I am looking for a #217 Ten Tec 500 Hz crystal filter for use in the narrow slot on my Omni V. It has the 250 Hz filter which is a bit too narrow for use on VHF CW. I am using the Omni V with a transverter on 6 meters. I could buy the filter outright, or swap the 250 Hz one for it, too. 73, Steve WA9JML