Build a Foxhole Radio
During World War II, GIs in the field built
really amazing simple radios to listen too. These were made with materials that
they could get their hands on and were small enough to carry around in a big
pocket. You can modify this design if you want to set it up so that it’s tune
able too!
Now we will make same radio with War World II.
Let’s Do It!
Material
- Toilet paper
tube
- Razor blade (If you can
find a blue one like the “PAL super single Edge” then great . Otherwise, you’ll
have to blue it by heating it up)
- Earphone
- Large safety
pin
- Wood pencil
stub
- Magnet wire
- A scrap of
wood
- Paper clips
- Tacks
- Battery
Make It!
The Coil – I made this with
magnet wire I had lying around. I’ve seen radios made with really thin wire,
like I used, to thicker wire almost as thick as a staple. I used tape to hold it
to the card boar tube, but in retrospect, poking a hole and tying it on would be
better. Wrap the wire around the tube 120 times and take time to make it smooth
together. I kept getting distracted from counting, so I ended up counting after
winding. If it’s not exact, it shouldn’t be a problem. The amount of coils does
matter for the radio station. If you get a station in sort a good, but it’s not
perfect, you may be able to correct that by adding extra loops.
The Detector – Soldiers were
given blue razor blades as part of their supplies. The bluing is some sort of
oxidized coating from getting heated up, it probably keeps it sharper for
longer. My research says that a rusted razor blade may work too. For me, I blued
it with a propane torch and when I wiped it off after it had cooled, there was a
layer of oxide on it and it was blue and purplish gray. I tried rusting a razor
blade, but maybe it was stainless steel or something because it just wouldn’t
rust. Salt water would be the way to do it, but just wasn’t patient
enough!
The Cat Whisker – Take a pencil
stub and poke the graphite with a safety pin. This works as a diode, but this is
magic to me. If you can explain it simply, drop a note in the
comments!
Earphone – I used an old-school
earphone from my bat detector project last year, but if you don’t have one, I
would try out the earphones you already have before buying a new one.
Antenna – I stripped a cat6 cable
and used one wire to hang out the window. My Wire is about 25 feet long, but
longer is better!
Ground – I attached a wire onto
the radiator. If you don’t have a radiator you could drive a coat hanger into
the ground and wind a wire to that.
Battery - Connect the battery to ground and seeing what will happen
with the radio
Hook it all together – I used
brass tacks to keep it all together and paperclips to connect all the
wires.
Making it work – the first time I
tried this, it didn’t work. It was frustrating, but I just went through my
materials, blued the razor and it worked. The second time I tried to get it
work, I couldn’t get a station, I just got buzz. I played with everything and
finally figured out that the ground connection wasn’t very good. When I fixed
that, I was able to hear sports talk radio! One of interesting things is that it
works better or worse depending on where you put the pencil lead on the razor
blade. If it doesn’t work the first time, don’t give up! Every project you work
on can have 100% success as long as you don’t mind mistakes and redoing
things!
There are a lot of sources for you to learn more. I used this to search to do
research!
Http://www.google.com/search?q=foxhole+radios
Reference : Weekend Project ( Make Technology on
Your time )
