I've never had a problem with roller inductors IF they are clean. They don't have to be shiny silver. Silver oxide (the dark black stuff that forms on real silver) is an excellent conductor! If it offends your sensibilities, use a tiny bit of silver polish to clean it up, but it has nothing to do with the performance of the inductor.
One end of the inductor usually connects through a rotating contact near the shaft. If that's dirty it can be intermittent too. Unless you take the roller to bits - often not practical - the best way to deal with that is to put a DROP of suitable contact cleaner on the contacts. I prefer Caig DeOxit for such things. Sometimes the mechanism that presses the roller against the turns gets sticky. Some designs use little coil springs. Others have leaf springs that might also serve as the end supports for the rod on which the roller travels. A bit of dirt or old, gummy lubricant in the supports or guides can keep the rod from moving freely to hold the roller snug against the coil as it turns. I'd avoid any conductive lubricants, including any lubricant that contains metal. Lubricants, especially silicon types, have a habit of migrating over time into places where they aren't wanted - such as across the turns of a roller inductor. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
