Amateur Radio Satellites
by Hans van de Groenendaaal
In the early days of satellites, not many years after the launch of Sputnik One in 1965, amateur satellites were designed and launched with downlinks on 29 MHz. Satellites were much larger than the present day CubeSats which only measure 10 x 10 x 10 cm and present interesting challenges for antenna design and placement.
Universities and other scientific research institutions are using portions of the amateur spectrum for their CubeSat’s which has caused the 145 and 435 MHz amateur-satellite band segments to be very crowded, leading to an increasing number of satellite builders to explore alternatives. For many, such as those requiring single-channel bandwidth greater than approximately 12,5 kHz, the best answer will be found in the microwave bands.
However, for those who can use it, the International Amateur Radio Union (IARU) satellite frequency coordination process has now opened another alternative: 29 MHz uplinks.
The use of amateur spectrum by universities and scientific research institution for their experiments is not the ideal solution and has only been agreed to by the IARU for a limited period till alternative spectrum is identified and allocated by the ITU for this purpose.
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