I once visited the second biggest Radio Telescope near my home town, and one of the there Wirkung engineers mentioned that the Green Bank telescope only got a b

I once visited the second biggest Radio Telescope near my home town, and one of the there Wirkung engineers mentioned that the Green Bank telescope only got a bigger aperture than the system at Effelsberg because the americans couldn't stand being second best, not for scientific Reasons. But I don't know if this is true or just an Urban legend.