Tuesday, October 13, 2009

Ex Luna Scientia

Well, I didn't quite make my deadline of getting it done before summer was over but now it's a done deal. This weekend, in between all the HF antenna work, I did find the time to point the VHF/UHF antenna array at the moon and make a contact. The ARRL EME Contest was running and from this far north the moon was above the horizon for the entire 48 hour period.

Like many things, I have procrastinated for months now on building a computerized antenna positioning unit. The pointing is plenty accurate for satellite work but leaves much to be desired for EME. Fortunately, it cleared up Saturday night and I could adjust the antennas by sighting the moon along the antenna booms. The ferocious winds made it difficult to keep the antennas aimed and the moon actually clips across the sky faster than you might think!

I spent quite a bit of time tuning between 144.000 and 144.100 listening for CW but didn't hear a peep. After a while I fired up the WSJT software and started looking for JT65 signals. It didn't take me long to find KB8RQ. Gary's station in Ohio has two dozen 13 element yagis with 1.5kW on VHF and Saturday night he was RUNNING stations off the moon! Of course not quite the same rate as an HF contest (it takes five minutes to complete a JT65 QSO) but he had a steady stream of callers with few unanswered CQ's. Once I had everything dialed in I could easily hear his tones in the headphones and he was registering -17dB in the software. I had only tried calling a few times when he came back to my pair of 13 element yagis and 100 watts.

I spent another hour or so after that tuning around but never heard anyone else calling CQ. I copied a few stations calling other (unheard) stations and lots of distinctive '73' tone pairs but didn't make another QSO. Hopefully this is the motivation I need to get the 2m linear amplifier built and finish the computer antenna controller!

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