Funcube

My contribution to the Funcube project is to put myself in the place of a sympathetic science teacher who isn't necessarily a radio amateur.

I set up my station as follows:

  • No rotator. I previewed the azimuth of maximum elevation on both amsat.org and n2yo's website and pointed the antenna there.
  • A Funcube Dongle Pro Plus
  • Win 7 laptop
  • Latest Dashboard software
  • A small single transistor rf preamp for 2 metres  mounted at the Yagi - the one from the RSGB VHF handbook I used for ARISSAT-1 and a battery in the garden.

I think the Yagi is the only complex part of the above and could be manufactured easily.

I then spent some time securing everything against cable fractures and water ingress. For the preamp I used a plastic water cup, inverted, to allow runoff, as I had read many years ago in the excellent book by Davidoff.

Then - nothing!!

After checking all the cables I looked at the signal using the waterfall function of SDR sharp.

At first I looked at a known D-Star signal on 144.8125 (Fig 1 below).


To my surprise, the signal which i knew was on 144.8125 was showing on  144.770!

So, I reasoned, the Dongle was actually set to (144.8125 - 1444.770) = about 40 kHz lower than the software said!

Therefore I went to the FCD Dashboard and set the centre frequency to 145.900 , knowing that the signal was actually 145.935.


As you can see above, the signal popped up on the correct frequency, 145.935!
 The automatic tracker found it and the telemetry followed.


The moral of his story is: CHECK EVERYTHING! And another one - DON'T BELIEVE THE SOFTWARE!