Secret Radio from World War II

The maker of this movie, Richard, PE0RIG, found this tin canned radio on a fleemarket in Eelde.The previous owner informed that he had cleaned the attic and the tin can was used by his father but he did not know for what purpose. It appeared to be a nice designed secret radio (radio receivers were not allowed in Holland during World War II). Apart from the Selenium rectifier which has been replaced by Richard, the radio was in good shape. It operates with a ECH21 tube (heptode and triode in one tube). A small transformer takes care of the 6.3 Vac filament voltage and provides 75Vac which is used (after being rectified) for the hi anode voltage. The carefully designed spiderweb coils control the amount of feedback to operate the reflex circuit. The audio level is loud enough to fill a small room.There is a multiposition switch that selects the fixed frequency broadcast stations. It appears that more of this type of radios were produced in the South of The Netherlands in 1944 and 1945 by Philips employees. . .