To show more details here is at first the open 54x54mm block with two pencil tubes 2G21 as 2-stage-AF-amplifier (incl. a germanium diode as demodulator) as a replacement for the DAF11 – same size as the legacy system #8054 (2-stage-transistor amplifier 😉
the next one shows the DM70 in turquoise with the question mark symbol. full colored symbol = no / bad signal, the less color the better the radio station signal. On the right the mentioned block with a pencil tube socket for testing reasons.
Last but not least the different two main outlines of the steel tubes, left old version until 1942/43 (with the special socket) and to the right the lower ones as follow-on to save material (steel, nickel, brass, bakelite). These tubes were used until 1951 for portable radios (no new production, only using up NOS inventories) until the subminiature 7-pole glass tubes were available (DK91, DF91, DAF91, DL92 etc.). Please note the right tube with proof date 10/44 = it’s my year of birth…
If anybody has interest to build this receiver with the tube lineup DCH11-DF11-DAF11-DL11, I still have several pieces for sale…
- This reply was modified 2 years, 6 months ago by Michael. Reason: Changed font and size styling for easier reading