Jim,
That is such a revolutionary statement that I felt I must investigate
it. So I loosely wound 4 turns of PTFE wire on a Type 43 toroid - the
wire was barely touching the toroid. The impedance measured around 200
Ohms at 10MHz - almost entirely resistive. I connected it across my
tuner, adjusted for a good match, and then applied 20W at 10MHz for 5
minutes.
At the end of 5 minutes I touched the wire and then the toroid. The wire
was barely warm, but I scolded my finger on the toroid!
There's no doubt at all that the dissipation mechanism is within the
ferrite toroid, not the wire; if the wire gets hot it's because it's in
contact with the toroid.
Or perhaps I completely misunderstood what you are claiming?
Steve G3TXQ
On 10/02/2015 21:18, Jim Brown wrote:
There is dissipation in a ferrite core choke in the resistance coupled
from the ferrite core. It is the coax shield that gets hot, not the
ferrite (although the heat in the coax may be transferred to the
ferrite material).
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|