Satellite Activities


I obtained my Amateur Radio License in 1960 and was given the call sign VK5ZAI. Shortly after building my first 2 metre transmitter and receiver I became interested in satellite communications. 


The first satellite that I became involved with was OSCAR-3 which was launched on the 9th March 1965.   It created a lot of excitement at the time amongst Hams and sent out "HI" in Morse, quite a simple device compared to today's standards. Back then we had to calculate the orbit passes with a pen and paper, no computers, not even a 4 function calculator but we managed.  


The antenna  I used to track it with was a twin Helix turned  manually,  a rather crude arrangement but it worked. Since then over the years I have been involved with many satellites, both voice and digital. 


In the early 1990's I got into manned space flight speaking with the crews on the Mir Space Station and the Space shuttles on many occasions, I also did 2 school linkups with the Mir Space Station and setup the phone patch for Andy Thomas during his 4 months on Mir so he could speak to his family when over Australia.   


In Nov. 2000 I was invited to join the ARISS telebridge team  (Amateur Radio on International Space Station).  This team consists of nine amateur radio stations around the world set up to support crew members wishing to speak to their family members during the mission, 3rd. party issues, or technical concerns, as well as making possible educational school contacts with the ISS. through Amateur Radio on board.

A general view of the satellite station, showing satellite tracking computer running Instant Track on the left, Transceivers, Automated Antenna Control and Phone Patch Interface in center of desk, WiNRADiO Receiver Computer on right of desk with Digital TMC's and backup Transceivers above. To the right of the operating desk is a rack which houses recording equipment, Antenna Patch Panel, Linear Amp, Packet Computer and Power Supplies.


Station Details and Photos

Click on photos below to see enlargements



The main transceiver is an FT-736R extensively modified for satellite work. A phone patch interfaces between the radio and the phone line in order to handle the ARISS telebridge commitments. An 80 watt linear Amp is pressed into service when necessary

736-winradio.JPG (83933 bytes)

Backup is an FT- 4700 dual band transceiver covering the 2 m. and 70 cm. bands.

desk.JPG (89262 bytes)

Antenna tracking and Doppler correction is controlled from a SATTRAK-3.

sattrak3.JPG (20909 bytes)


Emergency  power is handled by both battery and backup 240 volt alternator.

A new addition to the shack is an all band receiver.  In order to monitor the ISS frequencies on a continuous basis and free up the transceiver It was decided that a dedicated wide band receiver was required..........


After extensive market research I settled for a WiNRADiO WR155E computer interfaced receiver. This receiver covers from 150kHZ-1600mHz, is all mode and a pleasure to operate.  It comes with an RF Spectrum Scope that can sweep a range of frequencies. With an optional software suite it can also be used for Packet, WEFAX, HF Fax and ACARS decoding. Anyone requiring  a dedicated receiver should take a good look at these. Further details can be found at http://www.winradio.com

winradio.JPG (71733 bytes)


    For 9600 bd. I am using a PacComm NB-96 TNC. and running Wisp software on a Pentium 2 PC.  I  use Instant Track software. For voice and 1200 bd packet I sometimes use an FT-4700. with either a Baycom modem or an MFJ-1270B and on odd occasions  


The satellite antenna tracking system is home constructed and computer controlled.  The 2 m. antenna is a 10  turn  helix, 70cm. antenna is a 21 x 21 el. crossed yagi, Between them is mounted a 1.2m. diam. parabolic dish. Both have home brew pre-amps at the base. LDF-550 co-ax is used to feed the system.

antenna.jpg (61313 bytes)

return to the Index page