[amsat-bb] Re: FUNcube + SatPC32 + SDR-Radio
m5aka at yahoo.co.uk
Tue Aug 28 02:39:46 PDT 2012
--- On Tue, 28/8/12, Thomas Doyle <tomdoyle1948 at gmail.com> wrote:
> The activity level on the linear sats is very low and does
> not seem to be getting any better. Not sure why.
Possibly a couple of factors
- In 2003 the Morse requirement for HF operating was dropped in the UK and elsewhere (USA 2007). Until then the majority of radio amateurs in many countries had to operate on VHF or UHF only. With the removal of the code test they moved to HF as have all new amateurs since that time, with occasional usage of VHF/UHF FM for local chats.
- Limited range of some Linear Transponder Satellites. Orbits below 1000 km don't allow for DX working and have limited pass times and higher Doppler shift. When OSCAR-8 was launched into a 900 km orbit it was no-where near as popular as OSCAR-7/6.
The orbit is the key. Fold-out solar panels, such as that used on NEE-01 Pegasus, mean a CubeSat can support a linear transponder running 2 or 3 watts but currently affordable orbits are only in the 500-800 km range. We need to develop the means to boost the orbit of a CubeSat up to say the 2000 km used by RS-15.
73 Trevor M5AKA
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