thanks Gary, clear! I have replaced the primary cap with an MMC (9cap(10nF,1.6kV)in series, two series in parallel). Well now all work well.... I have some problems because the tube become red after few second (in full power mode) but I think that this is the limit of my tube (RK715). thanks for support, Andrea _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla