Losses in an inductor are related to both the Q of the inductor and the current
flowing through it.
Simplistically, one could think of it as: P(loss) = I^2 * R.
So, given the same Q, in a high voltage, low current scenario (like the RF tank
coil in your amp) the losses will be less than in a higher current, lower
voltage scenario (antenna trap).
Inductors in antenna traps are usually low Q affairs due to the physical
constraints imposed upon them. Thus, higher losses even without any
operational faults such as you describe. And, they’re usually in a fairly high
current area of the antenna. Again, resulting in higher losses..
I have an inductor in an L-network that, on 80 meters, has 17 amps flowing
through it. You can bet your last dollar I have taken every step possible to
make sure the Q of that inductor is as high as I can make it. (Huge, silver
plated, enclosure is non-conductive, etc.) That inductor is MUCH larger than
the tank coil in the amp driving it. But it has much more ability to make heat
than the inductor in the tank circuit, due to the nature of the circuit it is
in. It has many more amps flowing through it even though the amount of power
is the same (1.5 KW).
73,
Doug, W7KF
http://www.w7kf.com <http://www.w7kf.com/>
> On Apr 14, 2015, at 10:32 AM, Bry Carling AF4K <bcarling@cfl.rr.com> wrote:
>
> Then there would also be the issue of your RF tank coil in a linear amplifier
> being similarly
> "metal enclosed." Somehow I am not seeing your point.
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