Radio receiver - 12y lad wants to know & build ?

[tamborine]

On Antiques Roadshow there was a radio receiver made by POW. It was made with metal bits found on camp and had earphones attached.

What are the basic components needed to make one ?

[NazNomad]

http://bizarrelabs.com/foxhole.htm

[NazNomad]

* Razor blade "PAL Super Single Edge" by American Safety Razor Co., or a regular rusty one
* Cardboard toilet paper tube
* Wire coat hanger or other handy strip of workable metal
* Headphones or earphone (2 - 4 K ohms)
* Large safety pin
* Lead from a wooden pencil
* #22 AWG (or so) wire
* Something for a base (small scrap of wood)
* Lacquer, glue
* Small tacks or screws for fastening components

[bookbinder]

Google DIY Radio Receiver Kit.

[tamborine]

lead from a pencil Naz - what does that do ?

[ChuckFickens]

Becomes part of a point contact diode.

[tamborine]

it says galena, a sort of crystal. Would this be magnetic ? I've got lots of agates that look similar.

Thanx for info, the house is being ransacked for bits :)

[squarebear]

"it says galena, a sort of crystal."

and he found this just lieing around on a POW camp??

[ChuckFickens]

You don't need a crystal for the one Naz has described, the razor blade, safety pin and pencil lead take the place of a crystal and is the detector in the circuit.

[Old_Geezer]

Yeah but did they get DAB on it ?

[jomifl]

Galena is lead sulphide and is not magnetic

[jomifl]

My brother once made a receiver based on a semiconucting crystal of ferric carbonate (or oxide) found on a rusty cast iron drainpipie.

[tamborine]

Further instruction says a pea sized piece of coke/coal. Easily got in Buchenwald :(

[heathfield]

You'll still need headphones. POWs had to obtain them by stealth, i.e., they pinched them, or had them smuggled into camp.

[tamborine]

he's fixing in earphones. Will report further when he's done. thanx all

[Buenchico]

If the youngster decides that doing it the PoW way is a bit too difficult, buy him one of these (along with a cheap soldering iron and some multi-core solder):
http://www.maplin.co....stal-radio-kit-220060
I loved playing around with such things when I was that age ;-)

Chris

[beso]

I made a radio receiver when I was about 13 and used it for about four years.

I wasn't a purist and just used a germanium diode as the detector. I had proper high impedance headphones and it worked really well with my bed frame as the aerial and the earth from the mains power point.

It was a great solution in a house where my mother hated music and didn't like the radio on. I couldn't afford to buy a radio. They were still quite expensive in the early seventies and I had very little money.