[tbone]

Recently I’ve tested and swapped tubes in a few radios to get the best performance, or at least the theory that my radio is working better. I’ve measured AVC and Power Supply voltages too.

I’ve seen certain brands like National Union NIB and the like test not as good as some major brands. I think the way tubes were mass produced, they had minimum specs to meet, and if they did, out they went for sale. Military tubes are supposed to be built to better standards, so it’s possible that they can test better.

The bottom line, unless it’s a high end amplifier that needs matched pairs, most tubes are fine. Most radios will never notice the difference, even with a weak tube. You’d be surprised how good a radio with weak 45’s can still sound.