[mikethedruid]

Changing out tubes is the easiest of radio repairs. All you do is pull out the old tube and push in the new tube, being careful of the pin alignment. With octal and locktal tubes the center post takes care of the pin alignment automatically. With the older 4. 5, 6, and 7 pin tubes one must be more careful since they are aligned by having two pins that are slightly thicker diameter than the others. When you insert or remove these tube never hold them by the glass, this can separate the glass part from the base. Hold them by the base itself. I have found that the tubes are not a usual cause of static. Atmospheric conditions and man made sources are most common. Causes from problems in the set itself which are common include, failing resistors, failing paper condensers, dust in the variable condensers, and dirty or failing potentiometers. If your tubes all test OK, then check all the resistors. Any which have slipped out of tolerance should be replaced. I even replace the ones which are on the margin. When the set heats up working, it is probable that such a resistor will drift beyond tolerance. I always replace ALL the paper condensers and electrolytic condensers. I also carefully clean the variable condensers, making sure not to bend the plates. (Note, on some sets you might find SLIGHTLY bent outer plates in the variable condenser. These were often done AT THE FACTORY to help keep the alignment even across the tuning band. If they are not bent so as to short the plate beside, I leave them alone) I hope all these ideas help.