by dcgillespie » Tue Aug 30, 2011 6:02 pm
No, the types of dual triodes you refer to and magic eye tubes are not enter-changeable in service application. You can add a magic eye tube to a device that otherwise does not have one, to (say) indicate when peak power output has been reached, but magic eye tubes cannot simply be installed in place of existing tubes that are already part of the originally design.
Dave