How many watts do you then suppose is being dissipated in a trap on your
average tribander running at 1500watts out?
Just a typical number. Take the worst case scenario. Empiricist that I am, I
would bet it's less than 10 watts per trap, and hardly significant. You would
need to be losing at least 50-100 W per trap to even be able to notice any
difference on the receiving end using instruments, let alone with the human ear.
Don't burn your fingers on those traps :)
Best regards - Brian Carling
AF4K Crystals Co.
117 Sterling Pine St.
Sanford, FL 32773
Tel: +USA 321-262-5471
> On Apr 14, 2015, at 1:16 PM, Doug Smith <doug@w7kf.com> wrote:
>
> 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
>
>
>> 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.
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|