Latest revision as of 14:31, 11 October 2025

HAMTV is the name of the Digital Amateur Television (DATV) transmitter on board the Columbus module of the International Space Station (ISS). It is a DVB-S digital audio and video transmitter, normally on 2395MHz (13cm band).

The HamTV unit was first installed on the ISS in 2013, commissioned in April 2014 and was used for a number of ARISS school contacts in 2016 - 2018. The unit failed in 2019, and was brought back to earth for repair. It was returned to the ISS on the SpaceX SpX-30 flight on March 21st 2024. It was finally installed and first powered on again on 29th July 2025.

Purpose

The primary use of HAMTV is for ARISS schools contacts, when the astronaut will use a camera to show live video of himself and the inside of the ISS to the school during the VHF radio contact.

Outside of school contacts the transmitter is often left switched on to enable experimentation and self-education in the building of ground stations.

Transmission Details

Whilst the transmitter has a number of possible configurations, it is anticipated that most transmissions will be:

2395 MHz, RHCP, 2W power at the patch antenna pointing down from the ISS.
Modulation: 2.0 Msymbols/second, DVB-S (QPSK), FEC 1/2
Content: MPEG-2 video with MP2 audio.

More details can be found at: HAMTV from the ISS - HAMTV Transmitter Information

How can I watch HAMTV? (without a ground station)

A network of ARISS ground stations contribute to a central feed using the BATC Merger to enable high-quality reception for School Contacts. You can watch the video output whenever ground stations are receiving the signal.

ARISS / BATC HAMTV Ground Station Network: https://live.ariss.org/hamtv/

How can I build my own ground station to receive HAMTV?

Building a ground station to receive HAMTV from the ISS is challenging.

The link budget is a lot less forgiving of non-optimal stations than VHF/UHF, the high 'microwave' frequency brings lots of pitfalls, the equipment can be expensive and/or hard to source, and the limited visibility and fast movement of the space station across the sky can make it time-consuming and frustrating to troubleshoot any problems that occur.

The result however is being able to receive live video from an Astronaut (during school contacts), with your own S-band ground station! You could also talk to ARISS Ops about joining the ground station network and using your antenna to contribute directly to School Contacts.

Components of a typical ground station

Antenna - Typically a dish of 0.6-1.2 meters in diameter, with a helix or patch feed.
Pointing Mechanism - to follow the ISS across the sky. Can be motorised, or manual for smaller antennas.
LNA - Required, and mounted as close as possible to the antenna feed to minimise coax loss at microwave frequencies.
Filter - May be required to prevent overload if you have strong WiFi (2400MHz+) or 5G (2380MHz-) nearby.
Downconverter - Optional, allows use of non-microwave capable receivers, also reduces loss in long coax runs.
Receiver - Needs to be capable of receiving 2.4MHz-wide DVB-S. A good receiver can be more tolerant of issues elsewhere in the ground station.

For more information read: HAMTV from the ISS - How to build a ground station

Can I help support HAMTV downlinks for ARISS Educational Contacts?

To assist our volunteer teams with providing a reliable HAMTV experience for the participants at Educational Contact events, a Ground Station Merger facility has been developed to crowd-source the HAMTV data in realtime from geographically diverse ground stations.

Before getting involved you'll need to have a reliable station up and running, however there are also some requirements on the equipment involved that can be found at the link below.

HAMTV from the ISS - How to contribute to the ARISS Merger

Social media

ARISS international on Twitter/X: https://twitter.com/ARISS_Intl

ARISS International on Bluesky: https://bsky.app/profile/arissintl.bsky.social

Join and ask questions in the ARISS Discord: https://discord.gg/dQUEE48C

BATC forum

BATC have setup a new forum thread to discuss receiving HamTV.

Please post any questions, comments and status updates here: https://forum.batc.org.uk/viewtopic.php?f=2&t=8398

A lot of information is available on the BATC forum: https://forum.batc.org.uk/viewtopic.php?t=4389

Relevant Presentations and Video

Colin G4KLB on how he received HamTV in 2014: YouTube

Video of HamTV in action during the Tim Peake Principia mission contact with Norwich schools in 2016: YouTube

G8GTZ on receiving HAMTV at the AMSAT UK conference in October 2023: YouTube

Next generation HamTV presentation by Phil M0DNY at the AMSAT UK conference in October 2023: YouTube

HamTV Ground Stations presentation by Phil M0DNY in October 2024: [ YouTube (coming soon)] Slides

Comments on this wiki page

If you have any comments on this wiki page or if you think we should add more information to it, please email them to wiki @ batc.tv

@@ Line 1: / Line 1: @@
-The original HamTV unit was installed on the ISS in 2013 and commissioned in April 2014 and was used for a number of ARISS schools contacts in 2016 - 2018. The unit failed in 2019 and was shipped back to Kaiser Italia for repair.
+__NOTOC__
+[[File:HAMTV 1.jpg|400px|right]] HAMTV is the name of the Digital Amateur Television (DATV) transmitter on board the Columbus module of the International Space Station (ISS). It is a DVB-S digital audio and video transmitter, normally on 2395MHz (13cm band).
-[[File:HAMTV 1.jpg|400px|]]
+The HamTV unit was first installed on the ISS in 2013, commissioned in April 2014 and was used for a number of ARISS school contacts in 2016 - 2018.
+The unit failed in 2019, and was brought back to earth for repair. It was returned to the ISS on the SpaceX SpX-30 flight on March 21st 2024. It was finally installed and first powered on again on 29th July 2025.
+== Purpose ==
-Following repairs carried out last year it now looks likely that the original HAMTV unit will be returned to the ISS with potential commissioning by a visiting astronaut during Spring 2024.
-==What is HamTV==
+The primary use of HAMTV is for ARISS schools contacts, when the astronaut will use a camera to show live video of himself and the inside of the ISS to the school during the VHF radio contact.
-HAMTV is the name of the Digital Amateur Television (DATV) transmitter on board the Columbus module of the International Space Station (ISS).
+[[File:HAMTV 2.jpg|400px]]
-[[File:HamVideo1.jpg|400px]]
-It transmits Digital video and audio in MPEG-2 format using the DVB-S protocol in the 13cms band.
-===HAMTV specifications===
-====Ham Video downlink frequencies====
+Outside of school contacts the transmitter is often left switched on to enable experimentation and self-education in the building of ground stations.
-*2395 MHz (main operating frequency)
-*2369 MHz
-*2422 MHz
-*2437 MHz
-====DVB-S modulation====
+== Transmission Details ==
-*Symbol rates: 1.3 Ms/s and 2.0 Ms/s
-*FEC : ½
-====RF output====
+Whilst the transmitter has a number of possible configurations, it is anticipated that most transmissions will be:
-The HAMTV transmitter produces 10 watts RF, however this is then fed through a series of interconnecting cables and bandpass filter before passing through the ISS Columbus module external wall.  Estimated power at the antenna is ~ 2 watts.
-====HAMTV antenna====
+* 2395 MHz, RHCP, 2W power at the patch antenna pointing down from the ISS.
-The HamTV transmission runs relatively low power on 2395MHz to a simple patch antenna on the ISS.
+* Modulation: 2.0 Msymbols/second, DVB-S (QPSK), FEC 1/2
+* Content: MPEG-2 video with MP2 audio.
-[[File:HamTV patch.png|400px]]
+'''More details can be found at: [[HAMTV from the ISS - HAMTV Transmitter Information]]'''
-This patch antenna is located on the earth side of the ISS but is surrounded by solar panels, thermal radiator panels, two or more visiting vehicles and robotic arms.
+== How can I watch HAMTV? (without a ground station) ==
-The ISS also “flies” slightly nose down to protect the cupola windows from space debris and so the RF performance, particularly when it is rising from the west, is slightly unpredictable.
+A network of ARISS ground stations contribute to a central feed using the BATC Merger to enable high-quality reception for School Contacts. You can watch the video output whenever ground stations are receiving the signal.
-The transmissions are right hand circular polarised (RHCP)
+'''ARISS / BATC HAMTV Ground Station Network: https://live.ariss.org/hamtv/'''
-====Video format====
+== How can I build my own ground station to receive HAMTV? ==
-*NTSC
-*SIF resolution: 352×240 or D1:720×480
-==What is HAMTV used for?==
+Building a ground station to receive HAMTV from the ISS is challenging.
-The primary use is during ARISS schools contacts, when the astronaut will use a camera to show himself and the inside of the ISS during the VHF radio contact.
+The link budget is a lot less forgiving of non-optimal stations than VHF/UHF, the high 'microwave' frequency brings lots of pitfalls, the equipment can be expensive and/or hard to source, and the limited visibility and fast movement of the space station across the sky can make it time-consuming and frustrating to troubleshoot any problems that occur.
-[[File:HAMTV 2.jpg|400px]]
-It is hoped that test patterns, including JPEG images, will be transmitted when the cameras are not in use.
+The result however is being able to receive live video from an Astronaut (during school contacts), with your own S-band ground station! You could also talk to ARISS Ops about joining the ground station network and using your antenna to contribute directly to School Contacts.
-==When will HAMTV be "on the air"?==
+=== Components of a typical ground station ===
-It is unlikely that the HamTV transmitter will be on air 24/7.
+* Antenna - Typically a dish of 0.6-1.2 meters in diameter, with a helix or patch feed.
+* Pointing Mechanism - to follow the ISS across the sky. Can be motorised, or manual for smaller antennas.
+* LNA - Required, and mounted as close as possible to the antenna feed to minimise coax loss at microwave frequencies.
+* Filter - May be required to prevent overload if you have strong WiFi (2400MHz+) or 5G (2380MHz-) nearby.
+* Downconverter - Optional, allows use of non-microwave capable receivers, also reduces loss in long coax runs.
+* Receiver - Needs to be capable of receiving 2.4MHz-wide DVB-S. A good receiver can be more tolerant of issues elsewhere in the ground station.
-During the first flight on the ISS between 2014 and 2018 it was used primarily for ARISS schools contacts but transmitter was left on at other times but no video was transmitted.  This did allow groud stations to test their receive equipment and it is hoped a test signal generator will be included when it is re commissioned in 2024.
+'''For more information read: [[HAMTV from the ISS - How to build a ground station]]'''
-Once re-commissioned it will be tested before contacts and will be added to the Amsat status page https://www.amsat.org/status/
+== Can I help support HAMTV downlinks for ARISS Educational Contacts? ==
-==How to receive HAMTV?==
+To assist our volunteer teams with providing a reliable HAMTV experience for the participants at Educational Contact events, a Ground Station Merger facility has been developed to crowd-source the HAMTV data in realtime from geographically diverse ground stations.
-There are a number of challenges to receive HAMTV from the ISS and a typical ground station is made up of the following elements
+Before getting involved you'll need to have a reliable station up and running, however there are also some requirements on the equipment involved that can be found at the link below.
- A typical groundstation system block diagram
+'''[[HAMTV from the ISS - How to contribute to the ARISS Merger]]'''
-===Ground station antenna===
+=Social media=
-The HamTV transmission runs relatively low power on 2395MHz to a simple patch antenna on the ISS.  This patch antenna is located on the earth side of the ISS but is surrounded by solar panels, thermal radiator panels, two or more visiting vehicles and robotic arms.  The ISS also “flies” slightly nose down to protect the cupola windows from space debris and so the RF performance, particularly when it is rising from the west, is slightly unpredictable.
+ARISS international on Twitter/X: https://twitter.com/ARISS_Intl
-[[File:dish.jpg|400px]]
+ARISS International on Bluesky: https://bsky.app/profile/arissintl.bsky.social
-This means an antenna with reasonable gain is required to receive the signal and whilst it is possible to receive the signal on a simple antenna when the ISS is overhead, to enable more than 5 minutes of reception, a higher gain antenna such as a dish with an efficient feed system is required.
+Join and ask questions in the ARISS Discord: https://discord.gg/dQUEE48C
-A 1mt or larger dish is optimum but smaller antennas such as flat plate or patch antennas will work and have the advantage of a wider beamwidth making it easier to track the ISS.
+==BATC forum==
-===Pre-amp and filter===
+BATC have setup a new forum thread to discuss receiving HamTV.
-A low noise pre-amp with band pass filter tuned to 2395MHz should be connected directly to the antenna feed point to minimise co-ax losses.
+Please post any questions, comments and status updates here: https://forum.batc.org.uk/viewtopic.php?f=2&t=8398
-Note that 2395MHz is only 5MHz below the 2.4GHz WiFi Channel 1, so good filtering will be needed to prevent WiFi from getting into the wide band satellite tuner.
+A lot of information is available on the BATC forum: https://forum.batc.org.uk/viewtopic.php?t=4389
-If you are powering the LNA at masthead up the co-ax, you will need to place the DC inseerter AFTER the filter.
+== Relevant Presentations and Video ==
-===Do I need a downconverter===
+Colin G4KLB on how he received HamTV in 2014: [https://www.youtube.com/watch?v=9keVA21DPBc YouTube]
-The HAMTV frequency on 2395MHz is outside the frequency range of a standard consumer set top box or satellite tuner.
+Video of HamTV in action during the Tim Peake Principia mission contact with Norwich schools in 2016: [https://youtu.be/DnJmxNCX4V4?si=RySuD0ft1Bcl1nTN YouTube]
-Unless you are using the BATC MiniTiouner Mark 2 or PicoTuner USB receiver equipped with the Serit 4434 NIM, which can tune up to 2450MHz, you will need a frequency down converter to place the HAMTV signal between 950 and 2150MHz which is within the range of a standard satellite receiver.
+G8GTZ on receiving HAMTV at the AMSAT UK conference in October 2023: [https://www.youtube.com/watch?v=4J_JA3Syv6Y YouTube]
- Note: The MiniTiouner Mk1 PCB with a Sharp or Eardertek tuner does NOT cover 2395MHz and will require a downconverter.
+Next generation HamTV presentation by Phil M0DNY at the AMSAT UK conference in October 2023: [https://www.youtube.com/watch?v=MQvRdG1FBo4 YouTube]
-The downconverter should be placed between the low noise amplifier and satellite receiver – placing it at the masthead will mean that lower grade feeder can be used to bring the IF signal back to the shack.
+HamTV Ground Stations presentation by Phil M0DNY in October 2024: [ YouTube (coming soon)] [https://wiki.batc.org.uk/images/c/cd/M0DNY_-_HAMTV_-_AMSAT-UK_2025.pdf Slides]
- Previous suppliers of a suitable down converter, such as Kuhne Electronics, no longer market suitable downconverters and BATC strongly recommends purchasing a new USB tuner hardware using the Serit 4334 tuner rather than building or sourcing a down converter.
+==Comments on this wiki page==
- As well as covering the HAMTV frequency without a down converter, the Serit 4334 has much better RF performance than the original Sharp and Eardertek units and has been integrated into the OpenTuner and Portsdown DATV receive systems.
+If you have any comments on this wiki page or if you think we should add more information to it, please email them to wiki @ batc.tv

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