Loading the antenna connection with 0.25W metal film resistors between 39 Ohms and 390 Ohms, good results were achieved at 1.8MHz. At high frequencies ( 28MHz) the influence of their self inductances were noticeable. A shortcut wire and an open connector showed the influence if self inductance and stray capacitance. 50 Ohms and 75 Ohms dummyloads showed perfect results at least up to 70MHz.
Adjusting the optimal tap on a 80m-ringcore-matching-auto-transformer was easy, fast and straight forward.