[Hallicrafters] SR-400A PA cathode resistors

[Walt Cates]

On virtually all of the 400A's I have worked on the 13 ohm resistors in the cathode ckts have been discolored. They measure from 19 to 25 ohms. I have always replaced them and went on. My 400A which I restored only about a year ago had the same "problem" when I got it. After one year and probably less than 10 hours of actual TX time the power has began to drop off. I opened it today and you guessed it the 13 ohm resistors are way out of tolerance again. I haven't determined if this is the cause of the power drop off yet. But, I thought I would quarry the group to see if there have been any changes or improvements that I haven't heard of.

Best Regards, Walt Cates, WD0GOF, http://www.myhamshack.com/WD0GOF/<http://www.myhamshack.com/WD0GOF/>