E F Johnson low pass filter for sale: 52 ohms impedance, Catalog number 250-20. This is the cylindrical filter, with an SO-239 connector on each end. It even has its brackets for mounting it to the wall still with it. $ 30 plus shipping from Florida. Thanks. 73, Ken, W8EK Ken Simpson E-mail to [email protected] or [email protected] Voice Phone (352) 732-8400