17-02-2016, 03:36 PM
(17-02-2016, 10:14 AM)Terry Wrote:(16-02-2016, 11:25 PM)Pat Pending Wrote: ... The picture? Why a radio, of course!
Did this picture feature a genuine speaker fabric insert, by any chance?
No it didn't. Its a true crystal set that's permanently tuned to radio 5 live, and the peizo speaker (the ringer from an old landline phone) is bonded to the back of the canvas which acts as a sound board, during the hours of darkness its loud enough for comfortable listening, if the room is quiet. If you think you'd like to try using one of those peizos yourself, bear in mind that they can benefit from a series resistor or choke as they have a very high capacitance. He got the idea from a guy who posts designs for passive sets on the net. When I next visit I'll take some photos. It is a very good way to mount a frame antenna (provided the wall isn't to lossy!) What is life without whimsy! 
73. Andy
