Signal Identification Guide

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This wiki is intended to help identify radio signals through example sounds and waterfall images. Most signals are received and recorded using a software defined radio such as the RTL-SDR, HackRF, BladeRF, Funcube Dongle, USRP or others.

Anyone can edit this wiki, so if you see missing or wrong information please feel free to correct it by clicking the 'edit' button at the stop of the signals page. When doing an edit you will be asked to answer a very simple spam prevention question which will appear at the top of the screen after clicking on Save page.

You can also discuss the signals by using the discussion tab at the top of every page, or just by using the comments box at the bottom of this page.

If you would like to contribute an example signal, please contact me at rtlsdrblog__AT__gmail__DOT__com and send a waterfall image, sound or small IQ sample and any information about the signal that you have. Note that it will probably take me 1 - 3 months to get to your signal. If you want to add a signal yourself please consult the instructions here - Adding An Example Signal. Don't worry too much if you mess up the wiki syntax, i'll eventually patrol all the pages and fix them up if something is wrong.

Known Reference Signals

Signal Type Description Frequency Mode Bandwidth Location Sample Audio Waterfall Image
29B6 OTH Radar Sounder This is an Over The Horizon Radar Sounder signal from the 29B6 OTH Radar. It is used to check frequencies that are not in use. It commonly overlaps Amateur and broadcast shortwave bands. 9.2 MHz9,200,000 Hz
9,200 kHz
, 19.745 MHz19,745,000 Hz
19,745 kHz
USB 13,620 Hz13.62 kHz
0.0136 MHz
Russia Ss (2014-12-14 at 01.58.43).png
AFSK Paging Link It is easier to transmit the FSK pager signal to the transmitter site as AFSK. It is changed to POCSAG format when re-transmitted. 72 MHz72,000,000 Hz
72,000 kHz
, 75 MHz75,000,000 Hz
75,000 kHz
NFM 9,000 Hz9 kHz
0.009 MHz
Worldwide AFSKPaging Waterfall.png
AMTOR/SITOR SITOR stands for Simplex Teletype Over Radio. Usually used to transmit maritime short messages, weather forecasts and warnings. AMTOR is the same but is used by amateur radio operators. 3 MHz3,000,000 Hz
3,000 kHz
USB 0 Hz0 kHz
0 MHz
Worldwide NO Waterfall.jpg
ATSC Broadcast Advanced Television Systems Committee Television. 8VSB Modulation 6,000,000 Hz6,000 kHz
6 MHz
Worldwide No Audio File ATSCthumb.jpg
Aircraft Communications Addressing and Reporting System (ACARS) Short messages sent to and from aircraft. 129.125 MHz129,125,000 Hz
129,125 kHz
, 130.45 MHz130,450,000 Hz
130,450 kHz
, 131.125 MHz131,125,000 Hz
131,125 kHz
, 131.45 MHz131,450,000 Hz
131,450 kHz
, 131.475 MHz131,475,000 Hz
131,475 kHz
, 131.725 MHz131,725,000 Hz
131,725 kHz
, 136.7 MHz136,700,000 Hz
136,700 kHz
, 136.9 MHz136,900,000 Hz
136,900 kHz
, 136.85 MHz136,850,000 Hz
136,850 kHz
, 136.75 MHz136,750,000 Hz
136,750 kHz
, 131.85 MHz131,850,000 Hz
131,850 kHz
, 131.55 MHz131,550,000 Hz
131,550 kHz
, 130.025 MHz130,025,000 Hz
130,025 kHz
, 130.425 MHz130,425,000 Hz
130,425 kHz
, 131.525 MHz131,525,000 Hz
131,525 kHz
, 136.8 MHz136,800,000 Hz
136,800 kHz
AM 5,000 Hz5 kHz
0.005 MHz
Worldwide ACARS waterfall.png
Amplitude Modulation (AM) Long range commercial broadcast and international radio. Also used for aviation communications. 0.153 MHz153,000 Hz
153 kHz
, 0.279 MHz279,000 Hz
279 kHz
, 0.531 MHz531,000 Hz
531 kHz
, 1.611 MHz1,611,000 Hz
1,611 kHz
, 0.54 MHz540,000 Hz
540 kHz
, 1.61 MHz1,610,000 Hz
1,610 kHz
, 2.3 MHz2,300,000 Hz
2,300 kHz
, 108 MHz108,000,000 Hz
108,000 kHz
, 137 MHz137,000,000 Hz
137,000 kHz
, 26.1 MHz26,100,000 Hz
26,100 kHz
AM 10,000 Hz10 kHz
0.01 MHz
Worldwide AM Waterfall.jpg
Autocab This is an example of the Autocab Media Data Terminals used by cab companies all over the world. Also this could be the answer for unknown signal Unknown 469. 163.375 MHz163,375,000 Hz
163,375 kHz
NFM 12,500,000 Hz12,500 kHz
12.5 MHz
UK Autocab.png
Automatic Dependent Surveillance-Broadcast (ADS-B) Used by aircraft as an artificial radar. Broadcasts their latitude, longitude and altitude from GPS information. 1,090 MHz1,090,000,000 Hz
1,090,000 kHz
, 978 MHz978,000,000 Hz
978,000 kHz
None 50,000 Hz50 kHz
0.05 MHz
, 1,300,000 Hz1,300 kHz
1.3 MHz
Worldwide ADSB Waterfall.png
Automatic Identification System (AIS) Used by ships to broadcast position and vessel information. 161.975 MHz161,975,000 Hz
161,975 kHz
, 162.025 MHz162,025,000 Hz
162,025 kHz
NFM 25,000 Hz25 kHz
0.025 MHz
Worldwide AIS Waterfall.jpg
Automatic Packet Reporting System (APRS) Packet system for real time data communications. Used by hams for location reporting, weather stations etc. 144.39 MHz144,390,000 Hz
144,390 kHz
, 144.575 MHz144,575,000 Hz
144,575 kHz
, 144.66 MHz144,660,000 Hz
144,660 kHz
, 144.93 MHz144,930,000 Hz
144,930 kHz
, 145.57 MHz145,570,000 Hz
145,570 kHz
, 145.525 MHz145,525,000 Hz
145,525 kHz
, 144.8 MHz144,800,000 Hz
144,800 kHz
, 145.175 MHz145,175,000 Hz
145,175 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
Worldwide AFSK1200 Waterfall.png
Automatic Picture Transmission (APT) Used to by the NOAA weather satellites and some Russian weather satellites to transmit satellite weather photos. 137.62 MHz137,620,000 Hz
137,620 kHz
, 137.913 MHz137,912,500 Hz
137,912.5 kHz
, 137.1 MHz137,100,000 Hz
137,100 kHz
, 137.85 MHz137,850,000 Hz
137,850 kHz
, 137.3 MHz137,300,000 Hz
137,300 kHz
NFM 30,000 Hz30 kHz
0.03 MHz
Worldwide NOAAAPT Waterfall.png
Baby Monitor Wireless baby monitors often transmit NFM audio in the clear. 40 MHz40,000,000 Hz
40,000 kHz
, 49.5 MHz49,500,000 Hz
49,500 kHz
, 50 MHz50,000,000 Hz
50,000 kHz
, 27 MHz27,000,000 Hz
27,000 kHz
, 864 MHz864,000,000 Hz
864,000 kHz
NFM 15,000 Hz15 kHz
0.015 MHz
Worldwide No Audio File BabyMonitor Waterfall.png
Binary Interchange of Information and Signaling (BIIS) European Trunked Radio Standard, 1200 bps. Can transmit both voice and data 446 MHz446,000,000 Hz
446,000 kHz
NFM 2,000 Hz2 kHz
0.002 MHz
Europe BIISthumb.png
Binary Phase Shift Keying (BPSK31) A digital amateur radio mode based on Phase Shift Keying (PSK) modulation. 7.035 MHz7,035,000 Hz
7,035 kHz
, 7.04 MHz7,040,000 Hz
7,040 kHz
, 10.142 MHz10,142,000 Hz
10,142 kHz
, 14.07 MHz14,070,000 Hz
14,070 kHz
, 21.08 MHz21,080,000 Hz
21,080 kHz
, 50.29 MHz50,290,000 Hz
50,290 kHz
, 144.144 MHz144,144,000 Hz
144,144 kHz
, 222.07 MHz222,070,000 Hz
222,070 kHz
, 432.2 MHz432,200,000 Hz
432,200 kHz
, 909 MHz909,000,000 Hz
909,000 kHz
, 1.838 MHz1,838,000 Hz
1,838 kHz
, 3.58 MHz3,580,000 Hz
3,580 kHz
, 18.1 MHz18,100,000 Hz
18,100 kHz
, 24.92 MHz24,920,000 Hz
24,920 kHz
, 28.12 MHz28,120,000 Hz
28,120 kHz
SSB 31 Hz0.031 kHz
3.1e-5 MHz
Worldwide BPSK31 Waterfall.png
CODAR Coastal Ocean Dynamics Applications Radar 13.5 MHz13,500,000 Hz
13,500 kHz
, 3 MHz3,000,000 Hz
3,000 kHz
, 50 MHz50,000,000 Hz
50,000 kHz
, 12.92 MHz12,920,000 Hz
12,920 kHz
, 4.465 MHz4,465,000 Hz
4,465 kHz
, 12.47 MHz12,470,000 Hz
12,470 kHz
USB 50,000 Hz50 kHz
0.05 MHz
Worldwide CODARthumbnail.png
California Smart-Meter This is a signal from a Californian Electricity 'Smart Meter'. Each house is now fitted with one of these, and they are strong - typically 50dB above the atmospheric noise level. 928 MHz928,000,000 Hz
928,000 kHz
, 902 MHz902,000,000 Hz
902,000 kHz
15,000 Hz15 kHz
0.015 MHz
USA No Audio File Open-Way-Centron Smart-Meter Waterfall.gif
Cuban Numbers Station HM01 Numbers stations are thought to transmit encoded information for various spy agencies around the world. They are recognized by a voice reading a sequence of numbers or words. This is a Cuban Numbers Station which has a data portion and a voice portion. 11.53 MHz11,530,000 Hz
11,530 kHz
, 16.18 MHz16,180,000 Hz
16,180 kHz
, 9.24 MHz9,240,000 Hz
9,240 kHz
AM 10,000 Hz10 kHz
0.01 MHz
Worldwide HM01 Waterfall.png
D-STAR Digital voice protocol used by ham radio. Is sometimes routed over the internet for international communications. 145.67 MHz145,670,000 Hz
145,670 kHz
NFM 6,250 Hz6.25 kHz
0.00625 MHz
Worldwide DStar Waterfall.jpg
Digital Audio Broadcasting (DAB) A type of digital broadcast radio signal, containing multiple digital radio stations in the signal. 239.2 MHz239,200,000 Hz
239,200 kHz
, 174.928 MHz174,928,000 Hz
174,928 kHz
, 1,452.96 MHz1,452,960,000 Hz
1,452,960 kHz
, 1,490.625 MHz1,490,625,000 Hz
1,490,625 kHz
None 1,537,000 Hz1,537 kHz
1.537 MHz
Worldwide No Audio File DAB Waterfall.jpg
Digital Audio Broadcasting + (DAB+) A type of digital broadcast radio signal, containing multiple digital radio stations in the signal. Here transmitted on channel 7D. 194.064 MHz194,064,000 Hz
194,064 kHz
None 1,500,000 Hz1,500 kHz
1.5 MHz
Switzerland No Audio File 193MHz Waterfall.png
Digital Radio Mondiale (DRM) A form of international digital shortwave radio. A digital alternative to AM shortwave radio. 1 MHz1,000,000 Hz
1,000 kHz
, 22 MHz22,000,000 Hz
22,000 kHz
USB 10,000 Hz10 kHz
0.01 MHz
Worldwide DRM Waterfall.png
Distributed Power Unit (DPU) Distributed power refers to the placing of an extra locomotive at an intermediate point in the middle section of a train. This locomotive unit is remotely controlled from the lead locomotive, and greatly increases both the pulling and stopping power of longer trains. 457.925 MHz457,925,000 Hz
457,925 kHz
NFM 0 Hz0 kHz
0 MHz
Seattle Distributed Power Unit (DPU).png
EDACS96 Radio trunking control channel. 860 MHz860,000,000 Hz
860,000 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
Worldwide EDACS96 Waterfall.png
Emergency Action Message (EAM) This is a system used by the US Military to direct nuclear capable forces to execute an operation. This sound file was recorded at 11.175 KHz (Female Voice, Mainsail to Skyking) on 05-20-14 at 0035 UTC. 0.0112 MHz11,175 Hz
11.175 kHz
USB 0 Hz0 kHz
0 MHz
Seattle EAM Waterfall.png
End of Train (EOT) Transmits train telemetry such as brake status and accidental seperation information to the head locomotive. 457.938 MHz457,937,500 Hz
457,937.5 kHz
NFM 0 Hz0 kHz
0 MHz
Seattle EOT Waterfall.png
European Radio Messaging System (ERMES) A European radio paging system. 169 MHz169,000,000 Hz
169,000 kHz
NFM 0 Hz0 kHz
0 MHz
Europe Ermes desktop.jpg
FLEX Pager digital signal. 169 MHz169,000,000 Hz
169,000 kHz
, 929 MHz929,000,000 Hz
929,000 kHz
, 929.612 MHz929,612,000 Hz
929,612 kHz
, 929.662 MHz929,662,000 Hz
929,662 kHz
, 929.937 MHz929,937,000 Hz
929,937 kHz
, 929.362 MHz929,362,000 Hz
929,362 kHz
, 929.387 MHz929,387,000 Hz
929,387 kHz
, 929.538 MHz929,538,000 Hz
929,538 kHz
NFM 5,000 Hz5 kHz
0.005 MHz
Worldwide FLEX.jpg
FUNcube-1 Telemetry The Funcube-1 is a Cubesat amateur radio satellite. 145.935 MHz145,935,000 Hz
145,935 kHz
USB 2,000 Hz2 kHz
0.002 MHz
Worldwide Funcube1 Waterfall.jpg
GMDSS Digital Selective Calling 2.188 MHz2,187,500 Hz
2,187.5 kHz
, 4.208 MHz4,207,500 Hz
4,207.5 kHz
, 6.312 MHz6,312,000 Hz
6,312 kHz
, 8.415 MHz8,414,500 Hz
8,414.5 kHz
, 12.577 MHz12,577,000 Hz
12,577 kHz
, 16.805 MHz16,804,500 Hz
16,804.5 kHz
FSK 3,000 Hz3 kHz
0.003 MHz
Worldwide Dsc waterfall.jpg
GSM Downlink (Non-Hopping) GSM Cell Phone Downlink (Non Hopping Signal). Audio sample used NFM mode. 900 MHz900,000,000 Hz
900,000 kHz
, 450 MHz450,000,000 Hz
450,000 kHz
, 850 MHz850,000,000 Hz
850,000 kHz
, 1,800 MHz1,800,000,000 Hz
1,800,000 kHz
None 200,000 Hz200 kHz
0.2 MHz
Worldwide GSMNonHopping Waterfall.png
GSM Hopping GSM hopping cell phone signal. 900 MHz900,000,000 Hz
900,000 kHz
, 450 MHz450,000,000 Hz
450,000 kHz
, 850 MHz850,000,000 Hz
850,000 kHz
, 1,800 MHz1,800,000,000 Hz
1,800,000 kHz
None 200,000 Hz200 kHz
0.2 MHz
Worldwide No Audio File GSMHopping Waterfall.jpg
GSM Uplink Initial GSM connection sent from a cell phone. 900 MHz900,000,000 Hz
900,000 kHz
, 450 MHz450,000,000 Hz
450,000 kHz
, 850 MHz850,000,000 Hz
850,000 kHz
, 1,800 MHz1,800,000,000 Hz
1,800,000 kHz
None 200,000 Hz200 kHz
0.2 MHz
Worldwide No Audio File GSMUplink Waterfall.png
High Frequency Data Link (HFDL) An Aircraft Communications Addressing and Reporting System (ACARS) data link that aircraft use to communicate short messages over long distances using HF signals. 2.9 MHz2,900,000 Hz
2,900 kHz
, 22 MHz22,000,000 Hz
22,000 kHz
USB 2,800 Hz2.8 kHz
0.0028 MHz
Worldwide HFDL Waterfall.png
ILS Marker Beacon Used by aircraft for Instrument Landing Systems, transmitted by an upward-facing directive antenna at known distances along the approach path. 75 MHz75,000,000 Hz
75,000 kHz
AM 3,000 Hz3 kHz
0.003 MHz
Worldwide LOM Waterfall.png
ISM Band Power Meter A wireless electricity power monitor. 433 MHz433,000,000 Hz
433,000 kHz
AM 20,000 Hz20 kHz
0.02 MHz
Worldwide ISMBandPowerMeter Waterfall.png
ISM Band Weather sensor Data returned from a consumer weather sensor using the AlectoV1 protocol. 433 MHz433,000,000 Hz
433,000 kHz
AM 4,400 Hz4.4 kHz
0.0044 MHz
Worldwide Alecto wx.png
Integrated Digital Enhanced Network (IDEN) A technology developed by Motorola. It is a type of trunked radio with cellular phone benefits. 154.463 MHz154,463,000 Hz
154,463 kHz
NFM 18,540 Hz18.54 kHz
0.0185 MHz
Worldwide No Audio File IDEN Waterfall.jpg
Ionosonde An Ionosonde is a radar that examines the Ionosphere by sweeping the HF band and receiving the echos 1 MHz1,000,000 Hz
1,000 kHz
, 40 MHz40,000,000 Hz
40,000 kHz
, 12 MHz12,000,000 Hz
12,000 kHz
, 1.6 MHz1,600,000 Hz
1,600 kHz
USB 2,500 Hz2.5 kHz
0.0025 MHz
Worldwide Ionosondethumb.jpg
JT65a Signal often spotted on Sunday between morning between the 8 and 14th hour of the day. 21.07 MHz21,070,000 Hz
21,070 kHz
, 27.08 MHz27,080,000 Hz
27,080 kHz
, 24.92 MHz24,920,000 Hz
24,920 kHz
USB 200 Hz0.2 kHz
2.0e-4 MHz
Worldwide JT65A Waterfall.png
Japanese Slot Machine (XSL) Known as the Japanese Slot Machine. Thought to be data originating from the Japanese Navy. 3 MHz3,000,000 Hz
3,000 kHz
, 9 MHz9,000,000 Hz
9,000 kHz
USB? 2,000 Hz2 kHz
0.002 MHz
Worldwide JSM Waterfall.png
LTE Network Long Term Evolution Network 739 MHz739,000,000 Hz
739,000 kHz
None 9,000,000 Hz9,000 kHz
9 MHz
Worldwide No Audio File LTEthumb.jpg
LoJack LoJack is a vehicle tracking system that allows vehicles to be tracked by police, with the aim of recovering them in case of theft via a small radio transceiver clandestinely installed in a vehicle. 173.075 MHz173,075,000 Hz
173,075 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
USA LoJack Signal.png
Logic Trunked Radio Control Control channel for a logic trunked radio system. 164.3 MHz164,300,000 Hz
164,300 kHz
NFM 0 Hz0 kHz
0 MHz
Austria LogicTrunkedRadio Waterfall.jpg
MOBITEX A packet-switched data network used often by public safety.  ???  ??? NO Waterfall.jpg
MPT1327 Radio trunking control channel. 420 MHz420,000,000 Hz
420,000 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
Worldwide MPT1327 Waterfall.png
MotoTRBO Motorola digital voice protocol. 860 MHz860,000,000 Hz
860,000 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
Worldwide DMRMOTOTRBO Waterfall.png
Motorola 2F1D Radio trunking control channel. 860 MHz860,000,000 Hz
860,000 kHz
NFM 8,000 Hz8 kHz
0.008 MHz
Worldwide Motorola2F1D Waterfall.png
Nexedge NXDN Trunking Radio trunking control channel. 171.3 MHz171,300,000 Hz
171,300 kHz
NFM 8,000 Hz8 kHz
0.008 MHz
Worldwide NXDNTrunking Waterfall.png
Nissan Car Key Wireless entry rolling code car key. 315 MHz315,000,000 Hz
315,000 kHz
, 433 MHz433,000,000 Hz
433,000 kHz
AM/FM 40,000 Hz40 kHz
0.04 MHz
Worldwide NissanCarFob Waterfall.png
Orbcomm Orbcomm satellites are used for monitoring and sending short text messages. 137 MHz137,000,000 Hz
137,000 kHz
, 150 MHz150,000,000 Hz
150,000 kHz
NFM 15,000 Hz15 kHz
0.015 MHz
Worldwide Orbcomm Waterfall.jpg
Over the Horizon Radar (OTH) Used by militaries for very long range radar systems. 6 MHz6,000,000 Hz
6,000 kHz
None 0 Hz0 kHz
0 MHz
Worldwide OTHRadar Waterfall.png
Overlapping RTTY Multiple overlapping RTTY signals sent by hams. 5,346 MHz5,346,000,000 Hz
5,346,000 kHz
USB 8,000 Hz8 kHz
0.008 MHz
Worldwide OverlappingRTTY Waterfall.png
PAL TV Analogue TV Signal. Now phased out in most of the world. 60 MHz60,000,000 Hz
60,000 kHz
None 5,000,000 Hz5,000 kHz
5 MHz
Worldwide No Audio File PALTV Waterfall.jpg
PLUTO II Radar Audio sample recorded in RAW mode. The signal is periodic. It can broadcast for several minutes, before going silent, and reappearing at another frequency. It has been seen in short bursts. 24.055 MHz24,055,000 Hz
24,055 kHz
, 25 MHz25,000,000 Hz
25,000 kHz
, 25.37 MHz25,370,000 Hz
25,370 kHz
, 26.37 MHz26,370,000 Hz
26,370 kHz
Unknown 20,000 Hz20 kHz
0.02 MHz
Norway Unknown 24 Waterfall.png
POCSAG Pager digital signal. 151 MHz151,000,000 Hz
151,000 kHz
, 960 MHz960,000,000 Hz
960,000 kHz
, 138 MHz138,000,000 Hz
138,000 kHz
, 153 MHz153,000,000 Hz
153,000 kHz
, 153.5 MHz153,500,000 Hz
153,500 kHz
, 454 MHz454,000,000 Hz
454,000 kHz
, 173 MHz173,000,000 Hz
173,000 kHz
, 466.075 MHz466,075,000 Hz
466,075 kHz
, 169.625 MHz169,625,000 Hz
169,625 kHz
, 35.22 MHz35,220,000 Hz
35,220 kHz
, 35.58 MHz35,580,000 Hz
35,580 kHz
, 43.22 MHz43,220,000 Hz
43,220 kHz
, 43.58 MHz43,580,000 Hz
43,580 kHz
, 152.008 MHz152,007,500 Hz
152,007.5 kHz
, 152.48 MHz152,480,000 Hz
152,480 kHz
, 157.45 MHz157,450,000 Hz
157,450 kHz
, 158.1 MHz158,100,000 Hz
158,100 kHz
, 158.7 MHz158,700,000 Hz
158,700 kHz
, 163.25 MHz163,250,000 Hz
163,250 kHz
, 454.013 MHz454,012,500 Hz
454,012.5 kHz
, 454.5 MHz454,500,000 Hz
454,500 kHz
, 462.75 MHz462,750,000 Hz
462,750 kHz
, 465 MHz465,000,000 Hz
465,000 kHz
, 929.988 MHz929,987,500 Hz
929,987.5 kHz
, 931.988 MHz931,987,500 Hz
931,987.5 kHz
, 931.438 MHz931,437,500 Hz
931,437.5 kHz
, 931.938 MHz931,937,500 Hz
931,937.5 kHz
, 148.338 MHz148,337,500 Hz
148,337.5 kHz
, 450.375 MHz450,375,000 Hz
450,375 kHz
, 450.325 MHz450,325,000 Hz
450,325 kHz
, 465.97 MHz465,970,000 Hz
465,970 kHz
, 152.27 MHz152,270,000 Hz
152,270 kHz
, 462.925 MHz462,925,000 Hz
462,925 kHz
, 929.013 MHz929,012,500 Hz
929,012.5 kHz
, 931.013 MHz931,012,500 Hz
931,012.5 kHz
NFM 9,000 Hz9 kHz
0.009 MHz
Worldwide POCSAG Waterfall.png
Police Idling Walkie Talkie Radio Signal I found out what Unknown 453 was, the one that I posted a few weeks ago, it is a police idling signal, apparently the police signal belongs to the remote SDR I was listening to, but I got my own SDR now. So yeah, it is an idling signal for a police walkie-talkie 453.6 MHz453,600,000 Hz
453,600 kHz
 ? 0 Hz0 kHz
0 MHz
Unknown Police idling.png
Portable Traffic Lights Signals sent from portable traffic lights that are often used at roadworks. 154.463 MHz154,463,000 Hz
154,463 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide PortTrafLight Waterfall.png
Project 25 (P25) Digital voice signal. 860 MHz860,000,000 Hz
860,000 kHz
, 500 MHz500,000,000 Hz
500,000 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
Worldwide P25 Waterfall.png
Project 25 Trunking (P25) Radio trunking control channel. 860 MHz860,000,000 Hz
860,000 kHz
NFM 12,500 Hz12.5 kHz
0.0125 MHz
Worldwide P25Trunk Waterfall.png
Pulse Coded Modulated (PCM) RC Toy Signal used for remote control (RC) Toys. 27.145 MHz27,145,000 Hz
27,145 kHz
, 49 MHz49,000,000 Hz
49,000 kHz
None 0 Hz0 kHz
0 MHz
Worldwide PCMRCToy Waterfall.png
Radio Teletype (RTTY) Radio Teletype, also known as RTTY. 24.9 MHz24,900,000 Hz
24,900 kHz
, 4.583 MHz4,583,000 Hz
4,583 kHz
, 7.646 MHz7,646,000 Hz
7,646 kHz
, 10.101 MHz10,100,800 Hz
10,100.8 kHz
, 11.039 MHz11,039,000 Hz
11,039 kHz
, 14.467 MHz14,467,300 Hz
14,467.3 kHz
USB, LSB 200 Hz0.2 kHz
2.0e-4 MHz
, 450 Hz0.45 kHz
4.5e-4 MHz
Worldwide RTTY Waterfall.png
ReFLEX Two-way paging variant of FLEX. 896 MHz896,000,000 Hz
896,000 kHz
, 902 MHz902,000,000 Hz
902,000 kHz
, 929 MHz929,000,000 Hz
929,000 kHz
, 932 MHz932,000,000 Hz
932,000 kHz
, 940 MHz940,000,000 Hz
940,000 kHz
, 941 MHz941,000,000 Hz
941,000 kHz
, 940.21 MHz940,210,000 Hz
940,210 kHz
NFM 40,000 Hz40 kHz
0.04 MHz
, 10,000 Hz10 kHz
0.01 MHz
USA ReFLEXthumb.jpg
Robot 72 SSTV SSTV is short for slow scan television. A method that hams and radio pirates use to transmit low resolution images. This particular image is from a fleetsatcom pirate. 252.15 MHz252,150,000 Hz
252,150 kHz
NFM 12,000 Hz12 kHz
0.012 MHz
Worldwide Robot72SSTV Waterfall.jpg
SITOR-B SITOR-B used for broadcasting messages out at sea. 0.002 MHz2,000 Hz
2 kHz
USB Worldwide NO Waterfall.jpg
STANAG 4285 Standardization Agreement (STANAG) 4285. NATO standard for HF communication. 1.89 MHz1,890,000 Hz
1,890 kHz
, 22.7 MHz22,700,000 Hz
22,700 kHz
USB 2,500 Hz2.5 kHz
0.0025 MHz
Worldwide Stanag4285 Waterfall.png
Serdolink Serdolink (aka Crowd-36) is a MFSK signal mainly used by the Russian diplomatic service and military. 0.0157 MHz15,650 Hz
15.65 kHz
USB 300,000 Hz300 kHz
0.3 MHz
Russia Unknown1.png
Slow Scan Television (SSTV) Slow-scan television (SSTV) is a method for picture transmission used by amateur radio operators to transmit and receive images. 0.0142 MHz14,230 Hz
14.23 kHz
USB 0 Hz0 kHz
0 MHz
Seattle SSTV Example.png
Swedish POCSAG Minicall A short POCSAG 1200 signal used in electric plants and remote transformer and insulation stations. 161 MHz161,000,000 Hz
161,000 kHz
NFM 20,000 Hz20 kHz
0.02 MHz
Sweden SwedishMinicallPocsag Waterfall.png
Tactical Data Link (TDL) Tactical Data Link (Also known as Tactical Digital Information Link (TADIL) 9.202 MHz9,202,000 Hz
9,202 kHz
, 3.532 MHz3,532,000 Hz
3,532 kHz
DSB 6,200 Hz6.2 kHz
0.0062 MHz
Europe TDLthumb.png
Terrestrial Trunked Radio (TETRA) A professional mobile radio and two-way transceiver (walkie-talkie) specification 380 MHz380,000,000 Hz
380,000 kHz
, 430 MHz430,000,000 Hz
430,000 kHz
NFM 25,000 Hz25 kHz
0.025 MHz
Europe TETRA Waterfall.png
Toyota Car Key Wireless entry rolling code car key. 315 MHz315,000,000 Hz
315,000 kHz
, 433 MHz433,000,000 Hz
433,000 kHz
AM/FM 40,000 Hz40 kHz
0.04 MHz
Worldwide ToyotaCarFob Waterfall.png
Upper Sideband Voice Single side band, specifically upper side band. Used in the HF band by amateur radio hams and aircraft weather reports. 6 MHz6,000,000 Hz
6,000 kHz
USB 1,900 Hz1.9 kHz
0.0019 MHz
Worldwide USB Waterfall.png
VHF Data Link (VDL2) A modern version of ACARS. 136.975 MHz136,975,000 Hz
136,975 kHz
USB 25,000 Hz25 kHz
0.025 MHz
Worldwide VDL2 Waterfall.jpg
Vaisala RS92SGP Weather Balloon (Radiosonde) Weather balloon (radiosonde) telemetry data. 400 MHz400,000,000 Hz
400,000 kHz
NFM 5,500 Hz5.5 kHz
0.0055 MHz
Worldwide RS92SGP Waterfall.png
Voice Frequency Telegraph (VFT) Consists of multiple RTTY channels over one audio bandwdith. 7.454 MHz7,453,500 Hz
7,453.5 kHz
USB 8,000 Hz8 kHz
0.008 MHz
Worldwide VFT Waterfall.jpg
Weatherfax Used by mariners for receiving fax weather reports. Also Kyodo News, a Japanese newspaper transmits entire pages via Weatherfax. 3 MHz3,000,000 Hz
3,000 kHz
, 16 MHz16,000,000 Hz
16,000 kHz
NFM 5,500 Hz5.5 kHz
0.0055 MHz
Worldwide Weatherfax Waterfall.png
Wideband FM (WFM) Used for typical broadcast radio, and in some wireless headsets and speakers. 87.5 MHz87,500,000 Hz
87,500 kHz
, 108 MHz108,000,000 Hz
108,000 kHz
, 65 MHz65,000,000 Hz
65,000 kHz
, 74 MHz74,000,000 Hz
74,000 kHz
, 76 MHz76,000,000 Hz
76,000 kHz
, 90 MHz90,000,000 Hz
90,000 kHz
, 860 MHz860,000,000 Hz
860,000 kHz
WFM 54,000 Hz54 kHz
0.054 MHz
Worldwide WFM Waterfall.jpg

Requested Signals

If you have these signals (or any other not on the list) please either add the waterfall image and sample sound as an MP3 to the wiki and edit the page, or email me at rtlsdrblog__AT__gmail__DOT__com for addition. Please consult the instructions here - Adding An Example Signal.

Automatic Link Establishment (ALE)
Continuous Wave (CW)
Emergency Managers Weather Information Network (EMWIN)
Multi Frequency Shift Keying (MFSK)
NFM Voice
Tire Pressure Monitoring System (TPMS)
Voice Inversion Scrambling

Unidentified Signals

If you have an unidentified signal that you would like the wiki readers to take a look at please either email me at rtlsdrblog__at__gmail__dot__com or add it as a page yourself with the Category:UNID. Include as much information about the signal as you can including frequency, waterfall images, MP3 sound samples, location, bandwidth and anything else you can think of. Please add the signal using the correct template so that it will show up properly on the main page. Please consult the instructions here - Adding An Example Signal.

If you happen to be able to identify a signal, please either edit the wiki, make a note in the wiki discussion page (in the signal page click the discussion tab at the top), or email me at rtlsdrblog__at__gmail__dot__com.

Signal Type Description Frequency Mode Bandwidth Location Sample Audio Waterfall Image
ADN-like shifting frequencies signal It shows up as several mirror-images throughout the spectrum, some very close to each other, all of them exact copies of the original signal 800 MHz800,000,000 Hz
800,000 kHz
, 900 MHz900,000,000 Hz
900,000 kHz
, 856 MHz856,000,000 Hz
856,000 kHz
NFM Portugal No Audio File Waterfall.png
Beeper 403.959 MHz403,959,000 Hz
403,959 kHz
FM 1,000 Hz1 kHz
1.0e-3 MHz
Australia Beeper.png
Unknown 142p398 Posting a unidendified sound. Sound like a MotoTrbo but chopped. Frequency hopping? 142.399 MHz142,398,825 Hz
142,398.825 kHz
NFM 8,000 Hz8 kHz
0.008 MHz
Drammen, Norway Unknown 142p398.jpg
Unknown 148 Identified - POCSAG 148.641 MHz148,641,000 Hz
148,641 kHz
NFM 25,000 Hz25 kHz
0.025 MHz
Brisbane, Queensland 148.641.png
Unknown 151 Carrier repeats every 4 seconds, signal every 5 seconds. Received in New London County. 151.195 MHz151,195,000 Hz
151,195 kHz
NFM 6,000 Hz6 kHz
0.006 MHz
Connecticut, USA Unknownsignal1.png
Unknown 155p5 I have found an unknown signal at 155.500 Mhz in germany, Hameln near Hannover. This continuously signal has a bandwidth of 15 kHz. 155.5 MHz155,500,000 Hz
155,500 kHz
 ??? 15,000 Hz15 kHz
0.015 MHz
Germany, Hameln near Hannover Unknown 155p5.jpg
Unknown 155p6 I added the interesting signal's waterfall image and sound and I record it in Turkey, Central Anatolia. I hope it can be solved 155.6 MHz155,600,000 Hz
155,600 kHz
 ??? Turkey, Central Anatolia Unknown 155p6.jpg
Unknown 158 I found this signal on 158.665 MHz, which according to Industry Canada belongs to our local public works department. 158.665 MHz158,665,000 Hz
158,665 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide Unknown158 Waterfall.jpg
Unknown 161p995 Noisy signal from Italy. 161.995 MHz161,995,000 Hz
161,995 kHz
NFM Italy Unknown 161p995.jpg
Unknown 167 I've recieved this signal at 167,400MHz and recorded it as NFM (Bandwidth 8000). Location: Madrid, Spain. 167.4 MHz167,400,000 Hz
167,400 kHz
NFM 8,000 Hz8 kHz
0.008 MHz
Madrid, Spain Unknown 167.png
Unknown 173 None. 173.262 MHz173,262,000 Hz
173,262 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide Unknown173 Waterfall.png
Unknown 175p4968 I found this very slow frequency-modulated signal on 175.4968 MHz. In Belgium, this part of the spectrum is allocated for wireless microphones and audio connections for broadcast services. It might also originate from the Netherlands, as I'm not living far from the border. Every few minutes, the signal shifts up about 500 Hz for a while, before shifting back down. 175.497 MHz175,496,800 Hz
175,496.8 kHz
USB Belgium Unknown 175p4968.jpg
Unknown 20 IDENTIFIED - This is very likely to be Over the Horizon RADAR. 20 MHz20,000,000 Hz
20,000 kHz
 ? 0 Hz0 kHz
0 MHz
Worldwide OTH Ex2 Waterfall.jpg
Unknown 21p075 I have seen this signal several places in the amateur bands on HF. 21.075 MHz21,075,000 Hz
21,075 kHz
, 28.121 MHz28,121,000 Hz
28,121 kHz
USB 500 Hz0.5 kHz
5.0e-4 MHz
Norway Unknown 21p075 Waterfall.png
Unknown 220 Received in New London County. 220.914 MHz220,914,000 Hz
220,914 kHz
NFM, RAW 3,000 Hz3 kHz
0.003 MHz
Connecticut, USA Unknown 220waterfall.png
Unknown 28p597 28.597 MHz28,597,000 Hz
28,597 kHz
AM Croatia Unknown28597.png
Unknown 40 Hi,I found a strange signal on 40.693mhz, maybe you know what this is and/or could add this to your sample list. It has a bandwidth of about 4000-5000 hz and the low part repeats about every 2,5 seconds, the high part every 5 seconds (as shown in picture 1 rec1.png). Sometimes (2-3 times an hour) this signal has some variations - show in picture 2 rec2.png. I also provided you an audio sample of about 20 seconds, recorded in RAW. Do you know what this signal could be? Its online 24/7 since a month now. regards, Auge 409.6 MHz409,600,000 Hz
409,600 kHz
NFM 5,000 Hz5 kHz
0.005 MHz
Worldwide Unknown40 Waterfall.jpg
Unknown 40 2 Last Thursday I received some digital signals very close to each other that I have never heard before, it looked like this: and on NFM it sounded like this: appeared during sporadic E conditions and I heard a lot of people from the UK on the 50MHz band. It could very well be a signal originating from the UK, I received the signal in the south of The Netherlands. 40 MHz40,000,000 Hz
40,000 kHz
NFM 0 Hz0 kHz
0 MHz
South of The Netherlands Unknown40 2 Waterfall.jpg
Unknown 40 3 Sounds like a ringing phone. 40.672 MHz40,672,000 Hz
40,672 kHz
NFM 0 Hz0 kHz
0 MHz
Unknown40 3 Waterfall.jpg
Unknown 409 Unknown chirping like sound. 409.6 MHz409,600,000 Hz
409,600 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide Unknown409 Waterfall.jpg
Unknown 423p15 Unknown at 423.15 MHz. 423.15 MHz423,150,000 Hz
423,150 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
 ??? Unknown 423p15.png
Unknown 441p660 441.66 MHz441,660,000 Hz
441,660 kHz
FM Croatia Unknown 441p660.png
Unknown 443p685 Possibly "Autocab" signal. 443.685 MHz443,685,000 Hz
443,685 kHz
FM Croatia Unknown 443p685.png
Unknown 443p886 443.886 MHz443,886,000 Hz
443,886 kHz
FM Croatia Unknown 443p886.png
Unknown 443p936 443.936 MHz443,936,000 Hz
443,936 kHz
FM Croatia Unknown 443p936.png
Unknown 445 Unknown. Sent from video clip.  ? 0 Hz0 kHz
0 MHz
UK Unknown445 Waterfall.png
Unknown 446 I've found a strange signal on 446 MHZ Band in Italy, it seems like a multi channel signal (maybe RTTY?). I'm attaching an image and a 2 seconds IQ sample. 446 MHz446,000,000 Hz
446,000 kHz
USB 0 Hz0 kHz
0 MHz
Worldwide Unknown446 Waterfall.jpg
Unknown 452p862 452.863 MHz452,862,550 Hz
452,862.55 kHz
CW 1,990 Hz1.99 kHz
0.00199 MHz
Unknown Unknown 452p862.png
Unknown 455 None. 455 MHz455,000,000 Hz
455,000 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide Unknown455 Waterfall.png
Unknown 458p208 I have the following signal in attachment, which is transmitted all the time at roughly 458.208 MHz (center frequency), in four distinct frequencies separated by about 12.5 KHz. Each of the signals is roughly 5 KHz in bandwidth. The signals are received in Portugal near Lisbon. 458.208 MHz458,208,000 Hz
458,208 kHz
 ??? 5,000 Hz5 kHz
0.005 MHz
Portugal near Lisbon Unknown 458p208.jpg
Unknown 467p260 A few months ago I was scanning the UHF band inside my apartment with a Baofeng UV-5R when suddenly I've heard what in a first moment I believed that was packet radio. I have done a lot of packet radio, APRS, APT, AMTOR, PSK and other digital communications around the last 10 years but this.. I didn't know what the hell is. I heard it at 467.260 MHz, it is powerful as hell, since I can hear it using the stock antenna on my handy, and also I can hear it around 2km of my apartment. 467.26 MHz467,260,000 Hz
467,260 kHz
XXX 0 Hz0 kHz
0 MHz
 ??? 150x250px
Unknown 469 Found on 469.975 FM on my ICOM HT can't get waterfall cause I don't have my RTL-SDR here. When I'll have a better recording I'll send it. It sounds like the portable traffic lights but it not the same... 469.975 MHz469,975,000 Hz
469,975 kHz
FM 0 Hz0 kHz
0 MHz
Israel [[Image:|150x250px]]
Unknown 550 Unknown FSK? 550.06 MHz550,060,000 Hz
550,060 kHz
USB 5,000 Hz5 kHz
0.005 MHz
Worldwide Unknown550 Waterfall.jpg
Unknown 648 Frequency shifting. Received in New London County. 648.01 MHz648,010,000 Hz
648,010 kHz
CW 300 Hz0.3 kHz
3.0e-4 MHz
Connecticut, USA Unknown 648waterfall.png
Unknown 75p219 75.219 MHz75,219,000 Hz
75,219 kHz
FM Croatia Unknown 75p219.png
Unknown 83 Unknown 83.7 MHz83,700,000 Hz
83,700 kHz
 ? 0 Hz0 kHz
0 MHz
Unknown Unknown83 Waterfall.jpg
Unknown 856 The antenna has a Yagi pointed to West from 23.5° South latitude, 47.46° West longitude. The signal can be local or from the sky. The signal is horizontal polarized. 856 MHz856,000,000 Hz
856,000 kHz
Unknown 0 Hz0 kHz
0 MHz
Worldwide No Audio File Unknown856 Waterfall.jpg
Unknown ALE Can someone verify this signal? Someone suggested it's a "Japanese MAFF 8FSK", but not sure. 6 MHz6,000,000 Hz
6,000 kHz
USB 0 Hz0 kHz
0 MHz
Worldwide UnknownALE Waterfall.png
Unknown Chirping 2 Continuous bursts. Audio sample recorded in NFM. Comment: Transmitted by a company that has water purifiers near my city. I know because i’ve done 2 stages in this company and i’ve seen the radio. It should recive the water level from the tanks and other things. 162.863 MHz162,863,000 Hz
162,863 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide UnknownChirp2 Waterfall.png
Unknown Data Chirping Continuous signal. Audio sample recorded in NFM. 152.652 MHz152,652,000 Hz
152,652 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide UnknownDataChirp Waterfall.png
Unknown Helix Helix shape possibly due to under sampling in the waterfall display? 456.368 MHz456,368,000 Hz
456,368 kHz
NFM Unknown Unknown Helix.JPG
Unknown Lines Unknown bunch of lines. 0 MHz0 Hz
0 kHz
NFM 8,000 Hz8 kHz
0.008 MHz
Unknown LTR Waterfall.png
Unknown MPT1327-Like Sounds like MPT1327 but unable to decode with Unitrunker or Trunkview. 468.488 MHz468,487,500 Hz
468,487.5 kHz
NFM 8,000 Hz8 kHz
0.008 MHz
France Fouine91 MPT1327-Like.jpg
Unknown Pager-Like Unknown signal that sounds similar to a POCSAG pager, but seems not to be. 26.65 MHz26,650,000 Hz
26,650 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
Worldwide UnknownPagerLike Waterfall.jpg
Unknown Pear Here was a pear shape happened 3 times tonight.Sorry to say I didn`t get the audio. I was lucky to get 2 images.  ???  ??? No Audio File Unknown pear 1.png
Unknown Pulsing Periodic pulses. Sound sample recorded in USB mode. Possibly a GlobeWireless signal. 6 MHz6,000,000 Hz
6,000 kHz
USB 0 Hz0 kHz
0 MHz
Worldwide UnknownPulsing Waterfall.png
Unknown Ringing Repeats every minute. 154.646 MHz154,646,000 Hz
154,646 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide UnknownRinging Waterfall.jpg
Unknown Thin Pulsing Unknown thin pulses. 0 MHz0 Hz
0 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
Unknown UnknownThinPulses Waterfall.png
Unknown Trunking Sounds like Motorola Type II smartnet, but Unitrunker does not recognize. 452.325 MHz452,325,000 Hz
452,325 kHz
NFM 0 Hz0 kHz
0 MHz
Worldwide UnknownTrunking Waterfall.png
Unknown trunking or data Unidentified data signal, possibly trunking 131.188 MHz131,187,500 Hz
131,187.5 kHz
FM Narrow 12,500 Hz12.5 kHz
0.0125 MHz
UK 133187500 strangetrunking.png
Unknown-1536125 This signal continuously broadcasts in short blips. 151.782 MHz151,781,500 Hz
151,781.5 kHz
, 469.761 MHz469,760,500 Hz
469,760.5 kHz
, 153.613 MHz153,612,500 Hz
153,612.5 kHz
NFM 10,000 Hz10 kHz
0.01 MHz
USA 153 612 500-WF.png
Unknown-162 Signal was captured in Belarus(near Russia border). It is emitting everytime. Maybe this is airport signals... 162.3 MHz162,300,000 Hz
162,300 kHz
AM 12,500 Hz12.5 kHz
0.0125 MHz
Belarus 162-343.jpg
Weird moving signal Found this signal while just scanning around. Original thought it could be something to do with the local airport, such as radar or something. But this signal has only appeared in the last couple of days. 117 MHz117,000,000 Hz
117,000 kHz
USB 3,000 Hz3 kHz
0.003 MHz
United Kingdom No Audio File Weird signal.png


Feel free to make comments about unidentified signals that you might know or anything else here.

Anonymous user #1

201 days ago
Score 0+-
unknown 469 is a signal from wireless alarm monitoring services. Homes and businesses with alarm systems can have a wireless transmitter for backup or for locations without a phone line.

Anonymous user #2

201 days ago
Score 0+-
unknown 550 is most likely noise from the USB interface of a PC or noise from a monitor. I have seen a very similar signal and found it to be noise from the PC.

Anonymous user #3

192 days ago
Score 0+-

I'd like to put in a request for info and signal sample on RD-LAP and also on the Motorola MDT signals that preceded the 19.2 kbps rdlap, such as MDC4800.

This is sold by Motorola as part of their DataTAC network package. It used to be active as part of the ARDIS network nationwide, but I believe that has all been retired (maybe still used somewhere? Not 100% sure)

Also, it is still used by some police departments and others with private datatac networks.


189 days ago
Score 0+-

'Unknown Lines' must be LTR Standard/LTR PassPort/LTR Net

I've submitted some samples to the admin, I think, he will put them here soon

Anonymous user #4

183 days ago
Score 0+-
Unknown chirping 2 I've been seeing something very similar on 936.924MHz USA Virginia.

Anonymous user #5

183 days ago
Score 0 You
Unknown Pager-Like is a variant of a FLEX pager.

Anonymous user #6

157 days ago
Score 0+-
Unknown Musical is JT65

Anonymous user #5

156 days ago
Score 0 You
Unknown Musical is JT65a.

Anonymous user #5

143 days ago
Score 0 You
How about a tutorial on how to "Tune In" to certain signals, when do you use LSD/USB what is "Shift" for CW ect.. I can't seem to find a good reference, but here it is very clear on how to process and recognise signals

Anonymous user #7

142 days ago
Score 0+-
Unknown 72 is a signal "BIIS1200" protocol.

Anonymous user #7

136 days ago
Score 0+-

Can someone confirm from this screenshot that it is encrypted voice I'm using DSD and i can partaily hear voices it sounds weird its hard to explain it i can definitely hear a voice but i'm unable to make out if it is male or female because the voice will go deep then soft very quickly so i'm unable to make out what is being said.

<a href="http://www.d...mqvtzh4j.png" target="_blank"><img src="http://www.d...4j_thumb.png" border="0" alt="Unknown155"/></a>

Anonymous user #7

132 days ago
Score 0+-
Unknown 409 is probably APRS / AFSK decodeable with http://sourc...ojects/qtmm/ at FM mode

Anonymous user #8

131 days ago
Score 0+-
Unknown ALE is an Over The Horizon Radar which emanates from Asia and can be heard on various HF bands and frequencies. It is quite common on the 40M amateur radio band in New Zealand amongst others.

Anonymous user #9

81 days ago
Score 0+-
That wasn't a radar!

Anonymous user #10

127 days ago
Score 0+-

Unknown 433

Could be a cheap home weather station. But 433 MHz is full of mystery signals for consumer electronics like alarm remotes and other sensors.


121 days ago
Score 1+-
I have added a page in the infamous Californian electricity "Smart Meter"

Anonymous user #7

121 days ago
Score 0+-
Unknown Trunking is probably TETRA

Anonymous user #11

113 days ago
Score 0+-
I am listening to an unknown signal on 13505 khz AM mode on 10-5-14 at 11:45 am EST which sounds something like a remote control when aimed at a radio(MW or LW). Pulses are short and seem to be "communicating" with each other(close and distant).

Anonymous user #5

106 days ago
Score 0 You
Unknown 15650 is Crowd-36 and Unknown 28p957 is a short-distance radar.

Anonymous user #12

94 days ago
Score 0+-

I found this web page full of digital signals:

Listening to theese signals I think that Unknown Chirping 2 could be mmp-4800 but there are also other similar modes like SEAR, SCADA.

Anonymous user #9

92 days ago
Score 0+-

I've found a russian program to analyze signals its name is: Signals Analyzer.

I don't know how to use it but i think that is an interesting program.

Anonymous user #9

81 days ago
Score 0+-
Where is the 8 FSK system?

Anonymous user #5

74 days ago
Score 0 You
Unknown 24 is an OTHR, specifically the PLUTO II radar.

Anonymous user #5

57 days ago
Score 0 You
The one by IN87RG might not be from his location, it is from the UOT WebSDR possibly.

Anonymous user #13

46 days ago
Score 0+-
FSK441 is missing, so is Olivia, Domino, etc..

Anonymous user #14

41 days ago
Score 0+-
Unknown 40!! I've heard it too.. there is usually something idling.. sometimes the transmission is longer.. one day there was two stations of it. here https://www....=GTIQnC3f5U0

Anonymous user #9

40 days ago
Score 0+-
My pc not detect sounds on this site, may help me please?

Anonymous user #9

38 days ago
Score 0+-
Unknown 155p6, signal from Turkey, Central Anatolia is APCO25 (P25) Signal.


32 days ago
Score 0+-
Unknown 72 can be decoded with MultiPSK: BIIS protocol (Binary Interchange of Information and Signaling)

Anonymous user #12

30 days ago
Score 0+-
I found Unknown chirping 2 at cca 447.7MHZ, multiple signals, Slovakia.

Anonymous user #5

24 days ago
Score 0 You
Can confirm "Unknown-1536125", hear it all the time on 462.407 MHz and 173.226 MHz.

Anonymous user #5

23 days ago
Score 0 You anywhere in the Massachusetts, USA area by chance?


23 days ago
Score 0+-
Original poster here, no, but I do live in Connecticut. New London County. The 173.226 MHz sounds like a time signal with an incomprehensible identification every 10 seconds, and the 462.407 MHz one sounds like a beacon.


22 days ago
Score 0+-
OP here. I don't know why I hadn't thought of this before, but I did a little Googling and found that the two VHF freq's are registered to an address of a town water supply. Street view shows two water tanks/towers at that address, so I'm guessing this is some sort of monitoring system. Saw your video- the waterfall looks similar, at least, to the one I posted, but it didn't sound to me like the same signal.


16 days ago
Score 0+-
They all seem very different, yes. But I think they're all the same signal.

Anonymous user #5

24 days ago
Score 0 You
Unknown ionosonde-like is not an ionosonde, but it is a sounder. Specifically, the 29B6 Over The Horizon Radar sounder is pictured on the University of Twente WebSDR, it makes a paddling noise to check if a frequency is not in use. It isn't very effective since it commonly overlaps HAM bands and SW broadcast bands.

Anonymous user #5

15 days ago
Score 0 You
Thanks, i'll update it!

Anonymous user #15

24 days ago
Score 0+-

А это уважаемые товарищи идет канал видео ТВ. Где то рядом на 2 кгц ниже или выше идет звук.



5 days ago
Score 0+-
Unknown 148 is POCSAG. First is POCSAG 512, second is POCSAG 1200. Unknown 21p075 is OLIVIA, specifically, OLIVIA 8-250 in the audio file.

Anonymous user #16

4 days ago
Score 0+-
thanks friend

Anonymous user #12

3 days ago
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In response to the person who posted about the "Police Idling Walkie Talkie Radio Signal"

I have also found the same signal in the UK which is on the 70cm band it pulses every few seconds with 12MHz BW, I also noticed there is an other pulse signal 30 mhz apart which pulses at a slower pace once every 4 or 5 pulses.


2 days ago
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how u get 12 mhz bandwidth


4 hours 27 minutes ago
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Unknown Lines is logic trunked radio.
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