3 ms·
That was my immediate thought also, but vacuum tubes I know commonly use 6.3V AC.
by eimrine 4y ago
That was my immediate thought also, but vacuum tubes I know commonly use 6.3V AC.
- jacquesm 4y agoNot necessarily, they would run just fine of lead acid cells, 3 of which produce... 6.3V DC.
- makomk 4y agoThe filaments will run off either AC or DC because they're basically just heaters. AC became the norm in mains-powered devices after electrification took off, but a lot of the early radios were powered by DC from batteries - initially this was seperate, possibly rechargable, low voltage battery for the filament supply and a disposable high-voltage battery, with the second battery being replaced by step-up devices using vibrators and transformers fairly early on.
- h2odragon 4y agohttps://en.wikipedia.org/wiki/Vacuum_tube_battery https://en.wikipedia.org/wiki/Vacuum_tube_battery Up to 120VDC early on