Ian Field wrote:


"Ken Layton" wrote in message
...
On Friday, October 23, 2015 at 9:07:18 PM UTC-7, wrote:
Cylindrical. Axial leads.

Ordered caps for a speaker crossover because the leads had literally been
shaken out of the originals. But I had no luck finding those bulbs. I
would rather not jump it out. I guess I could and just put a beefier horn
in it.

It's called a "barreter". It's just a lamp used as a current limiter.

The earliest reference I could find to baretter was from the pioneering days
of wireless - apparently it was used as a detector.

The type I remember from the days of AC/DC TVs and radios was an iron wire
filament enclosed in a hydrogen filled envelope.

What did these tubes look like, any idea why they used iron and hydrogen?