How to make a radio

Search for crystal radio or "foxhole radio". You will need something to tune the radio, usually a coil and capacitor, something to detect the signal (convert from the electrical equivalent of radio waves to sound waves) which can be a packaged diode or one made from common parts, such as a crystal (usually galena, aka iron pyrite), an old razor blade, or a pencil lead, and something to convert the electricity to sound, which is usually a crystal or magnetic earphone.

So you will need some parts, but not many, and you may be able to improvise them.

When I was a child, I used to make radio coils out of empty toilet paper rolls. Much to my wife's chagrin, I still automacticly save them, although I have not made such a coil in well over 20 years.

Geoff.

You will need a long wire antenna - 20+ meters - unless you are located very near to a broadcast station. A ground connection helps as well.

Iron pyrite (aka fool's gold) is iron sulfide. Galena is lead sulfide. Either will work as a detector diode.

Bryce (crystal set user in 1953!)

You must have a few thousand by now ( --

WW wrote:

For a diode, you may wish to 1st start with the venerable 1N34A germanium diode. Once you have the other circuit components working the way you wish, you could step back in history then, and go with the cat whisker detector.

Google "crystal radio sets" for lots more.

On 10/19/2009 7:24 AM Geoffrey S. Mendelson spake thus:

Well, that's one way to go.

But since the OP allowed the use of active devices (e.g., transistors), just not ICs, why not build a "real" radio? But simple: how about the world's most primitive superhet AM radio? or maybe just a "crystal set" but with an audio amp to increase sensitivity? And how about tubes instead of transistors?

I'd like to see some circuits for such projects. Say something that runs off a 9-volt battery, maybe with 1, 2 or 3 transistors.

As a seventies kid here in the UK, we had the wonderful Ladybird book - 'Making A Transistor Radio'.

The TRF project was a short plank of wood, some screws and brass cup washers, electronic bits and not a soldering iron in sight!

Some related web sites on that.

Superhet might be a little more than they can deal with and get aligned but what about a regenerative? It offers simplicity with reasonable sensitivity and a 'look what I did' factor.

G=B2

Done that, back when I was about six. Big coil, cap, long wire antenna.

A few have forgotten I think, no batteries. But an antenna can actually pick up power. You may tune the desired frequency for reception and feed it to headphones, but now I am thinking that the extra power coulod be used to run a local oscillator and then you have a hetrodyne reciever. Much better and easire to tune.

Intersting.

JURB

Check eBay for inexpensive AM radio kits. Radio shack sold many of these for kids in the 60s to 80s The kit includes all the needed parts mounted so that you only have to hook up wires between the parts. A small instruction book explains the basic operation.

In message , Adrian C writes

Holy cr.. £40!!!! Wow, I better start digging out my old Ladybird books, I have that exact book somewhere.

My first transistor radio project, made me go all dewy eyed remembering that and building it with my grandfather. Thank you for posting that.

Heh, that's nothing :-)

Someone in the UK has it for sale on Amazon marketplace for £109!

And not so near can still work with this simple setup using a cristal earphone.

What are you going to use for primitive headphones?

TMT