I'm thrilled to unveil my new 3D printed AM radio! I was inspired by the diy crystal and foxhole radios of the early 1900's, but I created my own design to be as simple as possible.
I put a lot of work into the video. It should explain everything so check it out and thanks for watching!
Step 1: Materials
Download link for 3D model: https://www.thingiverse.com/thing:2752141
1 Piezo Earphone
1 Coil of 24 AWG Magnet Wire (aka Enamel Wire)
1 1N34A germanium diode
1 small piece of aluminum foil
1 paper clip
1 package of Hildie & Jo 45 Cord Ends (5x10mm Springs)
These should be easy to find online. The springs I got are sold at Joann Fabrics. Search Silver Cord End Springs but any similar 5mm diameter springs should work.
Step 2: Overview
I think it is important to show you an overview of the circuit and how everything will hook together before we get started.
Step 3: The Coil
This is a very important part. Wind the wire tightly around the 3d printed coil holder and make sure there is no overlapping and that each layer is tightly pressed together. Take this part slowly and use tape to hold the ends and tape it if you need a break. See the video for reference.
Then we need some of the metal revealed on the front so use some sandpaper to gently remove some of the enamel. Too much sanding may cause the metal to short out. Wipe away any sandings when done.
Step 4: Assemble 3D Print
The coil holder will slide securely into the printed base. Feed the left side wire thought the small hole on the base and clip to the side. The right side will go into the right side spring but sand off the enamel first so it makes contact.
Step 5: Paperclip, Diode, and Earphone
Open the paperclip and flatten it. This will fit into the two sides of the base. It should be close to the coil without touching it. Cut and sand off the ends of a small piece of wire to connect the paperclip to the left side spring.
Attach the diode in between the left and center springs. Either direction will work.
Attach the piezo earphone to the center and right springs.
Step 6: Tuner
Cut and fold a small piece of foil and loop it through the paperclip and wire coil. It should touch both the paperclip and coil of wire. Fold it through the printed tuner.
Step 7: Setup
The antenna wire should be layed out flat about 15 to 20 feet or more and go into the left spring. The longer the better. Sand a few inches off the end of the ground wire and wrap it securely around the metal sink faucet. Connect the other end of the ground wire to the right side spring. Sand the enamel off this end too.
Step 8: How to Use
Slowly slide the tuner back and forth and you should hear faint static sound and eventually you will find a radio station!
Connect to an amplifier if the volume is too low.
Make sure everything is connected correctly, reference the video.
Metal objects and also your body can affect the radio so occasionally step back.
Make sure all connecting wires are sanded to expose the copper for best connections.
Play with the antenna. Try to tape it up higher, change the direction, or make it longer.
I hope you enjoyed this! Thank you and see you next time. :)
Step 9: Alternative
This is just an option. The diode can be replaced with a safety pin pressed into the lead of a pencil tip that makes a point contact on a razor blade that has been heated until it turns blue. This will allow current to only flow in one direction just like the diode. This is much harder to get working but it is possible.
I like to make 3D animations, 3D programming, and 3D printing on my channel so subscribe to see more! www.youtube.com/c/3dsage