It turned out that my father had himself found it as he was clearing out his childhood home many years before and that it had belonged to my grandfather who died in 1959.
It covers longwave, medium wave and three shortwave bands from 5.5 to 21 MHz. I had never before seen a radio with a dial given in meters rather than kHz or MHz, but I have later understood that that was not uncommon for pre world war II radios.
Since the back was missing, I had no information about age or type. The tubes which were all in the 11-series suggested the end of the thirties, but here it turned out that the dial had valuable information.
The medium wave part of the dial had a separate side on the left hand for German stations and here one can find cities that are no longer in Germany such as Königsberg on 223 m and 291 m (1348 and 1031 kHz). Today this is Kaliningrad in Russia. The dial also showed Danzig on 230 m (1303 kHz), ”Schles. G. W.” (Schlesische Gleichwelle - a single frequency net with stations in Gleiwitz and Reichenbach/Oberlausitz) on 244 m (1231 kHz), and Breslau (315 m - 950 kHz). Today these are the cities of Gdansk, Gliwice and Wroclaw in Poland. At least the radio must have been from before the end of WW2.
September 1939. Today Troppau is called Opava and lies in the Czech Republic. Troppau lies in that area which Germany annexed on 30. September 1938. Finally one can find Memel on 531 m (565 kHz). This city is today called Klaipeda and lies in Lithuania. It was occupied on 22. March 1939.
Thus the conclusion of this historic search across the dial is that the radio dates from some time between March and September 1939.
The output tube and the rectifier were missing, and it was natural to look for tubes in the same 11-series. I was not able to find this particular radio in the large archives of the Norwegian Radio History Society, but there was documentation for a few other Blaupunkts there. From their descriptions I could guess EL11 for the output tube. Measuring the filament voltage for the rectifier gave 4 Volts, so then AZ11 was a good choice.
With some excitement I turned on the voltage for the first time, and to be on the safe side I connected it in series with a 60 W light bulb to reduce the voltage. No explosion! As incredible as it sounds, with full voltage it actually produced sound. But unfortunately after a few seconds everything disappeared. One evening with diagnosis of the radio and I could isolate the problem to the beginning of the audio section and two rotten shielded cables connecting audio in and out of the pentode in the magic eye. Not everything is as new after 60 years! After having replaced the cables the radio was perfect, and even the magic eye and the dial lamps functioned. In my experience the magic eye is often weak and in the Oslo region the dial lamps for the longwave band may have burnt out as the local station used to be on 218 kHz.
Some weeks later as I was about to clean the dial for dust I disassembled the glass in the front and found an inscription saying Blaupunkt 7W79 and the date 28.3.39. So the result of my detective search wasn't too bad! In fact the dial was produced with an updated name just 6 days after the occupation of Memel/Klaipeda.
This radio cannot have been more than a couple years old when all radios were confiscated in Norway in 1941. Imagine how sad it must have been to give up such a nice and costly radio at that time! This must also have been one of the few radios that actually were returned to their rightful owners in 1945.
Now the radio has a prominent place in my house and every time it is turned on it is a reminder of both the history of my family and of a turbulent era in the history of Central Europe.
First published as "Min farfars Blaupunkt radio" in Hallo Hallo of the Norwegian Radio History Society, September 2001, updated in 2013. © Sverre Holm