>
>> This time about the 3CX800A7 Tube. What is the maximum allowable Plate
>> Current of a 3CX800A7 Tube ?? Can it be operated at 600 ma without
>> degradation or damage ???
>
>Tubes do not live happily for many years at 500mA, and then
>suddenly die if you run 20% more current.
>
>As a matter of fact, current has little if any effect on life as long as
>you don't exceed the peak emission current of a MOX cathode tube.
>
>With thoriated tungsten, like an 813, you can hammer the heck out
>of the emission with no ill effects at all.
>
>3CX800's actually have a published IVS (intermittent voice service)
>rating that exceeds the value in the typical operation tube tables. I
>don't have that data handy, but you would certainly be fine at 20%
>over normal ratings as long as you don't exceed the dissipation
>rating of any elements and have the rated filament voltage applied.
>
>Excessively low heater voltage is the real enemy of MOX cathode
>tubes being operated at the max.
// However, too much heater potential causes barium to migrate from the
cathode to the grid. The limit is +/- 5%.
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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