Converter needed

Hi, I build amateur radiotelscope for 4GHz. I wish it would be an interferometer, but I have only 1 converter. It’s Strong SRT LC970 C-Band and I need the second one (the same model), because it has really good parameters. I thought this one is quite popular, but now I can’t find them in any shops. Maybe some of you has that converter, don’t need it and could sell it to me? Or maybe you know any shop where I can buy it? I’ll be very thankful for any information, as this case is really important for me