I purchased an Ameritron AL-811H amp. Per the tuning up instructions in the operator's manual on page 6, the plate current with no exciter drive should be 125 ma. My meter is indicating 175-180ma. Should I be concerned about this? I have the amp set for 240 volt operation. My line voltage reads about 241 volts. Other than this, the '811H still loads up per the operator manual.
What year was the amp made?
Tubes changed charateristics and started drawing more current. If it is an older amp without bias diodes, you might need to add about 3-4 volts of bias in the center tap lead. You can do that with a string of diodes.
Read this, especially 1, 2, and 4:http://www.w8ji.com/ameritron_811h_572_amplifier_trouble_shooting.htm