Simple audio amp design...

[whit3rd]

On Saturday, January 1, 2022 at 6:06:19 PM UTC-8, bill....@ieee.org wrote:

On Sunday, January 2, 2022 at 6:56:44 AM UTC+11, palli...@gmail.com wrote:
Martin Brown posted:

In practice for economic reasons it is an argon rich trace nitrogen mix
at lowish pressure.

** Argon gas is many times MORE expensive the nitrogen for little benefit.

Phil hasn\'t got a clue how little gas it takes to fill a light-bulb. The cost of the gas is inconsequential.
All the lamps I see come from China or Indonesia.
Wanna find out for SURE what they use ??
You will need to pay a visit.

No. You can break a bulb in an evacuated space and use a mass-spectrometer to see the proportion of argon to nitrogen in the gas inside the bulb. A cheap time-of-flight mass spectrometer would do the job.

Or, maybe just pop the bulb into a microwave and look to see it glow? I\'d expect
low-pressure gas fill, so it should light up, like a dead-but-not-leaky fluorescent tube.

Argon has lines in the deep red, 6965 and 7067 angstroms; nitrogen has something at 5679 that
might be visible, but 5752 is for singly-ionized, safe to expect that.

University lab denizen, or glassblower, or neon signmaker, would be the best people to hook into such
a project.