I bought a SABA Freiburg WIII in fully restored condition. The visual appearance is like new inside and outside, but the functioning is not perfect: there is a slight hum (power supply filter cap? or grounding problem?), the magic eye is dim, the Medium wave only receives one station with the built-in ferrite antenna, there is a crackle if I knock the enclosure (intermittent solder joint?). I am a retired electronic engineer from California now living in Belgium. I have no tools or test instrume…