Discussion in 'Amateur Radio Equipment Reviews' started by N8FVJ, Oct 9, 2019.
While you're doing all the tube swapping, you might take a look at filament requirements too.
572B and 811A have same filament current draw. No issue swapping tubes, no modifications required.
you will find out...
Again both 811A & 572B are 6.3 volts @ 4 amp filaments. Despite W5LZ warnings, you can safely swap tubes. 1000s of Ham have done this.