Hello, There is a good description of 'Jansky's merry-go-round' with some beam patterns at: http://www.gb.nrao.edu/~fghigo/JanskyAntenna/RepeatingJansky_memo10.pdf It looks like the counterpoise was original. It was a great weekend: I saw and learned so much. It was good to meet new and old friends too. Well worth the trip across the Atlantic. Brian Hawes G2KQ