I won’t do that anymore because I’ve turned away from the EFHW antennas for some time and towards a 10.90m long inv-L multiband antenna.
I have shared my “wisdom” about the design and construction of EFHW impedance transformers several times on this reflector. All points to be considered can now also be found in the report Portable 7 Band EFHW Antenna by Stephan@HB9EAJ under this directory Technik und Software – HB9SOTA
73 gl, Heinz
Here are some details and photos for the construction of my EFHW couplers using the small #43 core from Fair-Rite:
- Housing: Camdenboss RX2008/S-5 (e.g. from Farnell)
- Ferrite core: Fair-Rite 2643625002
- Wire: 0.5 mm CuL
- Compensation capacitor: 100 pF/500 V (e.g. from Funkamateur online shop)
