Tuesday, September 4, 2012

KP4AO: Our first EME experience

On April 17, 2010 a small group of operators (EA4AAE, EA4EOZ, EB4EMM and EB4GLE) prepared a quick and dirty station to "try" to work KP4AO via moon, who was operating the impressive 300 meters radiotelescope at Arecibo.

 The station consisted on:
  • Tonna 19 elements for 70cm band
  • No antenna preamplifier
  • 5 meters of 1/2" coaxial cable
  • Icom IC-910 ( 75W output )
And this is what we received:

Signals were weaker than expected. Signals had a very strong QSB, being perfectly readable for few seconds every minute or so. We made a few calls, but obviously, no answer.

Fortunately KP4AO team did some wideband recordings using a SDR receiver, and they put them on the Internet. After downloading the huge files (1GB each) and synchronize them with out own recordings, we were able to localize the file recorded when we was calling KP4AO.

The question was: Will we find our calls in the recording? After almost a week looking deep into the file using SpectraVue, we were able to localize our calls, received by the big dish:

As you can hear, weak but readable signals. They would be successful in a sked, but too weak for go through the BIG pile-up. Anyway, not bad for such simple installation, isn't it?

After this small (but very exciting) step, I'm sure we will improve our small station to do real two way EME with some big gun soon.

No comments:

Post a Comment