Satellite Communications
One of my favourite aspects of amateur radio,(other than being a "white noise junkie" - i.e 6M 50Mhz fan) is using the FM satellites. AO-51 SO-50 and AO-27 are very user friendly and can be worked with a dual band hand held radio. I use my FT-817ND and a home made version of the commercial arrow antenna, I also use a Palm IIIe PDA to run PocketSat+ satellite tracking software. AO-51 in the photo to the right is probably the easiest amateur satt to make a contact through, I have made many contacts using only 0.5W output power although I usually use 2.5W.
The
aerial I use is half of a 19 element Tonna for 70cms (432Mhz) with three
elements for 2m (144Mhz) made from a retractable tape measure, mounted at 90deg
to the 70cms elements. I do not need to use a duplexer for the two aerials as I
feed the aerial halves from the front and rear aerial sockets on the FT-817ND.
To compensate for the doppler shift as the satellite passes overhead, I have
frequencies programmed into the memories of the FT-817 for acquisition of
signal, before mid-pass, mid-pass, declination and loss of signal. If you wish
to programme your radio similarly, I have put the frequencies for the common FM
satts into a spreadsheet. Click here
to download.
In QSO with OZ1MY at 1923UTC 9th July 2007
Current amateur satellite status.