The original amateur radio equipment on board the International Space Station was located in the Functional Cargo Block (FGB), named Zarya. 

Phase 1 was an handheld 5 watt VHF FM transceiver connected to an outboard antenna system that supported docking of the FGB with the Russian Service Module, named Zvesda. These antennas, designed for use near the 2-meter band, no longer support docking and can be used by the ARISS team permanently.

A similar UHF handheld transceiver was on board.

For voice operation the astronauts used headphones with a microphone attached. Packet Radio was provided by means of a Modem and a portable computer. An Adapter interconnects these units.

Phase 2 Hardware was developed to have two multiband transceivers supporting 2 meter (144-146 MHz) and 70 cm (435-438 MHz) transmit/receive and L-band uplink operation. Power output is 10-25 Watts.

Together with an RF tuning unit, power supplies and a computer, the transceivers are mounted on a Velcro-backed table.

This equipment is located in the Service Module, the crew's living quarters. Four antennas were deployed by EVA (space walk) and clamped on handrails outboard the Service Module. One of the antennas is 2.5 meters long and supports HF operation.

IORS InterOperable Radio System was launched from Kennedy Space Center on March 6, 2020 on board the SpaceX CRS-20 resupply mission and installed in the ISS European Columbus module. The IORS replaced the original Phase 1 Ericsson radio system and packet module.
IORS consists of:

• JVC Kenwood D710GA transceiver VHF/UHF 25W space-modified
• multi-voltage power supply developed by ARISS

IORS operational mode is FM VHF/UHF also enabling a cross-band repeater mode. Details here

A DATV (digital amateur television) transmitter is installed in the Columbus module of the International Space Station (ISS). This transmitter is dubbed “Ham Video”.

Main characteristics :

• Downlink frequencies: 2.422 GHz, 2.437 GHz
• Contingency frequencies : 2.369 GHz, 2.395 GHz
• DVB-S like signal (without PMT tables)
• Symbol rates: 1.3 Ms/s, 2.0 Ms/s
• FEC : ½
• Video PID = 256
• Audio PID = 257
• Antennas: ARISS 41 and ARISS 43 patch antennas on the nadir of Columbus
• RF radiated power : approximately 10 W EIRP
• Ham Video operates with a Canon XF-305 camera

Commissioning

Commissioning of the Ham Video transmitter was performed April – March 2014. All four frequencies and two symbol rates were checked with each of the two antennas.

For each commissioning step, US astronaut Michael Hopkins transmitted video and audio during a pass over the Matera ground station. The Matera VLBI station is located at the Italian Space Ageny’s ‘Centro di Geodesia Spaziale G. Colombo’ (CGS) near Matera, a small town in the south of Italy.

The final commissioning test was performed by JAXA astronaut Koichi wakata, using configuration 4 for optimum results:

• 2.395 GHz
• 2.0 Ms/s

The signals were received by several ground stations and streamed to the BATC server (British Amateur Television Club). Ham TV streams are identified ISS1 – 5. The BATC server is available at http://www.batc.tv

Blank transmission

When "Blank Transmission" is operational, Ham Video transmits a continuous DATV signal with the camera turned off. Ground stations receive a black image and audio at zero level. This Blank Transmission will go on till August 6, 2014.

A « blank » DVB-S signal contains all the data of normal DVB-S. The information tables describing the content and the content itself, i.e. the video (black) and the audio (silence), are the same as for the image and the sound produced by a camera.

Receiving a black image and silent sound may seem uninteresting but, from a technical perspective, the digital signal offers an important source of information.