For LF/MF (2200m/630m), I am interested in the situation of a vertical antenna with capacitance hat top-loading, where the vertical antenna is VERY short compared to wavelength, and the antenna is brought to resonance across operational frequencies via suitable base inductive loading (i.e. variometer).
Given this situation, using antenna modeling I always end up with a resistance value significantly less then 50 ohm. When I calculate the necessary values for an LC impedance matching circuit, I end up with extremely high values necessary for capacitance (e.g. 50-60nF), which means variable capacitors are not a viable option.
What other options are available for matching a resistive component of less than 50 ohms? E.g. matching in the range of 5-10 ohms, to 50 ohm coax?
Could a "reverse" ferrite unun transformer work? E.g. 1:2, 1:4, 1:6? If so, suggestions for best approaches? What would be the implications for efficiency and limits on input power?