High Frequency Beacon

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A QSL card from a High Frequency beacon

High Frequency Beacon is a colloquial term for an unlicensed radio beacon that does not follow government regulations for operation (such as Part 15), and is technically illegal. Unlicensed HF beacons which operate legally, according to rules for low power transmissions are classified as HiFERs. See also: data link networks and RC systems in the 26-28 MHz or 11 meter band region that operate as de facto beacons. These systems may be found primarily on 26995, 27045, 27095, 27145, 27195 and 27255 kHz but numerous other frequencies are used worldwide.

There is a separate list of Part 15 Beacons



PRV (6852 kHz) under test

There are many of these beacons, quite a few are run as propagation experiments. Due to their nature, the exact location of these stations is generally not published, although many are believed to operate from remote locations in the deserts of the southwest USA. Likewise, these stations tend to suddenly appear and disappear from the air. Most run with very low power levels of just hundreds or even tens of milliwatts of power, and are often solar powered, so they can be hidden in open areas. Some are switched via a photocell, so they only operate at night, running off of a battery that is charged during the daytime by a solar panel.

There is a message board where listeners can report reception of beacons, it is also useful to see what other folks are presently hearing:

North American High Frequency Beacons

4096.85 "Marin Dit", 24/7 5-10 mW, harmonic of 8193.77 radiates better
Freq (kHz) Station ID Location Operation Notes Last reported
2008.4 Dits Nevada USA (CW ditter 130 mW) N/S dipole, battery power, night only. Approximate CW timing: 191 millisecond dit duration, 1.55 second repetition, 1.5 minute ON cycle, 3 minute OFF cycle [1] December 27, 2018
2097 A Arizona - 15 watts max., 10 second repetition, 24/7 [2] July 18, 2023
4094 UFO unknown id's UFO TMP three times, after TMP two numbers are sent then back to dashes. On the air around Nov 2020 2021
4095.650 DW SW Desert Desert Whooper - (1 Watt) 30 Whoops & ID - After 6 cycles sends Bat-Outside Temp -Inside Temp - Solar Panel current 24/7/365 https://www.hfunderground.com/board/index.php?topic=85047.0 July 23, 2023
4096.1 Dasher Joshua Tree N.P. 4.5 sec long dashes (about 13 dashes per min.) - big signal - north-facing dipole ('Coxie') 24/7 2021
4096.2 Buddha -Calif Desert Slow dasher called Buddha, was "Phallaxy" was "Viking". About 30 mW, daytime only. On for 3 seconds, off for 3 seconds 2021
4096.85 "Marin Ditter" Marin County 24/7 5-10 mW, 2nd harmonic of 8193.77 radiates better 2021
4097.08 Dasher unknown Slow Dasher, 2secs on and 2 secs off. Discovered Nov. 2020, it does appear to be related to 7997.2 kHz. The two dashers appear to be in sync. 2021
4097.1 Dasher unknown Fast Ditter. New in 2021 2021
4098.2 ~ 4104+ ZN Western USA Drifts up to 4104+ kHz during daylight hours, drifts down to 4098 kHz just after sunset, ZN sometimes heard run together like a prosign with an extra dash between the Z and N: "dah-dah-di-di-dah-dah-dit" or --..--. September 08, 2018
4100.1 H Unknown "H" repeated ID only, Source: HF Underground, 4 MHz Western USA Beacons September 10, 2018
4102.8 W... southeast California desert Windy beacon - see section on this page about the telemetry. Sends Morse code 'W' and series of dits - each dit correlating to a turn of its anemometer wind sensor, so if it is windy in the vicinity, it sends lots of dits; and no wind, no dits. TMP temperature (Fahrenheit), B battery voltage (decivolts). 24/7/365 2021
6700.4 Dasher Joshua N.P. About 62 dashes per min., 24/7 (Hexy2k) 2021
7998.1 HI Western USA Morse CW beacon. Approximate timing: 9.64 seconds repetition, dit duration 128 milliseconds 27 December, 2018
8191.7 Dasher Southwestern USA 4 second dash (somewhat variable), likely 2nd harmonic of Viking on 4095.86 kHz (Source: HF Underground Forum, 8 MHz Western USA Beacons) August 26, 2018
8192.7 Dasher Southwestern USA 2.3 second dash, likely 2nd harmonic of Haystack on 4096.38 kHz (Source: HF Underground Forum, 8 MHz Western USA Beacons) August 26, 2018
8193.7 Ditter Western USA 1.1 dits per second, MarinDit, also may be heard on 4096.86 kHz (Source: HF Underground Forum, 8 MHz Western USA Beacons) July 23, 2023
8200.1 D Unknown (Source: HF Underground Forum) September 08, 2018

European High Frequency Beacons

Freq (kHz) Station ID Location Operation Notes Last reported
1654.95 PRV Preveza, Greece Op: SW6HMU, QSL via sw6hmu@yahoo.gr (Source: ndblist). April 15, 2012
3810 SV1TEST Athens, Greece
no further info. (Source: UDXF)
4095.4 Common and Precious 5 JO62, Germany CW + RTTY. Telemetry Data. Active
4194 MX Europe Xtal controlled milliwatt beacon operated occasionally in europe. Sometimes sends straight carrier instead of ID.
4608 MXC Europe Xtal controlled milliwatt beacon operated occasionally in europe. Sometimes sends straight carrier instead of ID. Sister beacon to MX.
6375 Common and Precious 4 Berlin, Germany CW only. Solar powered with Battery backup. 1,5W into a short vertical. Operates 24/7. Sends SQL Cards on request. (Project Thread on HFU Board) Jule 17, 2018
6398.5 Common and Precious 2 Berlin, Germany CW only. Grid powered. 25W into a 1/2λ Dipole. Operates 24/7. Sends SQL Cards on request. (Project Thread on HFU Board) Jule 19, 2017
6547 PRV Preveza, Greece Op: SW6HMU, QSL via sw6hmu@yahoo.gr (Source: UDXF). Also reported on 6852.1 January 22, 2012
6815 SV1TEST Athens, Greece
Active 2010-2011, no further info. (Source: UDXF) (Youtube video)
X9Q S.E. Europe or
Middle East
Sporadic operation, no further info. (Source: UDXF) April 2012
6852.1 PRV Preveza, Greece 15 W Op: SW6HMU (Source: UDXF). (2) (3) Occasionally active with irregular schedule. QSLs via sw6hmu@yahoo.gr Former website [3] closed. Reported also on 6547.0 and 1654.95 kHz April 24, 2012
6994.8 - Norfolk, UK
7542 55555 W Europe or NE USA (Source: [4], N&O-173(5), UDXF) March 1, 2012
8000.0 QRP W. Europe reported on UDXF by european monitors February 9, 2014
10237.74 Common and Precious Berlin, Germany Grid powered. 5W into a 1/2λ Dipole. Operates 24/7. Sends SQL Cards on request. (Project Thread on HFU Board) Jule 19, 2017
26510 Common and Precious 3 Berlin, Germany 26.510 MHz Grid powered. 7W into a 5/8λ Vertical. Operates 24/7. Sends SQL Cards on request. (Project Thread on HFU Board) Jule 19, 2017
27140.8 50RS497 Russia 27.141 MHz 27.140 MHz USB 27.142 MHz LSB CW ID 50RS497
27141.6 14RS000 France JN38 200 mW power 27.1416 MHz 27.142 MHz beacon CW ID 14RS000 + long tone burst 27.140 MHz USB 27.143 MHz LSB
27175 153SD101 Thailand CB Channel 18 27.175 MHz CW ID 153SD101
27185 CW ID in FM mode Poland Morse code modulated FM CB Channel 19
27205 FM voice 11m CB repeater beacon Sweden simplex repeater - DTMF mid band CB channel 20 27.205 MHz
27245 siren-like "whoop" UK 1 watt power 1 pip per minute CB Channel 25 Solar Powered Beacon 27.245MHz 27MHz UK CB beacon
27255 CW Switzerland CB Channel 23 27.255 MHz - 10w power CW ID  : VVV VVV DE 15BS061 15BS061 10 WATT 11M BEACON LOC. JN37TN JN37TN
27405 1 dot/minute Germany 1 watt power 1 pip per minute CB Channel 40- 27.405 MHz
27499.6 50KS00 Moscow, Russia 2 watt power beacon 27.500 MHz LSB 27.4996 MHz CW ID 50KS00
27500 69BY Costa Rica CW ID 69BY [also on 27550 and 27610]
27500 Pips Mexico City CW pips (unknown TX power)
27500 38 Voice Greenland USB voice ID "38 voice beacon"
27500 153RT007 Thailand CW QRP Beacon 27.5 MHz 27.500 MHz 11m beacon frequency
27550 69BY Costa Rica CW ID 69BY alternate freq
27610 69BY Costa Rica CW ID 69BY primary 27.610 MHz 27609.9 27.609.9 MHz Sept 8, 2021

Telemetry Pirate Beacon

A telemetry pirate beacon may transmit some type of brief information about its surroundings, usually along with its identification symbol or some other identifying characteristic. Its transmission may have more content than the common dasher, ditter, or Morse code CW beacon, but the content can be mysterious or undocumented.

Windy Beacon

A good example of a telemetry pirate beacon is the Windy beacon which has been widely logged on approximately 4102.8 kHz CW. It is believed by some beacon listeners to be a solar powered pirate beacon, located somewhere in the rough back-country of southwestern USA.

Windy transmits Morse code telemetry of internal Temperature TMPfff (where fff is degrees Fahrenheit), Battery Voltage Bvvv (where vvv is decivolts), and 5 intervals of "W" followed by wind velocity dit pulses corresponding to revolutions of its ambient wind sensor. The typical timing of the Windy beacon telemetry is as follows: A 26 second temperature and battery interval; followed by 5 intervals of 13 seconds each for wind telemetry; with a total cycle time of approximately 135 seconds, repeating 24/7/365.

4102 kHz Windy pirate beacon telemetry diagram

Desert Whooper

This telemetry beacon broadcasts on 4095.70 and has been logged widely on the West Coast, up into Canada, as far west as Hawaii and as far east as Maryland. It sends a Morse Code ID of DW, then thirty upward 150 Hz sweeps (whoops), repeats 6 times then sends telemetry: BAT is in volts DC. oTMP is in degrees F with a calibrated outdoor thermistor, iTMP is in degrees F using a digital two wire sensor within the weathertight box and PV is in milliAmps to monitor solar panel performance.

The antenna is a 1/2 wave dipole oriented North/South and raised 0.15 wavelength above the desert soil to create a more vertical but omni-like pattern known as NVIS. The 1:1 balun is home made and measured VSWR is close to 1.1 to 1 for 1 Watt of transmit power.

QSL Card


See also

27 MHz beacon 69BY in Costa Rica on 27.610 MHz 27610 kHz


  1. Ary Boender: "Numbers and Oddities", issue 162, March 2011, pp. 17
  2. Ary Boender: "Numbers and Oddities", issue 156, September 2010, pp. 15-16
  3. "PRV" was often reported during the past few months and was unid until Linkz submitted a link to websites about this station. Linkz writes: I have no idea if this station is legit or a pirate. It's operator is Eystathios Karastathis (SW6HMU) from Preveza, Greece. He writes on his blog "PRV - 6852 kHz 15w cw BEACON with Dipole Ant on the air 17.30 pm- 8.00 am". According to his blog there is also a MF beacon "PRV beacon 500-531 khz am/cw 400 Watt" and a local AM broadcasting station "Studio 421" on 1655 kHz”. This beacon was last reported to UDXF on December 31, 2011.
  4. Ary Boender: "Numbers and Oddities", issue 159, December 2010, pp. 23.
  5. Ary Boender: "Numbers and Oddities", issue 173, February 2012, pp. 29.

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