Day 7: Metal Detector

Worried a lot about today but things actually went very smoothly. Started taking one of the radios apart and testing the transistors to work out their connections. Made up a simple circuit board from the lid of a Tupperware box and started to solder up the components. Made up a simple oscillator circuit and wired it up to the search coil. Then made up another search coil and with a diode from the radios was able to make up a field strength meter and showed that the oscillator was working OK. Filmed this with Kathy. Then made up the second oscillator using the medium wave coil from the radio. This worked as well!!

Then wired up the mixer circuit and wired in the various oscillators and the audio amp from the smaller radio. Turned it on live and had it filmed and to my amazement it worked first time. It was low in volume but it worked!! Added the component and also an extra stage of audio amp and the metal detector was working. This was a nice stage to be in on day 2 of the first programme we have proved the "Rough Science" and so for me a major hurdle has been leapt.