ISS ARISS Packet Operations with the D700

On August 31, 2003 A new radio from the company Kenwood Company arrived on the International Space Station. The radio is a Kenwood TM-D700 Amateur Radio transceiver which arrived via the Progress 12P Rocket. This radio supports both Voice modes and Packet modes and includes a built-in modem for packet operations. On December 8 2003 the Kenwood TM-D700 was installed in the ISS module called the Zvezda Service Module and has been in operation ever since.  This radio has been used extensively for hundreds of pre-arranged schools schedules, and thousands of random voice contacts with Amateur Radio stations around the world.  When the system is not being used for Voice operations, it is usually placed in the Packet mode, which will be discussed on these pages.  In August and September of 2006, the D700 was successfully used with the MarexMG SpaceCam Slow Scan TV system.

Note:  Most of the Packet manuals were written for the original ISS packet system using the PacComm TNC.  There is a link at the bottom of this page which describes some of the differences.

ISS Packet Mail box call sign for   D700:  RS0ISS-11
ISS Packet Beacon call sign for D700:  RS0ISS-4
ISS Packet Keyboard call sign for D700:  RS0ISS-3 (not used)
ISS Packet Unproto call sign for    D700:  ARISS

ISS ARISS D700 Packet Examples and Quirks

The D700 has the equivalent of two radios in one box (called Left and Right).  Normally you use one radio for TX and RX, and the second radio is used for receiving.  Then by pushing one button you can switch to the other radio for transmitting and receiving.  The radio on ISS has been programmed to use Both transceivers at all times in a cross connected configuration.  When the D700 is in Packet Mode, it will Transmit Packet data on the Left Side Radio and Receive packet Data with the Right Side radio. At the same time, it is listening for Voice Audio with Left Radio and ready to send (Transmit) Voice on the Right Radio. This unusual setup required some unique software configurations that are not used with Terrestrial versions of the D700. The cross radio configuration  has caused some interesting Quirks with the packet system (Unproto/APRS and Packet Mail), including long 10+ second packet delays with this system.  

In September 2007 the D700 was manually reprogrammed to disable to cross radio configuration.  There was in immediate improvement in packet radio performance.  The 10+ second long delay was finally gone.  The ARISS team is currently working on a finalizing a new version of software for later in 2008.



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