> Since you have an essentially resistive, albeit wandering, load you
> might just use an old (thermocouple style) RF ammeter to calculate
> your power output. I'm assuming that the plasma tube exhibits a
> fairly constant voltage drop when ionized.
Most plasma tubes I've seen have reactance, and even if they
somehow don't have significant reactance there will be reactance
added from the mismatch in interconnecting leads.
That means you'd have to measure phase angle.
A directional coupler would be more accurate by far, exceeded only
by thermal measurements of load power.
73, Tom W8JI
W8JI@contesting.com
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