Good info here: https://remoteqth.com/img/ZAW-WIKI/cmcc/CommonModeChokesW1HIS.pdf I live in a condo too and I had good results with ferrites. Also added a mains filter, it helps a lot. -- 73, Marco IZ2LSO -- Questa email è stata esaminata alla ricerca di virus dal software antivirus AVG. www.avg.com