----- Original Message -----
From: "R.Measures" <r@somis.org>
>> Rich,
>>
>> You are making an apples to oranges comparison. The issue isn't the
>> current carrying capability of the 8877 grid, it is the power
>> dissipation
>> of the grid.
>
> The grid has ESR. Current through R causes dissipation.
>
Yes, of course, Rich, but the ESR is not what is entirely
responsible for grid dissipipation due to grid current flowing
under conditions of excessive drive. If it were, the grid
drive voltage term would not appear in the calculation of
grid dissipation.
>> A capacitor has a power factor of ~0.0.
>
> Au has c. 60% of the conductance of Cu or Ag. Just because the grid
> has C does that mean there is no P dissipation in the grid?
No, of course not, Rich, but showing that a thin piece of gold
plated wire can carry 40 amps of RF current doesn't say anything
about how much power it can dissipate. The anode structure of a
tube has ESR too, but we don't calculate plate dissipation based on
I^2*ESR. We calculate plate dissipation based on Ep x Ip - Pout.
Changing the ESR of either structure won't necessarily change their
dissipation significantly (e.g. if I could make the ESR of the grid
or anode conductor zero, they would still dissipate power and get
hot due to the kinetic energy of the electrons hitting them).
73 de Mike, W4EF..................................................
>
>> ...
>
> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
>
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