Subj : 572B usage in an 811A To : HAM_TECH From : Alan Beck Date : Thu Oct 11 2018 09:36 am Hi there, I am looking for advice on something I am doing right now with my Ameritron AL-811H amp. The 572 two 572B tube I had new dropped down in power to 300 Watts. DX Engineering will be sending new tubes. Currently, I measured the plate current on each tube in the amp. I found the following currents of what I put in the amp to achive just 500 watts. 600 ma 150 ma 85 ma 75 ma Now, my question is if One of the tubes fails, can it damage my amp. What is my worst case scenario here? I think I might keep these tubes in it until the power drops and then out the new ones in. 73, Alan VY2XU --- WinPoint Beta 5 (359.1) * Origin: Original WinPoint Origin! (1:229/426.36) .