Posted by Tom Napier on November 20, 2013 at 06:58:13 user Didymus.
In Reply to: Re: Old images of Norfolk posted by Peter Ceresole on November 20, 2013 at 06:10:54:
Probably not a crystal set. My guess would be a two-valve radio running from a two-volt accumulator and a 120 volt dry battery. The first valve would be a regenerative detector (subject to squealing if misadjusted) followed by an audio amplifier to drive the headphones.
The real Hullaballoo device is the Decca portable gramophone further down the photos. I winced when I read the text.