grundig: Looking for schematic
I have a Grundig SO 160ua that I am working on for a friend. I realized that the schematics listed for the SO 160 are not the same as for the SO 160ua, unless I'm doing something very wrong.
On the schematics for the 160, there is no EABC 80 tube and there's an EBF 89 but not an EF 89, as you can see from the tube location plan below.
Does anyone have the schematic or know what the difference is?
The EABC80 has an AM detector and and two diodes for FM.
The EBF89 adds two diodes for AM (audio and delayed AGC) to an EF89. Likely then there are two germanium diodes for FM detector. The EABC80 also has a triode for audio preamp. I don't know what is replacing that on the other model (maybe nothing or there is another tube you missed such as an ECC83)
Such changes betweeen other similar models are common by 1960s as the price of semiconductors fell (the tube portable sets in 1950s with VHF-FM always used semiconductor diodes on FM to save power).