One of many interesting objects I noticed yesterday, while walking around Standen House, was this 1920s Crystal Set. Its basically an AM wireless for one or two people to listen via headphones to the LW and MW broadcasts of the day. It requires no batteries or mains plug because there is enough energy in local transmissions to drive high impedance headphones. All that is required is a long aerial wire, an earth connection, and a servicable detector (in this case a "cat's whisker"). This set originally cost over £5, a tidy sum in the mid-1920s, and certainly beyond the reach of either set of my grandparents. But by the early 1960s, I was able to build my first crystal set from bits robbed from old radio and tv chassis (a germanium diode used in place of a cat's whisker). So it set me wondering. I believe some POWs were able to secretly build simply radios like this during WW2. Where did they get the parts? And how were they smuggled into the camps?