"Just DO the common mode choke on any vertical. Don't tempt Murphy."
I stand by my comments. I find after some interesting conversations that readers of posts often read as if written to them. So I write my posts as to the general audience. If an expressed situation is so specific as to be exceptional to general use, I reply in private. *Of course* there will be a few situations where this general purpose rule won't add any value. The question is whether a specific owner has the equipment and technical knowledge to identify those situations, which are highly specific and subject to all kinds of local influences, and whether one can post a textbook to explain the choices. And while theoretical situations are raised, I continue to this day finding situation after situation where a vertical needs common mode blocking to help fix it, and I've not ever once had to tell someone to REMOVE a common mode choke at a vertical feedpoint. I was speaking of vertical feedpoints. Dipoles are another subject. 73, Guy. _______________________________________________ Remember the PreStew coming on October 20th. http://www.kkn.net/stew for more info.