I found this and other beautiful circuit drawings whilst foraging in the derelict back buildings and basement of the Rundfunk der DDR, Funkhaus Nalepastrasse. Even thought the main building is still used for recording and performance, the back buildings are a hive of discoveries for the explorer with skip-raking tendencies with all sorts of communicative artefacts lying around from 70's intercoms to glass tanks for battery making.

Greenfield Scalp transmitting station.