On Sat, Sep 14, 2013 at 06:35:39PM -0400, Robert Eleazer wrote: > So you might try plugging in a fresh tube. Thank you. I've found the problem and it's working fine now. I have not another 6F7 so testing other tube should need at least an adapter for the UX to octal. -- 73 de Fer, LU2DFM