After having worked with the RTL Dongle and the 30MHz. converter, I bought a second hand FiFi SDR receiver from Wim (PA0WVG). I started with extensive comparison between the RTL Dongle and the FiFi both in cooperation with multiple SDR software platforms on my pc (HDSDR, SDR Console, SDR sharp). I ended up with the simple software that was delivered with the FiFi receiver (a tailormade version of Bonito) and the RTL Dongle was promoted to be my receiver for VHF 2m. ham band and UHF 70cm. ham band.
In my situation the performance of the FiFi SDR receiver is significantly better than the performance of the RTL Dongle. I did a lot of experiments with 3 different antenna's. Particularly the homebrew Magnetic Loop antenne vor 14 MHz. gave me good results, but also the 'inverted v' antenna that I mentioned earlier is good.
However, again the 7Mhz. and 3,5MHz. ham bands gave a noise level of S6 to S9. So I still was not satisfied with my gear. Next follows a period of several months with experiments with adjustible filters. Some of them did something, other I threw away immediately.
And again Martin (PA0MWU) helped me out with a perfect filter, making a side note: "it works fine on 10MHz - 30MHz, but for the lower frequencies you'll have to build a separate one yourself". My first thought was: 'great plan' !! Martin had provided me with a detailled schematics of this filter and I started winding coils and soldering. And again a period of experimenting started. And again with little to no succes. What I've learned: I'm not good with soldering. All plugs that I soldered became a source of interference within 2 or 3 months. In the end the original filter that Martin gave me is still in use because it provides good results on 7-28MHz.
I tried to build both filters in one case, but that wasn't a succes.
In the mean time I decided I wanted more with the hobby. I started preparing for the official N and F examinations. After 2 and a have years, I leave Short Wave Listening (SWL) to those who have more patience and endurance.