[AMPS] dielectrics

[John T. M. Lyles]

W8JI said:

>When you look around and see the industry avoiding a method
>there is almost always a good reason. In this case they are
>probably concerned about loss of Q and heating of the component.
>
>Dissipation factor is the ratio of energy dissipated to energy stored
>per cycle. The dissipation factor would increase greatly if you pick
>the wrong material.
>
>As a second effect when you add a dielectric, energy is more
>concentrated. There is more current in a smaller area. That also
>can increase losses if you don't plan for it.
>
>A third effect is drift. The component will change values with
>temperature.
>
>You need to look at more than capacitance.
>
>Many materials also have an increase in dissipation factor with
>temperature.

Couldn't have said it better Tom, thanks for saying that. Before we 
all get to filling our variables with fluid. I don't know any 
dielectric that is better than air for loss tangent and for 
stability. Well, vacuum is one....

John
K5PRO
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