System.

Local Intruders
Local QRM

Plasma TV on 3.5 MHz (USB)
Plasma TV on 3.5 MHz (AM)
Plasma TV on standby condition on 3.5 MHz
TV switching power supply on 14 MHz
Small LCD TV on 7 MHz
Large LCD TV on 3515 kHz (USB)
TFT Computer monitor on 21377 kHz
Computer monitor on 18.1 MHz
PLC noise on 50110 kHz
TELEFAX device made in Thailand
LED power supply disturbing 12 - 15 MHz
LED power supply disturbing 7 - 21 MHz
Pasture fence on 3.5 MHz
DSL broadband modem on 21 MHz

PSK Systems
Serial and Parallel modems
Frequency Division Multiplex (FDM)

Arcotel MAHRS/EADS serial modem 2k4 Bd PSK 8 on 3507 kHz
Codan 9001 16 x 75 Bd QPSK - MFA Cairo on 14056.5 kHz
Chinese MIL 18 tone FDM 18 x 44.44 Bd QPSK
Chinese PRC-FSK4 4 x 100 Bd on 14062 kHz
Chinese MIL PRC4+4 8 x 75 Bd QPSK Idling
Chinese MIL PRC4+4 8 x 75 Bd QPSK Traffic
Chinese MIL PRC16 16 x 75 Bd PSK2
Russian MIL CIS12 12 x 120 Bd AT3004D
Russian MIL MPSK16 (+1) FDM 16 x 75 Bd PSK
Turkish MIL Stanag 4285 PSK8 on 10112 kHz legal operation
MIL188-110A PSK8 600 Bps on 7080.8 kHz
MIL188-110A QPSK hybrid modem on 14002 kHz ISR Navy system
Link11 CLEW MIL system
Link11 SLEW serial modem 2k4 PSK8 MIL system
Siemens CHP200 on 10131.6 kHz
Clover 2000 8 x 62.5 Bd BPSK/QPSK on 7001.5 kHz
Italian MIL VFT Brescia on 29699 kHz
OFDM 60 tones Russian MIL on 7000.8 kHz
OFDM 72 tones on 14035.8 kHz
OFDM 128 tones on 14277 kHz
OFDM 112 tones burst mode on 14 MHz
OFDM 73 burst mode on 14350 kHz
RFSM2000 serial modem 2000 Bd PSK8
Frequency hopper

FSK Systems
Frequency Shift Keying (F1B/F7B)

Codan Selcall
ARQ-E3 on 10104 kHz
Portuguese mysterious F1B bursts 28100 kHz 51 Bd
ALE MIL188-141A
CIS printer 75 Bd 250 Hz shift
CIS printer 81-81 Bd 250 Hz shift
Russian (Moscow) F1B 100 Bd 1000 Hz shift REA4 on 7117.0 kHz
Russian Yakhta synchronous FSK 100 Bd 150 Hz
UK CLANSMAN system 300 Bd 850 Hz
North Korean DPRK FSK600 on 10133.3 kHz diplomatic traffic
North Korean DPRK FSK1200 on 28149.2 kHz diplomatic traffic
Illegal Dataplex from Global Link (China) on 7086.5 kHz
Racal Skyfax MSM1250 10 x 125 Bd on 10126 kHz
Spanish mysterious FSK on 28245.82 kHz
GPS buoy FSK 51 Bd bursts on 28100 kHz
Moroccan Datawell buoy FSK 81.9 Bd on 29525 kHz
Russian (Moscow) REA4 with CW Id on 7018 kHz

Multitone Systems (F7D)

Russian CROWD36 CIS36 36 tones
CIS Mazielka Selcall multitone
Chinese multitone on 14321 kHz

Radar Systems (FMCW/FMOP)

Chinese OTH Radar 43 sweeps/sec on 7 MHz
Chinese OTH Radar 66.66 sweeps/sec bursts
Chinese OTH Radar 10 sweeps/sec on 7 MHz broadband 160 kHz wide
Cypriot OTH Radar 50 sweeps/sec
Cypriot OTH Radar 25 sweeps/sec
Cypriot OTH Radar 12.5 sweeps/sec
Turkish OTH Radar 50 sweeps/sec
OTH Radar on 80m in Region 3
OTH Radar made by DK2OM
Russian old OTH Radar ABM-2
Russian OTH Radar 10 sweeps/sec
Russian OTH Radar Contayner 50 sweeps/sec
Iranian old OTH Radar on 14 and 21 MHz
Iranian later OTH Radar on 14 and 21 MHz
Iranian Radar on 28 - 29.7 MHz
Iranian Radar on 28 MHz AM
Iranian Radar 150/313 sweeps/sec AM
French OTH Radar “Nostradamus” 33 sweeps/sec on 14 MHz
French Burst OTH Radar 6 sweeps/sec on 14 MHz
Australian HF Radar "Tiger" on 10 MHz
Superdarn ionospheric radar
Codar short range HF Radar 2 sweeps/sec
Codar like HF Radar from Far East 2.6 sweeps/sec
USA new HF Radar
Ocean Surface Radar
Chinese coastal Radar 2.6 sweeps/sec
Australian JORN OTH Radar
Indian CODAR 2 sweeps/sec on 14075 - 14125 kHz
Russian coastal Radar “Sunflower” 43 sweeps/sec on 3540 - 3600 kHz
Russian OTH Radar 87 sweeps/sec on 3600 kHz

Beacons and buoys

Fishery buoy Id “AH” on 28191 kHz
Fishery buoy Id “Y” on 28356 kHz
Fishery buoy Id “MA” on 28091 kHz
Gabonese carrier and dots on 28345 kHz LSB/USB
Single letter beacons on 7039 kHz
Kyrgyzstan (Bishkek) Beacon “V” A1A (CW) on 7027.5
L9CC and CP17 on 7052 kHz
Kazakhstan Beacon “V” on 7091.5 kHz
Russian MIL channelmarker on 3756 kHz AM
Russian buzzer on 7 MHz AM

Navigation Systems

Russian Navy BRAS-3/RS-10 hyperbolic navigation system on 3756 kHz AM
Russian Navy BRAS-3/RS-10 hyperbolic navigation system on 1812 kHz DSB


TV image carrier on 50105 kHz

Broadcast intrusions (AM)

Chinese music jammer on 18160 kHz AM
Chinese music jammer on 14260 kHz AM
Radio Eritrea National Anthem on 7 MHz
Radio Ethiopia National Anthem on 7 MHz
Voice of Russia on 7200 kHz
Sound of Hope and Chinese jammer on 18080 kHz

Voice encryption

Spanish fishery CRY2001 voice scrambler on 10150 kHz
Russian MIL Yakhta voice scrambler on 28347 kHz

Unknown and mysterious systems
Clandestine emissions

Mysterious “V” from Israel on 7 MHz
Ukrainian secret service on 10120 kHz AM every Wed at 08:43Z
Mysterious siren from Vietnam on 18112.5 kHz
Ukrainian secret service on 14280 kHz AM every Wed at 10:00Z faded out
Chinese moo noise on 21 MHz A3E
Chinese chirpy noise on 21000 - 21200 kHz
Chinese multitone on 21 MHz A3E
Mysterious oscillation from the Caribbean area on 28002 kHz

Illegal voice traffic

Nigerian fishermen traffic on 21002.2 kHz USB
Sri Lanka fishermen traffic on 14 MHz USB
Indian Ocean traffic on 14001.5 kHz USB
Tamil intruders traffic on 14 MHz USB
Galician fishery traffic on 14345 kHz USB
Spanish fishery traffic on 21410 kHz USB
Spanish fishery traffic on 14325 kHz USB
Spanish fishery traffic on 7 MHz USB
Russian voice taxi traffic on 28145 kHz FM
Russian (Moscow) taxi traffic on 21404.2 kHz FM
Russian voice taxi traffic on 29015 kHz FM
Sudanese embassy traffic on 21 MHz USB
Indonesian net on 7 MHz USB
Indonesian net on 10147 kHz LSB
Indonesian pirates on 7020 kHz LSB
Far East carrier and grunt on 21000 kHz A3E

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