Today I made two transformers with ft114-43 and connected them back to back and found out that almost half of the power is lost (as heat) indicating almost 1.5dB per transformer.
Of course this was very simple measurement using two power meters and dummy load and it does not tell the real thing at all.
While trying to figure this out and wondering if I my core materials are really what they should be, I ran into this http://w7zoi.net/xfmrsefhw.html
Just wondering if anyone else has measured these famous efhw transformers with diffirent core materials? Oh yes, I know it is only one dB, but thats not the point here.
73 Marko OH9XX OH3XR