Sounds from Space


Sounds from Amateur Radio Satellites 1986-1995


This section is dedicated to satellites built and operated by Radio Amateurs. Satellites built by AMSAT organizations around the world and were called AMSAT-OSCAR. Those built by Russian Hams and were mostly called Radiosputnik. In order to build and launch the satellites AMSAT needs members and friends to contribute and raise funds. If you are not yet a member of AMSAT please consider to join us and to support the activities. You can find several links to AMSAT on my links page.

My special thanks to Roy W0SL, Jim N4ST, Don KD4APP, Darrel AA7FV, Jim N5JDB, Clive G3CWV, Mike My special thanks to Roy W0SL, Jim N4ST, Don KD4APP, Darrel AA7FV, Jim N5JDB, Clive G3CWV, Mike DK3WN, Reinhard DJ1KM +, Michael DG1CMZ, Oliver DG6BCE, Peter DF2JB, Volker DF7IT, Jean-Louis F6AGR, Thomas HB9SKA, Christoph HB9HAL, Claudio IK1SLD, Andreas OE1DMB, Michael PA3BHF, Henk PA3GUO, Darek SP9TTX, Ricardo PY3VHQ, Keith ZS6TW, Don N4UJW, Vladimir RA3DQT, Paulo CT1ETE, John KD2BD, Harald DH8HHA, Maik Hermenau, Ian ZL1AOX, Gerd DL8DR, Michael OH2AUE, Robert G8ATE, Wouter Jan Ubbels PE4WJ, Mark KF6KYI, Al W8KHP, Drew KO4MA, Rolf DK2ZF, Dave WB6LLO, Graham G3VZV, Joe K0VTY, Nils von Storch, Zeljko 9A2EY, Pierre ZS6BB, Bent OZ6BL, Mariano CT1XI, Al GM1SXX, Luc LU1FAM, Matt SQ7DQX, Lance K6GSJ, Chris VK3AML, Bob VE6BLD, Sergej RV3DR, Alex VK5ALX, Rudolf ZS6FX, Dick Daniels W4PUJ/SK , Bob Patterson K5DZE, Jean-Louis Rault F6AGR, Ivano Bonesana, Patrick Hajagos, Luc Leblanc VE2DWE, Mike N1JEZ, John K6YK, Tetsu-san JA0CAW, Marco Bauer, Carl Lindberg SM6NZV, Philip G0ISW, Kuge-san JE1CVL, Pat AA6EG, John M0UKD, Paul Marsh M0EYT, Federico Manzini, Jan PE0SAT, Domenico I8CVS +, Roland Zurmely PY4ZBZ, Rob Hardenberg PE1ITR, Michael Kirkhart KD8QBA, Davide D'Aliesio IW0HLG, Francisco EA7ADI, Kubota-san, Noguchi-san JA5BLZ, Kuge-san JE1CVL, Luciano PY5LF, Wakita-san JE9PEL, Peter ON4EZJ, Enrico IW2AGJ, Jean-Pierre F5YG, Remco PA3FYM, Dave G0CER, Jose Maria EA2JX, Viljo ES5PC, Charly DK3ZL, Bernd DL6IAN, Gustavo LW2DTZ, Juergen DL8SDQ, Gary ZS6YI, Wilhelm DL6DCA, Bence Szabo, Alex KR1ST and Branko 9A3ST for kindly contributing to this collection !




Launch Date

MIR Space Station

Another way to use large space objects is to use them as passive reflectors. MIR indeed was large enough to scatter enough signal back to Earth. The audio file enclosed was recorded by Jean-Louis F6AGR on Feb. 21st 2001. He received CW (morse code) signals, which were transmitted on 144 MHz by F6ETI.

Feb 20th 1986

Fuji OSCAR 12

FO-12 (JAS-1A) was developed by Japan Amateur Radio League with system design and integration done by NEC. It was launched aboard a H-I launcher piggyback with a Japanese experimental geodetic satellite Ajisai (EGS). Its circular orbit (1490km) was inclined by 50 degrees. It featured analog (JA) and digital (JD) transponders with uplink frequencies in 2m band and downlink frequencies in 70cm band (output power was 1 Watt). FO-12 operated until November 5th 1989 when the batteries failed.

Aug 12th 1986

I am searching for sound files. Please send them to

RS 10/11

RS-10 and RS-11 were tandem loads integrated into a navigation satellite called Cosmos 1861. This satellite was launched into a circular orbit with an altitude of 996 km and an inclination of 83 degrees. RS-10 and RS-11 supported the following modes: A, K, T, KA and KT with an output power of 5 Watts.

Jun 24th 1987

RS-10 in Robot mode, AA3O transmitted in CW on the 2m uplink and the satellite responded with a QSO# on the 10m downlink, recorded by N4ST (ex AA3O)

RS-11 CW telemetry signal on 10m downlink recorded by Jim N4ST

RS-11 in Robot mode, QSO of KD2BD on March 6th 1988. John used an 2m FM transmitter which he keyed to generate a CW signal. Recording kindly provided by John KD2BD.


AO-13 was launched on June 15th 1988 on an Ariane-4 rocket from Kourou/French Guiana. It was at its time the most powerful Amateur Radio communications satellite. AO-13 was in a highly elliptical orbit, which provided the spacecraft outstanding DX potential over the world's most populated regions (Asia, North America and Europe).
AO-13 carried four beacon transmitters and four linear transponders. The beacon downlinks were:
Mode V (General beacon): 145.812 MHz CW/RTTY/PSK
Mode V (Engin. beacon): 145.985 MHz PSK
Mode U (General beacon):435.652 MHz PSK
Mode S (Engin. beacon): 2400.664 MHz PSK
The most used transponders were:
Mode U/V (B) Linear Transponder (Inverting):
    Uplink: 435.573 - 435.423 MHz LSB/CW
    Downlink: 145.825 - 145.975 MHz USB/CW
Mode V/L/U Linear Transponder (Inverting):
    Uplink: 2m SSB/CW
    Uplink: 23cm SSB/CW
    Downlink: 70cm SSB/CW
Mode U/S Linear Transponder (Inverting):
    Uplink: 435.602 - 435.638 MHz LSB/CW
    Downlink: 2400.711 - 2400.747 MHz USB/CW
In November 1998, after 8 years of operation, the solar panels failed as they got very hot during low perigee passes in the dense atmosphere. The plot enclosed shows such a transition recorded on November 23rd 1998 in orbit 6479. AO-13 finally decayed on December 5th 1996.

Jun 15th 1988


The first ZRO test (in memoriam of K2ZRO) was conducted via AO-10 on May 5th 1985 at 11:30 UTC in Mode B (145.850 MHz downlink). From then on ZRO tests were regularly conducted on AO-10 and later also on AO-13. During these tests a Morse signal with decreasing power level was transmitted and thus allowed the user to evaluate the performance of his receiving system. Enclosed you can hear the ZRO transmission on 145 MHz via OSCAR 13 from Andy MacAllister, on 24 April 1993. The file contains about 6 minutes of continuous data, starting with ZRO level 8 data, (24 dB below the beacon) including the level 9 (-27 dB) and level A (-30 dB) signal, finishing with the "End of test" message at full power. Recorded by Darrel AA7FV.

On April 11th 1989 Dave WB6LLO recorded the 2m PSK beacon which transmitted at 400BPS. The mp3 files are smaller in size and thus quicker to download. However I added also wav files in case someone wants to use them to test his telemetry decoder.

On April 11th 1989 Dave Guimont WB6LLO recorded the Mode-B (2m) downlink of AO-13 with several SSB signals.

Here is another station calling WB6LLO but he is missing the "B" in his callsign. Recorded also in April 1989 (AO-13 Mode B orbit #633) by Dave WB6LLO.

QSO of CT1BQN and JA4EV on AO13. Recorded by Darek SP9TTX (this complete QSO is 4 MBytes large).


UoSAT OSCAR 14 was launched together with UoSAT OSCAR 15 from Kourou on the Ariane flight V35 ASAP into a sun-synchronous orbit (hight 780km, inclination 98 degree). The primary payload of this Ariane launch was SPOT-2.
The primary purpose UO-14, a 46kg 3-axis stabilized satellite, was a digital Store and Forward communications transponder supporting multiple access from hundreds of portable groundstations. It was particularly suited to communications in remote or disaster-stricken areas. Two experimental payloads were included to monitor the radiation environment experienced by the satellite in Low Earth Orbit (LEO), measuring cosmic particles, and total radiation dose.
UoSAT-OSCAR14 spent its first 18 months in orbit operating as an amateur store and forward satellite. In early 1992, all amateur operations were moved from UO-14 to UoSAT-OSCAR 22. UO-14 operations were then dedicated for use by VITA (Volunteers In Technical Assistance) who used it for sending and receiving messages escpecially medical data transmissions in Africa (service was called also Satelife and UO-14 was renamed to Healthsat-1). When the computer used for store and forward communications became non-operational, in March 2000 UO-14 was re-configured as a very popular single channel FM repeater in space. Frequencies used were:
Uplink:      145.975 MHz (9600 bps FSK AX.25) or analog FM
Downlink: 435.070 MHz (9600 bps FSK AX.25) or analog FM
Beacon:    435.070 MHz (1200 bps AFSK (NBFM) AX.25)
UoSAT-3 was taken out of service in August 2003 due to insufficient power from the rechargeable batteries which lost their capacity.

Jan 22nd 1990

QSOs of DL1LSZ and F6HCC using the FM repeater mode on February 25th 2002, recorded by DK3WN

Multiple QSOs of Don KD4APP on May 19th 2002.


UoSAT OSCAR 15 was launched together with UoSAT OSCAR 14 from Kourou on the Ariane flight V35 ASAP into a sun-synchronous orbit (hight 780km, inclination 98 degree). The primary payload of this Ariane launch was SPOT-2.
The RF system on UoSAT-4 consisted of three VHF receivers and two UHF transmitters. During normal operation all receivers were active and one downlink could be selected via a telecommand operated relay. Up and down link data rates were 1200 AFSK and 9600 FSK, though only 1200 AFSK was used during the commissioning phase. The transmitter output power was set to 1.5 watts during acquisition could have be switched up to 5 Watts.
UoSAT-4 failed 30 hours after launch, thus most likely no recordings of its transmissions are available.
I am searching for sound files. Please send them to

Jan 22nd 1990


PSK signal recorded by DK3WN

Jan 22nd 1990

1200Bd Manchester coded FM signal recorded by DK3WN

Recorded by Don Woodward, KD4APP, Oct 5th 2002

SSB downlink signal received by Mark KF6KYI on February 23rd 2008.

Dove OSCAR 17

DO-17 included a Digital Orbiting Voice Encoder. Please listen to the enclosed synthesized voice message.

Jan 22nd 1990

This recording was done during a DAC test transmission.

The 1200Bd AFSK signal was recorded by DK3WN

The 2.4 GHz downlink carrier of AO17 shows a strong doppler shift. Recorded by OH2AUE.

Weber OSCAR 18

Sporting a full-color CCD camera, WEBERSAT OSCAR-18 digitized Earth images and downlinked them on 70cm as AX.25 serial data streams. It also featured a packet radio mailbox facility.
I am searching for sound files. Please send them to

Jan 22nd 1990

LuSat OSCAR 19

CW beacon on 437.125 MHz recorded August 9th 2002 by KD4APP

Jan 22nd 1990

BPSK downlink (sporadic) recorded April 29th 2003 by KD4APP

CW signal received on 437.125 MHz in FM mode by Mark KF6KYI on January 20th 2008.

CW signal received on 437.125 MHz in CW mode by Mark KF6KYI on January 28th 2008.

The LUSAT-1 CW beacon on 437.125 MHz quit transmitting in December 2012 after 23 years of operation. From thereon only a very weak carrier from the local oscillator could be heard.

On June 9th 2013 the beacon of LUSAT-1 became operational again with quite strong signals being received by radio amateurs the around world. Modulation is CW without a Morse logic, just some dots, regular spaces and sometimes a dash.

Fuji OSCAR 20

FO-20 was the successor of FO-12. The 50 kg satellite was launched by NASDA in Japan into an elliptical orbit with a perigee of 912km, an apogee of 1745 km and an inclination of 99°.

Feb 7th 1990

QSO DL1LSZ and G7RVM on March 17th 2002 16:02UTC recorded by DK3WN (ex DL1LSZ)

Weak beacon signal recorded September 6th 2002 by KD4APP, A0 test, changes in tone is generated by Don's UniTrac control system changing the doppler

Rudak 2
Radiosputnik 14
RS 14
Radio M-1

This satellite was a joint venture between the AMSAT organizations in Russia and Germany. The amateur equipment rode piggyback on a Russian experimental geological satellite (INFORMATOR-1). The joint project was called Radio M-1 by the Russian team (amateur radio satellite club Orbita and the Adventure Club of Moscow) respectively Rudak-2 by the German hams (at Marburg, Munich and Hannover). The collaboration led to dual names for the new amateur radio satellite once it arrived in orbit: AMSAT-OSCAR-21 (AO-21) and Radiosputnik-14 (RS-14).
AO-21 was a very successful and popular satellite as the 4 different receiving channels in the 70cm band supported multiple modes. The computer could generate differently modulated signals (BPSK, AFSK, FSK, RSM, FM) and thus eight different modes could be transmitted:
- 1200 bps, BPSK, NRZI (Fuji mode)
- 400 bps, BPSK, Biphase s, (Phase-3 mode)
- 2400 bps, BPSK, Biphase s, (Rudak-1 mode)
- 4800 bps, RSM, NRZIC
- 9600 bpses, RSM, NRZI + Scrambler
- CW
- FSK for RTTY, SSTV, FAX transmissions
- FM-modulated through a DSO RISC Processor

Jan 29h 1991

Test transmission of the in-orbit functional checkout of the DSP in RUDAK-2. Note at the beginning of the transmission the BPSK data transmission.

FM voice message transmission of German AATiS (Arbeitskreis Amateurfunk und Telekommunikation in der Schule) on 145.983 MHz. Recorded between Oct 15th and 31st 1993.

Voice greetings in English and German. Recorded by OE1DMB.

Voice messages in Russian. Recorded by OE1DMB.

Voice message in French. Recorded by SP9TTX.

In memoriam of the first man on the moon, which was 25 years before, AO-21 re-transmitted in 1994 the message of the Eagle-Crew as well as a SSTV picture. Sound recorded by OE1DMB, SSTV recorded by SP9TTX.

QSO of EA5ZM Artur and SP9TTX Darek. Recorded by Darek SP9TTX, September 9th 1994.

Special Christmas greeting (music) prepared by DB2OS and copied with an IC2E hand-held by Michael OH2AUE.

RS 12/13

RS-12 and RS-13 were tandem loads integrated into a navigation satellite called Cosmos 2123. Cosmos 2123 was based on the Tsikada satellite platform and was launched into a circular orbit with an altitude of 1000 km and an inclination of 83 degrees. RS-12 and RS-13 supported the following modes: A, K, T, KA and KT with an output power of 5 Watts.

Feb 5th 1991

RS12 CW robot transmission recorded by DK3WN, November 3rd 1999

Strong CW beacon signal from RS12 recorded by DK3WN, December 6th 2000

Fading CW beacon signal from RS12 recorded by Don Woodward, KD4APP, July 27th 2002

RS13 also featured a linear transponder with a 2m downlink. You can hear several stations on the enclosed recording which was kindly provided by Maik Hermenau.

Rudolf ZR6JRN (now ZS6FX) had a nice SSB contact with ZS6RY via RS-13. Recording provided by Rudolf ZS6FX.


UoSAT OSCAR 22 was launched on a Ariane 4 rocket from Kourou into a polar orbit. Beside a CCD camera experiment it also featured a packet radio store and forward mailbox. This 9600bd packet radio (AX-25) mailbox had an uplink frequency of 145.900 MHz and a downlink frequency of 435.120 MHz.

Jul 17th 1991

The S&F mailbox of UO-22 was also used to transfer pictures and voice mails. On March 22nd 1992 Peter DB2OS uploaded a message to QO-22 and received 3 answers from Jeff G0/K8KA, Ong G7JNV and Hans G7GRS which you can find below. This was probably the first time voice mails were exchanged via an Amateur Radio Satellite. The voice was originally sampled with 6kHz, reduced using a 4 bit compression and encoded in VOC format. To be compatible with today's browsers I converted them to mp3 format. Unfortunately the original voice message from Peter DB2OS is lost.

Reply 1 from Jeff G0/K8KA

 Reply 2 from Ong G7JNV

Reply 3 from Hans G7GRS

Audio recordings kindly provided by Peter DB2OS.

KitSat OSCAR 23

KitSat OSCAR 23 was a store and forward AX-25 packet radio satellite built as joint project by Korean Advanced Institute of Technology and British University of Surrey. The 9600bd uplink frequencies in the 2m band were on 145.850 MHz and 145.900 MHz. The 9600bd downlink frequency was 435.175 MHz. Normally the 9600bd downlink sounds like noise. However during a malfunction on March 3rd 1999 at 08:10UTC Mike DK3WN recorded this unique downlink signal.

Aug 10th 1992

Arsene OSCAR 24

Arsene OSCAR 24 was launched on May 13th 1993 on an Ariane V-56A rocket from Kourou into an equatorial elliptical orbit. AO-24 was built by French Radio Amateur Club de l'Espace and featured a Mode B as well as a Mode S transponder. The Mode B transponder failed soon after launch and thus the 145.975 MHz downlink (1200 bps FM AFSK) was never used. However Arsene OSCAR 24 could be used for several months as a SSB / CW linear transponder with the Mode S downlink at 2446.54 MHz.until this transponder failed as well. In the audio file enclosed you can first hear the telemetry downlink, then JA3GCT calling CQ and finally a QSO of HB9HAL and I6CGE. All recorded on the S-Band downlink on August 7th 1993 by Christoph HB9HAL.

May 12th 1993

KitSat OSCAR 25

KitSat OSCAR 25 was launched on Sepember 26th 1993 together with 3 other Amateur Radio satellites on an Ariane 4 rocket from Kourou into a polar orbit with 98° inclination. This successor of KO-23 included a CCD camera and multiple other experiments. KO-25 is a store and forward AX-25 packet radio satellite using 9600bd FSK in up- and downlink. The uplink frequencies are 145.870 MHz and 145.980 MHz, the downlink frequency is 436.500 MHz.

Sep 26th 1993

The downlink signal of KO-25 in the 70cm band was recorded by Don Woodward, KD4APP, on Sept 7th 2002


Launched on an Ariane 4 rocket the mission of IO-26 was to store and forward amateur radio messages . Its signal was recorded by Don Woodward, KD4APP, on Nov 14th 2002

Sep 26th 1993

This PSK downlink signal was recorded by DK3WN

Amrad OSCAR 27

EYESAT-1 was built by AMRAD (Amateur Radio Research and Development Corporation). It was one of six satellites that were launched together on a Ariane V59 rocket from French Guiana. Once in orbit and operational the amateur payload of EYESAT-1 was designated AMRAD-OSCAR 27. AO-27 features a Mode V/U (J) FM Voice Repeater. The uplink frequency of this bent pipe FM repeater is 145.8500 MHz (FM), the downlink frequency is 436.7950 MHz (FM). This satellite can be worked with simple FM equipment and was also successfully tested with D-Star.

Sep 26th 1993

QSOs of DL1LSZ and DL2DRD on December 4th 1999, recorded by DK3WN

QSOs recorded by Don Woodward, KD4APP, Sept 8th 2002

John K6YK had a contact with Greg WB6FZH/KH6 via AO-27. Recording kindly provided by John K6YK.

1200bd Telemetry recorded by Don Woodward, KD4APP, Nov 19th 2002

Usually analog FM voice transmissions are used via AO-27. However the new DSTAR standard which is intended to be used via terrestrial FM repeaters can be also used via satellite as the test transmission of Luc Leblanc VE2DWE demonstrates. He used an ICOM IC2200 TRX for the 436.795 MHz downlink and a ICOM ID-800H for the 145.850 MHz uplink. Recorded on September 5th 2009 at 22:49 UTC and kindly provided by VE2DWE.

After 16 years in orbit AO-27 was still operational. Enclosed downlink signals on 436.797 MHz were recorded on March 14th 2010 at 12:21 UTC by DD1US using an omnidirectional antenna.

PoSat OSCAR 28

First Portuguese Amateur Radio satellite. It was launched on a Ariane V59 rocket from Kourou. The launch included the German Stella Laser Reflector, Healthsat-II, KITSAT-OSCAR-25 (KO-25), Italy-OSCAR-26 (IO-26), Amrad OSCAR 27 (AO-27) and PoSAT-1 (PO-28).

I am searching for sound files. Please send them to

Sep 26th 1993

RS 15

CW telemetry signal recorded by DK3WN, Sept 19th 2002 13:40UTC

Dec 26th 1994

Weak CW beacon signal from RS15 on 29.352 MHz recorded by KD4APP, Sept 30th 2002

On June 14th 2009 at 08:20 UTC Henk PA3GUO recorded the CW beacon of RS15.




Launch Date

If you have further recordings from space objects please let me know. I will be happy to add them to my homepage. Many thanks in advance.

Vy 55 & 73 de Matthias DD1US               

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