In August 1941, the Germans were busy invading the Soviet Union, but they would have realize the futility if they had known that the Soviets were quite undaunted, and were busy putting together crystal sets. As you can see from the August 1941 issue of Радиофронт (Radio Front) magazine, that is exactly what they were doing. The diagram shown above is clearly a crystal set, and most of the parts appear to be homemade. Despite what the Germans could throw at them, the Soviets were still able to pull in the stronger stations thanks to simple receivers such as this one.

As you can see from the diagrams below, the tuning was accomplished with a variometer, using two spiderweb-style coils hinged together. And as long as they could find a suitable mineral, the Soviets could easily put together the detector shown below.