15-07-2015, 11:43 AM
Nick,
I think you may have a problem with power dissipation in the anode supply pot. If I've got my sums right the standing current in the pot will be 66mA (198/3000 = 0.066A), which means that it'll be dissipating just over 13 watts even before you take into account the triode. That's quite a big pot!
As Lawrence has suggested you could use a higher value and that would reduce the standing current. Whatever value you go for though this will be dissipating power and it'll probably always need to be a wirewound pot rather than a carbon film one.
Hugh
I think you may have a problem with power dissipation in the anode supply pot. If I've got my sums right the standing current in the pot will be 66mA (198/3000 = 0.066A), which means that it'll be dissipating just over 13 watts even before you take into account the triode. That's quite a big pot!
As Lawrence has suggested you could use a higher value and that would reduce the standing current. Whatever value you go for though this will be dissipating power and it'll probably always need to be a wirewound pot rather than a carbon film one.
Hugh
