But you can't test a 6H30 on it can you? It's not a 6DJ8 family so assume you use the Amplitrex.
Indeed, 6H30's can be characterized on the Tek 576 CT...I routinely evaluate triode section balance, within a tube, this way, as well as match between tubes. My current lab apparatus allows me to examine the 6H30, individually.
A custom test adapter is being fabricated for me so that I can A/B and characterize, simultaneously, a pair of 6H30's with respect to section balance within a tube and matching between tubes This should be much more efficient.