Startup filament current
I checked the filament current when the set is turned on and found it peaked at about 1 amp then settled down to 600mA after 10 seconds. That's with a single CL-90 (120 ohms cold) in place of the original thermistor (400 ohms cold).
I then tried it with two CL-90s in series and got a peak or around 850mA before settling down to 580mA.
I checked in my RCA tube manual but couldn't find any data about permissible cold filament startup currents.
Does anyone know if it's OK to have 1A (or more) running through a 600mA tube for a few seconds every time a set is turned on ?
If not, I could go with three CL-90s in series to really keep that current surge down.
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