- 2024
- Oct
- 6
That weird lightbulb in Heathkit - and other - test equipment.
If you’ve ever opened an audio generator from the tube era, chances are you’ve seen one of these in the circuit.
That’s a GE type 11098 - 3S6/5 - a 3W, 115V lamp. It’s used as a balance element for the oscillator in those devices. It acts like a PTC resistor.
The generator I picked up recently at the Piketon Hamfest has a slightly unbalanced output, with the bottom of the signal being flattened. While I assume there are probably some capacitors in there that are bad, it was suggested that I try this lamp. (Maybe…I did find a post where one of these simply needed new tubes and a tune-up.)
They seem to be widely available, as they’re some sort of emergency lighting bulb. I’m planning on ordering some and will give it a try - stay tuned for results!