We often see statements by hams where they draw inference from observed temperature rise of a ferrite core at RF. Lets consider the following statement.
The FT-240-43 balun MUST be quite efficient as it barely increased in temperature over a 5 minute over at 100W on SSB.
For the purpose of this explanation, lets assume barely increased in temperature
means 5° increase in temperature from cold. Under these conditions, we can reasonably assume that almost all of the heat input to the core is consumed in raising the core temperature. Continue reading Interpreting temperature rise in ferrite cored RF transformers and inductors