[Bobalu]

That’s interesting :-)

I have been making a few rf transformers myself.
Using F240-43 cores. three of them stacked to handle
1kw at hf.

You must be using some tiny cores.

[Red Badger]

Yes, binocular and toroids mostly.

B and J material.................

[Red Badger]

One thing I have learned is that the more ferrite material you use the less intermodulation you will have.

Keeping the cores from saturating at high power will make more power available at the output and less intermods.

So, if you need more power or there is too much loss, add another core....................